CONTENTS

SECTION 1 GENERAL

Group 1 Safety Hints -------------------------------------------------------------------------------------------------------- 1-1

Group 2 Specifications ----------------------------------------------------------------------------------------------------- 1-10
Group 3 Operational Checkout Record Sheet --------------------------------------------------------------- 1-23

SECTION 2 ENGINE

Group 1 Structure and Function -------------------------------------------------------------------------------------- 2-1

Group 2 Engine speed and Stall rpm ----------------------------------------------------------------------------- 2-14
Group 3 Fuel warmer system ------------------------------------------------------------------------------------------ 2-15
Group 4 Fan drive circuit for cooling system ------------------------------------------------------------------ 2-16

SECTION 3 POWER TRAIN SYSTEM

Group 1 Structure and Function -------------------------------------------------------------------------------------- 3-1

Group 2 Operational Checks and Troubleshooting ------------------------------------------------------- 3-58
Group 3 Test and Adjustments ---------------------------------------------------------------------------------------- 3-69
Group 4 Disassembly and Assembly ----------------------------------------------------------------------------- 3-71

SECTION 4 BRAKE SYSTEM

Group 1 Structure and Function -------------------------------------------------------------------------------------- 4-1

Group 2 Operational Checks and Troubleshooting ------------------------------------------------------- 4-29
Group 3 Tests and Adjustments -------------------------------------------------------------------------------------- 4-36
Group 4 Disassembly and assembly ------------------------------------------------------------------------------ 4-38

SECTION 5 STEERING SYSTEM

Group 1 Structure and Function -------------------------------------------------------------------------------------- 5-1

Group 2 Operational Checks and Troubleshooting ------------------------------------------------------- 5-18
Group 3 Tests and Adjustments -------------------------------------------------------------------------------------- 5-26
Group 4 Disassembly and Assembly ----------------------------------------------------------------------------- 5-34

SECTION 6 WORK EQUIPMENT

Group 1 Structure and Function -------------------------------------------------------------------------------------- 6-1

Group 2 Operational Checks and Troubleshooting ------------------------------------------------------- 6-41
Group 3 Tests and Adjustments -------------------------------------------------------------------------------------- 6-52
Group 4 Disassembly and Assembly ----------------------------------------------------------------------------- 6-67

0-9
SECTION 7 ELECTRICAL SYSTEM

Group 1 Component Location --------------------------------------------------------------------------------------- 7-1

Group 2 Electrical Circuit ----------------------------------------------------------------------------------------------- 7-3
Group 3 Monitoring System ------------------------------------------------------------------------------------------ 7-21
Group 4 Electrical Component Specification --------------------------------------------------------------- 7-51
Group 5 Connectors ------------------------------------------------------------------------------------------------------- 7-58
Group 6 Troubleshooting ------------------------------------------------------------------------------------------------ 7-78

0-10
 FOREWORD

1. STRUCTURE
This service manual has been prepared as an aid to improve the quality of repairs by giving the
serviceman an accurate understanding of the product and by showing him the correct way to
perform repairs and make judgements. Make sure you understand the contents of this manual and
use it to full effect at every opportunity.
This service manual mainly contains the necessary technical information for operations performed in
a service workshop.
For ease of understanding, the manual is divided into the following sections.

Structure and function

This group explains the structure and function of each component. It serves not only to give an
understanding of the structure, but also serves as reference material for troubleshooting.
Operational checks and troubleshooting
This group explains the system operational checks and troubleshooting charts correlating problem to
remedy.
Tests and adjustments
This group explains checks to be amide before and after performing repairs, as well as adjustments
to be made at completion of the checks and repairs.
Disassembly and assembly
This section explains the order to be followed when removing, installing, disassembling or
assembling each component, as well as precautions to be taken for these operations.

The specifications contained in this shop manual are subject to change at any time and without any
advance notice. Contact your Hyundai distributor for the latest information.

0-1
2. HOW TO READ THE SERVICE MANUAL
Distribution and updating Revised edition mark (ΗΘΙÄ)
Any additions, amendments or other changes When a manual is revised, an edition mark is
will be sent to HYUNDAI distributors. recorded on the bottom outside corner of the
Get the most up-to-date information before you pages.
start any work.
Revisions
Filing method Revised pages are shown at the list of revised
1. See the page number on the bottom of the pages on the between the contents page and
page. section 1 page.
File the pages in correct order.
2. Following examples shows how to read the Symbols
page number. So that the shop manual can be of ample
Example 1 practical use, important places for safety and
3-3 quality are marked with the following symbols.
Section number (3. Power train
system)
Consecutive page number for Symbol Item Remarks
each section.
Special safety precautions are
3. Additional pages : Additional pages are necessary when performing the
indicated by a hyphen(-) and number after the work.
Safety
page number. File as in the example. Extra special safety precautions
10 - 4 are necessary when performing
10 - 4 - 1 the work because it is under
Added pages internal pressure.
10 - 4 - 2
10 - 5 Special technical precautions or

ö Caution
other precautions for preserving
standards are necessary when
performing the work.

0-2
 3. CONVERSION TABLE
Method of using the Conversion Table
The Conversion Table in this section is provided to enable simple conversion of figures. For details of
the method of using the Conversion Table, see the example given below.

Example
1. Method of using the Conversion Table to convert from millimeters to inches
Convert 55 mm into inches.
(1) Locate the number 50 in the vertical column at the left side, take this as ͽ, then draw a horizontal
line from ͽ.
(2) Locate the number 5in the row across the top, take this as ;, then draw a perpendicular line
down from ;.
(3) Take the point where the two lines cross as Ϳ. This point Ϳ gives the value when converting
from millimeters to inches. Therefore, 55 mm = 2.165 inches.

2. Convert 550 mm into inches.

(1) The number 550 does not appear in the table, so divide by 10 (move the decimal point one place
to the left) to convert it to 55 mm.
(2) Carry out the same procedure as above to convert 55 mm to 2.165 inches.
(3) The original value (550 mm) was divided by 10, so multiply 2.165 inches by 10 (move the decimal
point one place to the right) to return to the original value.
This gives 550 mm = 21.65 inches.

Millimeters to inches ;
1mm = 0.03937 in

0 1 2 3 4 5 6 7 8 9

0 0.039 0.079 0.118 0.157 0.197 0.236 0.276 0.315 0.354

10 0.394 0.433 0.472 0.512 0.551 0.591 0.630 0.669 0.709 0.748
20 0.787 0.827 0.866 0.906 0.945 0.984 1.024 1.063 1.102 1.142
30 1.181 1.220 1.260 1.299 1.339 1.378 1.417 1.457 1.496 1.536
40 1.575 1.614 1.654 1.693 1.732 1.772 1.811 1.850 1.890 1.929
Ϳ
50 1.969 2.008 2.047 2.087 2.126 2.165 2.205 2.244 2.283 2.323
ͽ
60 2.362 2.402 2.441 2.480 2.520 2.559 2.598 2.638 2.677 2.717
70 2.756 2.795 2.835 2.874 2.913 2.953 2.992 3.032 3.071 3.110
80 3.150 3.189 3.228 3.268 3.307 3.346 3.386 3.425 3.465 3.504
90 3.543 3.583 3.622 3.661 3.701 3.740 3.780 3.819 3.858 3.898

0-3
Millimeters to inches 1mm = 0.03937in

0 1 2 3 4 5 6 7 8 9

0 0.039 0.079 0.118 0.157 0.197 0.236 0.276 0.315 0.354

10 0.394 0.433 0.472 0.512 0.551 0.591 0.630 0.669 0.709 0.748
20 0.787 0.827 0.866 0.906 0.945 0.984 1.024 1.063 1.102 1.142
30 1.181 1.220 1.260 1.299 1.339 1.378 1.417 1.457 1.496 1.536
40 1.575 1.614 1.654 1.693 1.732 1.772 1.811 1.850 1.890 1.929

50 1.969 2.008 2.047 2.087 2.126 2.165 2.205 2.244 2.283 2.323
60 2.362 2.402 2.441 2.480 2.520 2.559 2.598 2.638 2.677 2.717
70 2.756 2.795 2.835 2.874 2.913 2.953 2.992 3.032 3.071 3.110
80 3.150 3.189 3.228 3.268 3.307 3.346 3.386 3.425 3.465 3.504
90 3.543 3.583 3.622 3.661 3.701 3.740 3.780 3.819 3.858 3.898

Kilogram to Pound 1kg = 2.2046lb

0 1 2 3 4 5 6 7 8 9

0 2.20 4.41 6.61 8.82 11.02 13.23 15.43 17.64 19.84

10 22.05 24.25 26.46 28.66 30.86 33.07 35.27 37.48 39.68 41.89
20 44.09 46.30 48.50 50.71 51.91 55.12 57.32 59.5. 61.73 63.93
30 66.14 68.34 70.55 72.75 74.96 77.16 79.37 81.57 83.78 85.98
40 88.18 90.39 92.59 94.80 97.00 99.21 101.41 103.62 105.82 108.03

50 110.23 112.44 114.64 116.85 119.05 121.25 123.46 125.66 127.87 130.07
60 132.28 134.48 136.69 138.89 141.10 143.30 145.51 147.71 149.91 152.12
70 154.32 156.53 158.73 160.94 163.14 165.35 167.55 169.76 171.96 174.17
80 176.37 178.57 180.78 182.98 185.19 187.39 189.60 191.80 194.01 196.21
90 198.42 200.62 202.83 205.03 207.24 209.44 211.64 213.85 216.05 218.26

0-4
Liter to U.S. Gallon 1˶ = 0.2642 U.S.Gal

0 1 2 3 4 5 6 7 8 9

0 0.264 0.528 0.793 1.057 1.321 1.585 1.849 2.113 2.378

10 2.642 2.906 3.170 3.434 3.698 3.963 4.227 4.491 4.755 5.019
20 5.283 5.548 5.812 6.6076 6.340 6.604 6.869 7.133 7.397 7.661
30 7.925 8.189 8.454 8.718 8.982 9.246 9.510 9.774 10.039 10.303
40 10.567 10.831 11.095 11.359 11.624 11.888 12.152 12.416 12.680 12.944

50 13.209 13.473 13.737 14.001 14.265 14.529 14.795 15.058 15.322 15.586
60 15.850 16.115 16.379 16.643 16.907 17.171 17.435 17.700 17.964 18.228
70 18.492 18.756 19.020 19.285 19.549 19.813 20.077 20.341 20.605 20.870
80 21.134 21.398 21.662 21.926 22.190 22.455 22.719 22.983 23.247 23.511
90 23.775 24.040 24.304 24.568 24.832 25.096 25.631 25.625 25.889 26.153

Liter to U.K. Gallon 1˶ = 0.21997 U.K.Gal

0 1 2 3 4 5 6 7 8 9

0 0.220 0.440 0.660 0.880 1.100 1.320 1.540 1.760 1.980

10 2.200 2.420 2.640 2.860 3.080 3.300 3.520 3.740 3.950 4.179
20 4.399 4.619 4.839 5.059 5.279 5.499 5.719 5.939 6.159 6.379
30 6.599 6.819 7.039 7.259 7.479 7.969 7.919 8.139 8.359 8.579
40 8.799 9.019 9.239 9.459 9.679 9.899 10.119 10.339 10.559 10.778

50 10.998 11.281 11.438 11.658 11.878 12.098 12.318 12.528 12.758 12.978
60 13.198 13.418 13.638 13.858 14.078 14.298 14.518 14.738 14.958 15.178
70 15.398 15.618 15.838 16.058 16.278 16.498 16.718 16.938 17.158 17.378
80 17.598 17.818 18.037 18.257 18.477 18.697 18.917 19.137 19.357 19.577
90 19.797 20.017 20.237 20.457 20.677 20.897 21.117 21.337 21.557 21.777

0-5
kgfÂm to lbf
kgf lbfÂftft 1kgfÂm = 7.233lbfÂft

0 1 2 3 4 5 6 7 8 9

7.2 14.5 21.7 28.9 36.2 43.4 50.6 57.9 65.1

10 72.3 79.6 86.8 94.0 101.3 108.5 115.7 123.0 130.2 137.4
20 144.7 151.9 159.1 166.4 173.6 180.8 188.1 195.3 202.5 209.8
30 217.0 224.2 231.5 238.7 245.9 253.2 260.4 267.6 274.9 282.1
40 289.3 396.6 303.8 311.0 318.3 325.5 332.7 340.0 347.2 354.4

50 361.7 368.9 376.1 383.4 390.6 397.8 405.1 412.3 419.5 426.8
60 434.0 441.2 448.5 455.7 462.9 470.2 477.4 484.6 491.8 499.1
70 506.3 513.5 520.8 528.0 535.2 542.5 549.7 556.9 564.2 571.4
80 578.6 585.9 593.1 600.3 607.6 614.8 622.0 629.3 636.5 643.7
90 651.0 658.2 665.4 672.7 679.9 687.1 694.4 701.6 708.8 716.1

100 723.3 730.5 737.8 745.0 752.2 759.5 766.7 773.9 781.2 788.4
110 795.6 802.9 810.1 817.3 824.6 831.8 839.0 846.3 853.5 860.7
120 868.0 875.2 882.4 889.7 896.9 904.1 911.4 918.6 925.8 933.1
130 940.3 947.5 954.8 962.0 969.2 976.5 983.7 990.9 998.2 10005.4
140 1012.6 1019.9 1027.1 1034.3 1041.5 1048.8 1056.0 1063.2 1070.5 1077.7

150 1084.9 1092.2 1099.4 1106.6 1113.9 1121.1 1128.3 1135.6 1142.8 1150.0
160 1157.3 1164.5 1171.7 1179.0 1186.2 1193.4 1200.7 1207.9 1215.1 1222.4
170 1129.6 1236.8 1244.1 1251.3 1258.5 1265.8 1273.0 1280.1 1287.5 1294.7
180 1301.9 1309.2 1316.4 1323.6 1330.9 1338.1 1345.3 1352.6 1359.8 1367.0
190 1374.3 1381.5 1388.7 1396.0 1403.2 1410.4 1417.7 1424.9 1432.1 1439.4

0-6
kgf/cm2 to lbf/in2 1kgf / cm2 = 14.2233lbf / in2

0 1 2 3 4 5 6 7 8 9

14.2 28.4 42.7 56.9 71.1 85.3 99.6 113.8 128.0

10 142.2 156.5 170.7 184.9 199.1 213.4 227.6 241.8 256.0 270.2
20 284.5 298.7 312.9 327.1 341.4 355.6 369.8 384.0 398.3 412.5
30 426.7 440.9 455.1 469.4 483.6 497.8 512.0 526.3 540.5 554.7
40 568.9 583.2 597.4 611.6 625.8 640.1 654.3 668.5 682.7 696.9

50 711.2 725.4 739.6 753.8 768.1 782.3 796.5 810.7 825.0 839.2
60 853.4 867.6 881.8 896.1 910.3 924.5 938.7 953.0 967.2 981.4
70 995.6 1010 1024 1038 1053 1067 1081 1095 1109 1124
80 1138 1152 1166 1181 1195 1209 1223 1237 1252 1266
90 1280 1294 1309 1323 1337 1351 1365 1380 1394 1408

100 1422 1437 1451 1465 1479 1493 1508 1522 1536 1550
110 1565 1579 1593 1607 1621 1636 1650 1664 1678 1693
120 1707 1721 1735 1749 1764 1778 1792 1806 1821 1835
130 1849 2863 1877 1892 1906 1920 1934 1949 1963 1977
140 1991 2005 2020 2034 2048 2062 2077 2091 2105 2119

150 2134 2148 2162 2176 2190 2205 2219 2233 2247 2262
160 2276 2290 2304 2318 2333 2347 2361 2375 2389 2404
170 2418 2432 2446 2460 2475 2489 2503 2518 2532 2546
180 2560 2574 2589 5603 2617 2631 2646 2660 2674 2688

200 2845 2859 2873 2887 2901 2916 2930 2944 2958 2973
210 2987 3001 3015 3030 3044 3058 3072 3086 3101 3115
220 3129 3143 3158 3172 3186 3200 3214 3229 3243 3257
230 3271 3286 3300 3314 3328 3343 3357 3371 3385 3399
240 3414 3428 3442 3456 3470 3485 3499 3513 3527 3542

0-7
TEMPERATURE
Fahrenheit-Centigrade Conversion.
A simple way to convert a fahrenheit temperature reading into a centigrade temperature reading or vice verse
is to enter the accompanying table in the center or boldface column of figures.
These figures refer to the temperature in either Fahrenheit or Centigrade degrees.
If it is desired to convert from Fahrenheit to Centigrade degrees, consider the center column as a table of
Fahrenheit temperatures and read the corresponding Centigrade temperature in the column at the left.
If it is desired to convert from Centigrade to Fahrenheit degrees, consider the center column as a table of
Centigrade values, and read the corresponding Fahrenheit temperature on the right.

˚C ˚F ˚C ˚F ˚C ˚F ˚C ˚F
-40.4 -40 -40.0 -11.7 11 51.8 7.8 46 114.8 27.2 81 117.8
-37.2 -35 -31.0 -11.1 12 53.6 8.3 47 116.6 27.8 82 179.6
-34.4 -30 -22.0 -10.6 13 55.4 8.9 48 118.4 28.3 83 181.4
-31.7 -25 -13.0 -10.0 14 57.2 9.4 49 120.2 28.9 84 183.2
-28.9 -20 -4.0 -9.4 15 59.0 10.0 50 122.0 29.4 85 185.0

-28.3 -19 -2.2 -8.9 16 60.8 10.6 51 123.8 30.0 86 186.8

-27.8 -18 -0.4 -8.3 17 62.6 11.1 52 125.6 30.6 87 188.6
-27.2 -17 1.4 -7.8 18 64.4 11.7 53 127.4 31.1 88 190.4
-26.7 -16 3.2 -6.7 20 68.0 12.8 55 131.0 32.2 90 194.0
-26.1 -15 5.0 -6.7 20 68.0 12.8 55 131.0 32.2 90 194.0

-25.6 -14 6.8 -6.1 21 69.8 13.3 56 132.8 32.8 91 195.8

-25.0 -13 8.6 -5.6 22 71.6 13.9 57 134.6 33.3 92 197.6
-24.4 -12 10.4 -5.0 23 73.4 14.4 58 136.4 33.9 93 199.4
-23.9 -11 12.2 -4.4 24 75.2 15.0 59 138.2 34.4 94 201.2
-23.3 -10 14.0 -3.9 25 77.0 15.6 60 140.0 35.0 95 203.0

-22.8 -9 15.8 -3.3 26 78.8 16.1 61 141.8 35.6 96 204.8

-22.2 -8 17.6 -2.8 27 80.6 16.7 62 143.6 36.1 97 206.6
-21.7 -7 19.4 -2.2 28 82.4 17.2 63 145.4 36.7 98 208.4
-21.1 -6 21.2 -1.7 29 84.2 17.8 64 147.2 37.2 99 210.2
-20.6 -5 23.0 -1.1 35 95.0 21.1 70 158.0 51.7 125 257.0

-20.0 -4 24.8 -0.6 31 87.8 18.9 66 150.8 40.6 105 221.0

-19.4 -3 26.6 0 32 89.6 19.4 67 152.6 43.3 110 230.0
-18.9 -2 28.4 0.6 33 91.4 20.0 68 154.4 46.1 115 239.0
-18.3 -1 30.2 1.1 34 93.2 20.6 69 156.2 48.9 120 248.0
-17.8 0 32.0 1.7 35 95.0 21.1 70 158.0 51.7 125 257.0

-17.2 1 33.8 2.2 36 96.8 21.7 71 159.8 54.4 130 266.0

-16.7 2 35.6 2.8 37 98.6 22.2 72 161.6 57.2 135 275.0
-16.1 3 37.4 3.3 38 100.4 22.8 73 163.4 60.0 140 284.0
-15.6 4 39.2 3.9 39 102.2 23.3 74 165.2 62.7 145 293.0
-15.0 5 41.0 4.4 40 104.0 23.9 75 167.0 65.6 150 302.0

-14.4 6 42.8 5.0 41 105.8 24.4 76 168.8 68.3 155 311.0

-13.9 7 44.6 5.6 42 107.6 25.0 77 170.6 71.1 160 320.0
-13.3 8 46.4 6.1 43 109.4 25.6 78 172.4 73.9 165 329.0
-12.8 9 48.2 6.7 44 111.2 26.1 79 174.2 76.7 170 338.0
-12.2 10 50.0 7.2 45 113.0 26.7 80 176.0 79.4 172 347.0

0-8
 SECTION 1 GENERAL

Group 1 Safety Hints --------------------------------------------------------------------------------------------------------1-1

Group 2 Specifications -----------------------------------------------------------------------------------------------------1-10
Group 3 Operational Checkout Record Sheet ---------------------------------------------------------------1-25
 SECTION 1 GENERAL
GROUP 1 SAFETY HINTS

FOLLOW SAFE PROCEDURE

Unsafe wor k practices are dangerous.
Understand service procedure before doing
work; Do not attempt shortcuts.

WEAR PROTECTIVE CLOTHING

Wear close fitting clothing and safety equipment
appropriate to the job.

73031GE01

WARN OTHERS OF SERVICE WORK

Unexpected machine movement can cause
serious injury.
Before performing any work on the wheel load-
WARN
er, attach a ÖDo Do Not Operate
Operate× tag on the
DO
right side controller lever. NOT
OPERATE

75791GE01

USE HANDHOLDS AND STEPS

Falling is one of the major causes of personal inju-
ry.
When you get on and off the machine, always
maintain a three point contact with the steps and
handrails and face the machine. Do not use any
controls as handholds.
Never jump on or off the machine. Never mount or
dismount a moving machine. 73032E01

Be careful of slippery conditions on platforms,

steps, and handrails when leaving the machine.

1-1
PREPARE FOR EMERGENCIES
Be prepared if a fire starts.
Keep a first aid kit and fire extinguisher handy.
Keep emergency numbers for doctors,
ambulance ser vice, hospital, and fire
department near your telephone.

73031GE03

WORK IN CLEAN AREA

Before starting a job :
 Clean work area and machine.
 Make sure you have all necessary tools to do
your job.
 Have the right parts on hand.
 Read all instructions thoroughly; Do not
attempt shortcuts.
73031GE26

PROTECT AGAINST FLYING DEBRIS

Guard against injury from flying pieces of metal
or debris; Wear goggles or safety glasses.

73031GE04

PROTECT AGAINST NOISE

Prolonged exposure to loud noise can cause
impairment or loss of hearing.
Wear a suitable hearing protective device such
as earmuffs or earplugs to protect against
objectionable or uncomfortable loud noises.

73031GE05

1-2
PARK MACHINE SAFELY
Before working on the machine:
 Park machine on a level surface.
 Lower bucket to the ground.
 Turn key switch to OFF to stop engine.
Remove key from switch.
 Move pilot control shutoff lever to locked
position.
 Allow engine to cool. 73031GE23

SUPPORT MACHINE PROPERLY

Always lower the attachment or implement to
the ground before you work on the machine. If
you must work on a lifted machine or attachment,
securely support the machine or attachment.
Do not support the machine on cinder blocks,
hollow tiles, or props that may crumble under
continuous load.
Do not work under a machine that is supported
solely by a jack. Follow recommended
procedures in this manual. 73031GE06

SERVICE COOLING SYSTEM SAFELY

Explosive release of fluids from pressurized
cooling system can cause serious burns.
Shut off engine. Only remove filler cap when
cool enough to touch with bare hands.

73031GE07

HANDLE FLUIDS SAFELY-AVOID FIRES

Handle fuel with care; It is highly flammable.
Do not refuel the machine while smoking or
when near open flame or sparks. Always stop
engine before refueling machine.
Fill fuel tank outdoors.

73031GE08

1-3
Store flammable fluids away from fire hazards.
Do not incinerate or puncture pressurized
containers.
Make sure machine is clean of trash,
grease, and debris.
Do not store oily rags ; They can ignite and
burn spontaneously.

73031GE09

BEWARE OF EXHAUST FUMES

Prevent asphyxiation. Engine exhaust fumes
can cause sickness or death.
If you must operate in a building, be positive
there is adequate ventilation. Either use an
exhaust pipe extension to remove the exhaust
fumes or open doors and windows to bring
enough outside air into the area.

REMOVE PAINT BEFORE WELDING OR

HEATING
Avoid potentially toxic fumes and dust.
Hazardous fumes can be generated when paint
is heated by welding, soldering, or using a torch.
Do all work outside or in a well ventilated area.
Dispose of paint and solvent properly.
Remove paint before welding or heating:
 If you sand or grind paint, avoid breathing the
dust. Wear an approved respirator.
 If you use solvent or paint stripper, remove
stripper with soap and water before welding.
Remove solvent or paint stripper containers
and other flammable material from area.
Allow fumes to disperse at least 15 minutes
before welding or heating. 73031GE10

1-4
ILLUMINATE WORK AREA SAFELY
Illuminate your work area adequately but safely.
Use a portable safety light for working inside or
under the machine. Make sure the bulb is
enclosed by a wire cage. The hot filament of an
accidentally broken bulb can ignite spilled fuel
or oil.

73031GE11

SERVICE MACHINE SAFELY

Tie long hair behind your head. Do not wear a
necktie, scarf, loose clothing or necklace when
you work near machine tools or moving parts.
If these items were to get caught, severe injury
could result.
Remove rings and other jewelry to prevent
electrical shorts and entanglement in moving
parts. 73031GE12

STAY CLEAR OF MOVING PARTS

Entanglements in moving parts can cause
serious injury.
To prevent accidents, use care when working
around rotating parts.

73031GE13

1-5
AVOID HIGH PRESSURE FLUIDS
Escaping fluid under pressure can penetrate the
skin causing serious injury.
Avoid the hazard by relieving pressure before
disconnecting hydraulic or other lines. Tighten
all connections before applying pressure.
Search for leaks with a piece of cardboard.
Protect hands and body from high pressure
73031GE14
fluids.
If an accident occurs, see a doctor immediately.
Any fluid injected into the skin must be
surgically removed within a few hours or
gangrene may result.

73031GE15

AVOID HEATING NEAR PRESSURIZED

FLUID LINES
Flammable spray can be generated by heating
near pressurized fluid lines, resulting in severe
burns to yourself and bystanders. Do not heat
by welding, soldering, or using a torch near
pressurized fluid lines or other flammable
materials.
Pressurized lines can be accidentally cut when
heat goes beyond the immediate flame area.
Install fire resisting guards to protect hoses or 73031GE16

other materials.

PREVENT BATTERY EXPLOSIONS

Keep sparks, lighted matches, and flame away
from the top of battery. Battery gas can
explode.
Never check battery charge by placing a metal
object across the posts. Use a volt-meter or
hydrometer.
Do not charge a frozen battery; It may explode.
73031GE17
Warm battery to 16˚C (60˚F).

1-6
PREVENT ACID BURNS
Sulfuric acid in battery electrolyte is poisonous. It
is strong enough to burn skin, eat holes in
clothing, and cause blindness if splashed into
eyes.
1. Avoid the hazard by:
2. Filling batteries in a well-ventilated area.
3. Wearing eye protection and rubber gloves.
Avoiding breathing fumes when electrolyte
is added.
4. Avoiding spilling of dripping electrolyte.
5. Use proper jump start procedure.
1. If you spill acid on yourself:
2. Flush your skin with water.
Apply baking soda or lime to help neutralize
the acid.
3. Flush your eyes with water for 10-15 minutes.
Get medical attention immediately.
1. If acid is swallowed:
2. Drink large amounts of water or milk.
Then drink milk of magnesia, beaten eggs,
or vegetable oil.
73031GE18
3. Get medical attention immediately.

USE TOOLS PROPERLY

Use tools appropriate to the work. Makeshift
tools, parts, and procedures can create safety
hazards.
Use power tools only to loosen threaded tools
and fasteners.
For loosening and tightening hardware, use the
correct size tools. Avoid bodily injury caused by
73031GE19
slipping wrenches.
Use only recommended replacement parts.
(See Parts catalogue.)

1-7
SERVICE TIRES SAFELY
Explosive separation of a tire and rim parts can
cause serious injury or death.
Do not attempt to mount a tire unless you have the
proper equipment and experience to perform the job.
Always maintain the correct tire pressure. Do not
inflate the tires above the recommended pressure.
Never weld or heat a wheel and tire assembly.
The heat can cause an increase in air pressure
resulting in a tire explosion.
Welding can structurally weaken or deform the
wheel.
When inflating tires, use a clip-on chuck and
extension hose long enough to allow you to stand
to one side and not in front of or over the tire
assembly. Use a safety cage if available.
Check wheels for low pressure, cuts, bubbles, 73031GE24

damaged rims or missing lug bolts and nuts.

USE PROPER LIFTING EQUIPMENT

Lifting heavy components incorrectly can cause
severe injury or machine damage.
Follow recommended procedure for removal and
installation of components in the manual.

73031GE25

DISPOSE OF FLUIDS PROPERLY

Improperly disposing of fluids can harm the
environment and ecology. Before draining any
fluids, find out the proper way to dispose of waste
from your local environmental agency.
Use proper containers when draining fluids. Do
not use food or beverage containers that may
mislead someone into drinking from them.
73031GE20
DO NOT pour oil into the ground, down a drain, or
into a stream, pond, or lake. Observe relevant
environmental protection regulations when
disposing of oil, fuel, coolant, brake fluid, filters,
batteries, and other harmful waste.

1-8
REPLACE SAFETY SIGNS
Replace missing or damaged safety signs.
See the machine operator's manual for correct
safety sign placement.

73031GE21

LIVE WITH SAFETY

Before returning machine to customer, make
sure machine is functioning properly, especially
the safety systems. Install all guards and
shields.

KEEP ROPS INSTALLED PROPERLY

Make certain all parts are reinstalled correctly if
the roll-over protective structure (ROPS) is
loosened or removed for any reason. Tighten
mounting bolts to proper torque.
The protection offered by ROPS will be
impaired if ROPS is subjected to structural
damage, is involved in an overturn incident, or is
in any way altered by welding, bending, drilling,
or cutting. A damaged ROPS should be 73031GE22
replaced, not reused.

1-9
GROUP 2 SPECIFICATION

1. MAJOR COMPONENT

Bucket Tire Head light Hydraulic tank Air cleaner Battery

Boom Bucket cylinder Main control valve Step Radiator Counterweight

Bucket link Bell crank Steering cylinder Cab Precleaner Muffler Engine

Front axle Boom cylinder Main pump Transmission Rear axle Fuel tank

78092SE01

1-10
2. SPECIFICATIONS
1) WITH BOLT-ON CUTTING EDGE TYPE BUCKET (HL780-9)

6295
B

F
I
H

4560

C
G
K
40

D
6
748 430
5 E
A
78092SE03

Description Unit Specification

Operating weight kg (lb) 30000 (66100)
Struck 4.6 (6.0)
Bucket capacity m3 (yd3)
Heaped 5.4 (7.1)
Overall length A 9630 (31' 7")
Overall width B 3450 (11' 4")
Overall height C 3865 (12' 8")
Ground clearance D 495 (1' 7")
Wheelbase E mm (ft-in) 3700 (12' 2")
Tread F 2440 (8' 0")
Dump clearance at 45˚ G 3300 (10' 10")
Dump reach (full lift) H 1430 (4' 8")
Width over tires I 3220 (10' 7")
Dump angle J 47
degree (˚)
Roll back angle (carry position) K 48
Lift (with load) 6.0
Cycle time Dump (with load) sec 1.4
Lower (empty) 3.7
Maximum travel speed km/hr (mph) 36.5
Braking distance 12 (39' 4")
m (ft-in)
Minimum turning radius (center of outside tire) 6.43 (21' 1")
Gradeability degree (˚) 30
First gear 6.1 (3.8)
Second gear 11.5 (7.2)
Forward
Third gear 18.0 (11.2)
Travel speed Fourth gear km/hr (mph) 36.5 (22.7)
First gear 6.1 (3.8)
Reverse Second gear 11.5 (7.2)
Third gear 25.0 (15.6)

1-11
 WITH BOLT-ON CUTTING EDGE TYPE BUCKET (HL780XTD-9)

6670
B

F
I
H

4935

C
G
K
40

D
64
765 30
5 E
A

78092SE03-1

Description Unit Specification

Operating weight kg (lb) 30800 (67900)
Struck 4.6 (6.0)
Bucket capacity m3 (yd3)
Heaped 5.4 (7.1)
Overall length A 10060 (33' 0")
Overall width B 3450 (11' 4")
Overall height C 3865 (12' 8")
Ground clearance D 485 (1' 7")
Wheelbase E mm (ft-in) 3700 (12' 2")
Tread F 2440 (8' 0")
Dump clearance at 45˚ G 3670 (12' 0")
Dump reach (full lift) H 1480 (4' 10")
Width over tires I 3220 (10' 7")
Dump angle J 47
degree (˚)
Roll back angle (carry position) K 49
Lift (with load) 6.0
Cycle time Dump (with load) sec 1.4
Lower (empty) 3.7
Maximum travel speed km/hr (mph) 36.5
Braking distance 12 (39' 4")
m (ft-in)
Minimum turning radius (center of outside tire) 6.43 (21' 1")
Gradeability degree (˚) 30
First gear 6.1 (3.8)
Second gear 11.5 (7.2)
Forward
Third gear 18.0 (11.2)
Travel speed Fourth gear km/hr (mph) 36.5 (22.7)
First gear 6.1 (3.8)
Reverse Second gear 11.5 (7.2)
Third gear 25.0 (15.6)

1-12
 2) WITH TOOTH TYPE BUCKET (HL780-9)

6295
J
B

F
I
H

4560

C
G
K
40

D
64
757 30
0 E
A

78092SE04

Description Unit Specification

Operating weight kg (lb) 30000 (66100)
Struck 4.4 (5.8)
Bucket capacity m3 (yd3)
Heaped 5.2 (6.8)
Overall length A 9820 (32' 3")
Overall width B 3500 (11' 6")
Overall height C 3865 (12' 8")
Ground clearance D 495 (1' 7")
Wheelbase E mm (ft-in) 3700 (12' 2")
Tread F 2440 (8' 0")
Dump clearance at 45˚ G 3145 (10' 4")
Dump reach (full lift) H 1560 (5' 1")
Width over tires I 3220 (10' 7")
Dump angle J 47
degree (˚)
Roll back angle (carry position) K 48
Lift (with load) 6.0
Cycle time Dump (with load) sec 1.4
Lower (empty) 3.7
Maximum travel speed km/hr (mph) 36.5
Braking distance 12 (39' 4")
m (ft-in)
Minimum turning radius (center of outside tire) 6.43 (21' 1")
Gradeability degree (˚) 30
First gear 6.1 (3.8)
Second gear 11.5 (7.2)
Forward
Third gear 18.0 (11.2)
Travel speed Fourth gear km/hr (mph) 36.5 (22.7)
First gear 6.1 (3.8)
Reverse Second gear 11.5 (7.2)
Third gear 25.0 (15.6)

1-13
 WITH TOOTH TYPE BUCKET (HL780XTD-9)

6670
J
B

F
I

4935
H

C
G
K
40

D
64
774 30
0 E
A

78092SE04-1

Description Unit Specification

Operating weight kg (lb) 30800 (67900)
Struck 4.4 (5.8)
Bucket capacity m3 (yd3)
Heaped 5.2 (6.8)
Overall length A 10250 (33' 8")
Overall width B 3500 (11' 6")
Overall height C 3865 (12' 8")
Ground clearance D 495 (1' 7")
Wheelbase E mm (ft-in) 3700 (12' 2")
Tread F 2440 (8' 0")
Dump clearance at 45˚ G 3520 (11' 7")
Dump reach (full lift) H 1600 (5' 3")
Width over tires I 3220 (10' 7")
Dump angle J 47
degree (˚)
Roll back angle (carry position) K 49
Lift (with load) 6.0
Cycle time Dump (with load) sec 1.4
Lower (empty) 3.7
Maximum travel speed km/hr (mph) 36.5
Braking distance 12 (39' 4")
m (ft-in)
Minimum turning radius (center of outside tire) 6.43 (21' 1")
Gradeability degree (˚) 30
First gear 6.1 (3.8)
Second gear 11.5 (7.2)
Forward
Third gear 18.0 (11.2)
Travel speed Fourth gear km/hr (mph) 36.5 (22.7)
First gear 6.1 (3.8)
Reverse Second gear 11.5 (7.2)
Third gear 25.0 (15.6)

1-14
3. WEIGHT

Item kg lb
Front frame assembly 2712 5980
Rear frame assembly 3595 7930
Front fender (LH & RH) 48 106
Counterweight 1300 2870
Additional counterweight (HL780XTD-9) 552 1220
Cab assembly 1050 2320
Engine assembly 984 2170
Transmission assembly 835 1840
Drive shaft (front) 25 55
Drive shaft (center) 48 106
Drive shaft (rear) 30 66
Front axle (include differential) 1814 4000
Rear axle (include differential) 1805 3980
Tire (29.5-25, 22PR, L3) 430 948
Hydraulic tank assembly 270 595
Fuel tank assembly 483 1060
Main pump 45 99
Steering pump 45 99
Fan & brake pump assembly 7 15
Main control valve (3 spool) 104 229
Flow amplifier 29 64
HL780-9 2050 4520
Boom assembly
HL780XTD-9 2260 4980
Bell crank assembly 282 620
Bucket link 60 132
5.4 m3 bucket, with bolt on cutting edge 2750 6060
5.2 m3 bucket, with tooth 2585 2430
Boom cylinder assembly (2EA) 290 639
Bucket cylinder assembly (2EA) 130 287
Steering cylinder assembly (2EA) 60 132
Seat 40 88
Battery 55 121

1-15
4. SPECIFICATION FOR MAJOR COMPONENTS
1) ENGINE
Item Specification
Model Cummins QSM 11
Type 4-cycle turbocharged, charge air cooled diesel engine
Control type Electronic control
Cooling method Water cooling
Number of cylinders and arrangement 6 cylinders, in-line
Firing order 1-5-3-6-2-4
Combustion chamber type Direct injection type
Cylinder bore × stroke 125×147 mm (4.92"×5.79")
Piston displacement 10800 cc (659 cu in)
Compression ratio 16.3 : 1
Rated gross horse power 353 ps at 2000 rpm
Maximum gross torque at 1400 rpm 171 kgf·m (1235 lbf·ft)
Engine oil quantity 38ℓ (10 U.S. gal)
Wet weight 984 kg (2170 lb)
High idling speed 2130 ± 50 rpm
Low idling speed 800 ± 50 rpm
Rated fuel consumption 162 g/ps·hr
Starting motor Delco Remy 42MT (24 V)
Alternator Delco Remy 22SI (24 V - 70 Amp)
Battery 2×12V×220Ah

1-16
 2) MAIN PUMP
Specification
Item
Steering pump Loader pump
Type Variable double piston pump
Capacity 110 cc/rev 100 cc/rev
Maximum operating pressure 280 kgf/cm2 (3980 psi)
Rated oil quantity 220ℓ/min (58.1 U.S.gpm) 200ℓ/min (52.8 U.S.gpm)
Rated speed 2000 rpm

3) FAN + BRAKE PUMP

Specification
Item
Fan pump Brake pump
Type Fixed displacement tandem gear pump
Capacity 26.7 cc/rev 26.4 cc/rev
Maximum operating pressure 120 kgf/cm2 (1710 psi) 150 kgf/cm2 (2130 psi)
Rated oil quantity 53.4ℓ/min (14.1 U.S.gpm) 52.8ℓ/min (13.9 U.S.gpm)
Rated speed 2000 rpm

4) MAIN CONTROL VALVE

Item Specification
Type 2 spool
Operating method Hydraulic pilot assist
Main relief valve pressure 280 kgf/cm2 (3980 psi)
Overload relief valve pressure 340 kgf/cm2 (4840 psi)
Overload relief valve pressure (dump) 310 kgf/cm2 (4410 psi)

5) REMOTE CONTROL VALVE

Item Specification
Type Pressure reducing type
Minimum 5 kgf/cm2 (71 psi)
Operating
Maximum 30 kgf/cm2 (427 psi)
Single operation angle degree 17

1-17
 6) CYLINDER
Item Specification
Boom cylinder Bore dia×Rod dia×Stroke Ø180×Ø105×863 mm
Bucket cylinder Bore dia×Rod dia×Stroke Ø140×Ø 75×575 mm
Steering cylinder Bore dia×Rod dia×Stroke Ø105×Ø 55×480 mm

7) DYNAMIC POWER TRANSMISSION DEVICES

Item Specification
Model ZF 4WG310
Converter Single-stage, double-phase
Type
Transmission Full-automatic power shift
Converter stall ratio 2.987 : 1
Transmission
Gear shift Forward fourth gear, reverse third gear
Electrical single lever type, kick-down system,
Control Automatic kick down from 2nd to 1st gear
FNR Switch on joystick lever (option)
Pump rated flow 105ℓ/min (27.7 U.S.gpm) at 2000 rpm
Drive devices 4-wheel drive
Axle Front Front fixed location
Rear Oscillation 13˚ of center pin-loaded
Wheels Tires 29.5-25, 22PR (L3)
Travel Four-wheel, wet-disc type, full hydraulic
Brakes
Parking Spring applied, hydraulic released brake
Type Full hydraulic, articulated
Steering
Steering angle 40˚ to both right and left angle, respectively

1-18
5. TIGHTENING TORQUE OF MAJOR COMPONENT
Torque
No. Descriptions Bolt size
kgf·m lbf·ft
1 Engine mounting bolt, nut (rubber, 4EA) M24×3.0 100 ± 15.0 723 ± 108
2 Engine mounling bolt (fly wheel housing, 8EA) M16×2.0 19.4 ± 3.0 140 ± 21.7
3 Engine Engine mounting bolt (gear housing, 6EA) M10×1.5 4.6 ± 0.7 33.3 ± 5.1
4 Radiator mounting bolt M20×2.5 57.9 ± 8.7 419 ± 62.9
5 Fuel tank mounting bolt, nut M16×2.0 29.7 ± 4.5 215 ± 32.5
6 Main pump housing mounting bolt M14×2.0 19.6 ± 2.9 142 ± 21.0
7 Steering pump housing mounting bolt M14×2.0 19.6 ± 2.9 142 ± 21.0
8 Main control valve mounting bolt M12×1.75 12.8 ± 3.0 92.6 ± 21.7
9 Steering unit mounting bolt M10×1.5 6.9 ± 1.4 49.9 ± 10.1
10 Flow amplifier mounting bolt M10×1.5 6.9 ± 1.4 49.9 ± 10.1
Hydraulic
11 Brake valve mounting bolt M8×1.25 2.5 ± 0.5 18.1 ± 3.6
system
12 Cut-off valve mounting bolt M12×1.75 12.3 ± 2.0 89.0 ± 14
13 Remote control lever mounting bolt M6×1.0 1.1 ± 0.2 8.0 ± 1.4
14 Stop valve M10×1.5 6.9 ± 1.4 50 ± 10.1
15 Safety valve M10×1.5 6.9 ± 1.4 50 ± 10.1
16 Hydraulic oil tank mounting bolt M20×2.5 57.9 ± 8.7 419 ± 62.9
17 Transmission bolt, nut (rubber, 4EA) M24×3.0 100 ± 15.0 723 ± 108
18 Transmission bolt (bracket, converter side) M16×2.0 18.4 ± 2.0 133 ± 14.5
19 Power train Front axle mounting bolt, nut M36×3.0 270 ± 30 1950 ± 217
20 system Rear axle support mounting bolt, nut M36×3.0 270 ± 30 1950 ± 217
21 Tire mounting nut M22×1.5 79 ± 2.5 571 ± 18
22 Drive shaft joint mounting bolt, nut M20×2.5 57.9 ± 8.7 419 ± 62.9
23 Counterweight mounting bolt M30×2.0 199 ± 30 1439 ± 217
24 Others Operator's seat mounting bolt M8×1.25 3.4 ± 0.8 24.6 ± 5
25 ROPS Cab mounting bolt (4EA) M20×2.5 58 ± 8.7 419 ± 63

1-19
6. TORQUE CHART

Use following table for unspecified torque.

1) BOLT AND NUT

(1) Coarse thread

8T 10T
Bolt size
kg·m lb·ft kg·m lb·ft
M 6×1.0 0.85 ~ 1.25 6.15 ~ 9.04 1.14 ~ 1.74 8.2 ~ 12.6
M 8×1.25 2.0 ~ 3.0 14.5 ~ 21.7 2.73 ~ 4.12 19.5 ~ 29.8
M10×1.5 4.0 ~ 6.0 28.9 ~ 43.4 5.5 ~ 8.3 39.8 ~ 60
M12×1.75 7.4 ~ 11.2 53.5 ~ 79.5 9.8 ~ 15.8 71 ~ 114
M14×2.0 12.2 ~ 16.6 88.2 ~ 120 16.7 ~ 22.5 121 ~ 167
M16×2.0 18.6 ~ 25.2 135 ~ 182 25.2 ~ 34.2 182 ~ 247
M18×2.5 25.8 ~ 35.0 187 ~ 253 35.1 ~ 47.5 254 ~ 343
M20×2.5 36.2 ~ 49.0 262 ~ 354 49.2 ~ 66.6 356 ~ 482
M22×2.5 48.3 ~ 63.3 350 ~ 457 65.8 ~ 98.0 476 ~ 709
M24×3.0 62.5 ~ 84.5 452 ~ 611 85.0 ~ 115 615 ~ 832
M30×3.0 124 ~ 168 898 ~ 1214 169 ~ 229 1223 ~ 1655
M36×4.0 174 ~ 236 1261 ~ 1703 250 ~ 310 1808 ~ 2242

(2) Fine thread

8T 10T
Bolt size
kg·m lb·ft kg·m lb·ft
M 8×1.0 2.17 ~ 3.37 15.7 ~ 24.3 3.04 ~ 4.44 22.0 ~ 32.0
M10×1.25 4.46 ~ 6.66 32.3 ~ 48.2 5.93 ~ 8.93 42.9 ~ 64.6
M12×1.25 7.78 ~ 11.58 76.3 ~ 83.7 10.6 ~ 16.0 76.6 ~ 115
M14×1.5 13.3 ~ 18.1 96.2 ~ 130 17.9 ~ 24.1 130 ~ 174
M16×1.5 19.9 ~ 26.9 144 ~ 194 26.6 ~ 36.0 193 ~ 260
M18×1.5 28.6 ~ 43.6 207 ~ 315 38.4 ~ 52.0 278 ~ 376
M20×1.5 40.0 ~ 54.0 289 ~ 390 53.4 ~ 72.2 386 ~ 522
M22×1.5 52.7 ~ 71.3 381 ~ 515 70.7 ~ 95.7 512 ~ 692
M24×2.0 67.9 ~ 91.9 491 ~ 664 90.9 ~ 123 658 ~ 890
M30×2.0 137 ~ 185 990 ~ 1338 182 ~ 248 1314 ~ 1795
M36×3.0 192 ~ 260 1389 ~ 1879 262 ~ 354 1893 ~ 2561

1-20
2) PIPE AND HOSE (FLARE type)
Thread size Width across flat (mm) kgf·m lbf·ft

1/4" 19 4 28.9
3/8" 22 5 36.2
1/2" 27 9.5 68.7
3/4" 36 18 130
1" 41 21 152
1-1/4" 50 35 253

3) PIPE AND HOSE (ORFS type)

Thread size Width across flat (mm) kgf·m lbf·ft

9/16-18 19 4 28.9
11/16-16 22 5 36.2
13/16-16 27 9.5 68.7
1-3/16-12 36 18 130
1-7/16-12 41 21 152
1-11/16-12 50 35 253

4) FITTING

Thread size Width across flat (mm) kgf·m lbf·ft

1/4" 19 4 28.9
3/8" 22 5 36.2
1/2" 27 9.5 68.7
3/4" 36 18 130
1" 41 21 152
1-1/4" 50 35 253

1-21
7. RECOMMENDED LUBRICANTS
Use only oils listed below or equivalent.
Do not mix different brand oil.
Ambient temperature C ( F)
Capacity
Service point Kind of fluid -20 -10 0 10 20 30 40
ℓ (U.S. gal)
(-4) (14) (32) (50) (68) (86) (104)

SAE 30

SAE 10W
Engine oil pan Engine oil 38 (10.0)
SAE 10W-30

SAE 15W-40

SAE 10W-30
Transmission Engine oil 43 (11.4)
SAE 15W-40

Front : 58 (15.3)
Axle UTTO Refer to below list
Rear : 58 (15.3)

ISO VG 32
Tank:
234 (61.8)
Hydraulic tank Hydraulic oil ISO VG 46
System:
344 (90.9)
ISO VG 68

ASTM D975 NO.1

Fuel tank Diesel fuel 450 (118.8)
ASTM D975 NO.2

NLGI NO.1
Fitting
Grease As required
(grease nipple) NLGI NO.2

Mixture of
antifreeze Ethylene glycol base permanent type
Radiator 65 (17.2)
and water
50 : 50

·SAE Society of Automotive Engineers ★ Recommended oil list

·API American Petroleum Institute - BP TERRAC SUPER TRANSMISSION 10W-30
·ISO International Organization for Standardization - CASTROL AGRI TRANS PLUS 10W-30
·NLGI National Lubricating Grease Institute - MOBILFLUID 426
·ASTM American Society of Testing and Material - SHELL DONAX TD 10W-30
·UTTO Universal Tractor Transmission Oil - TOTAL DYNATRANS MPV

1-22
 GROUP 3 OPERATIONAL CHECKOUT RECORD SHEET

ÂOwner 
ÂDate 
ÂHours 
ÂSerial No. 
ÂTechnician 

ö Use this sheet to record operational

checkout results.
Perform the operational check before
installing any test equipment. 78092GE01

OK NOT
Item Comments
OK

1. Monitor indicator and gauge checks (engine OFF)

 Hourmeter and gauge check □ □

 Battery check □ □
 Monitor indicator circuit check □ □
 Cluster turn signals and warning indicator check □ □

2. Transmission, axle and engine, neutral start

switch and reverse warning alarm switch checks

 Transmission control lever and neutral □ □

 Neutral start and reverse warning □ □
 Alarm circuit checks □ □

3. Monitor indicator and gauge checks (engine running)

 Monitor display and alternator output checks □ □

 Monitor bypass circuit and seat belt indicator check □ □
 Monitor primary and secondary level check □ □
 Transmission oil warm up procedure □ □
 Transmission temperature gauge check □ □

1-23
4. Brake system and clutch cut off checks

 Park brake capacity check □ □

 Park brake transmission lockout check □ □
 Service brake pump flow check □ □
 Service brake capacity check □ □
 Brake accumulator precharge check □ □
 Brake system leakage check □ □
 Service brake pedal check □ □
 Service and park brake system drag check □ □
 Clutch cut off check □ □

5. Driving checks

ÂTransmission oil warm up procedure □ □

ÂTransmission noise check □ □
ÂSpeedometer check □ □
ÂTransmission kick down system check □ □
Â1st, 2nd, 3rd and 4th speed clutch pack drag check □ □
ÂTransmission pressure, pump flow and leakage check □ □
ÂTransmission shift modulation check □ □
ÂTorque converter check □ □
ÂEngine power check □ □

6. Hydraulic system checks

ÂHydraulic system warm up procedure □ □

ÂHydraulic pump performance check □ □
ÂPilot control valve boom float check □ □
ÂBoom down solenoid valve check □ □
ÂControl valve lift check □ □
ÂBucket rollback circuit relief valve check □ □
ÂBucket dump circuit relief
Low pressure check □ □
High pressure check □ □
ÂBoom and bucket cylinder drift check □ □
ÂBoom down solenoid valve leakage check □ □
ÂPilot controller check □ □
ÂReturn to dig check □ □
ÂBoom height kickout check-if equipped □ □

1-24
7. Steering system checks

ÂSteering unit check □ □

ÂSteering system leakage check □ □
ÂSteering valve (EHPS)
Low check pressure □ □
High check pressure □ □

8. Accessory checks

ÂOperating lights check □ □

ÂWork light check □ □
ÂBrake light check □ □
ÂCab light check □ □
ÂHorn circuit check □ □
ÂWindshield washer and wiper check □ □
ÂDefroster blower check □ □
ÂHeater/Air conditioner blower check □ □
ÂHeater functional check □ □
ÂAir conditioner functional check □ □
ÂStart aid system check □ □

9. Cab components and vandal protection checks

ÂCab door latch check □ □

ÂCab door hold open latch check □ □
ÂCab door release button check □ □
ÂCab door lock check □ □
ÂCab door window check □ □
ÂCab window latch check □ □
ÂSteering column adjustment check □ □
ÂSeat and seat belt check □ □
ÂAir intake filter door check □ □
ÂEngine side panels check □ □
ÂRadiator cap access door check □ □
ÂFrame locking bar check □ □
ÂBoom lock check □ □
ÂService decal check □ □

1-25
 SECTION 2 ENGINE

Group 1 Structure and Function -------------------------------------------------------------------------------------- 2-1

Group 2 Fuel warmer system ------------------------------------------------------------------------------------------ 2-14
Group 3 Engine speed and Stall rpm ----------------------------------------------------------------------------- 2-15
Group 4 Fan drive circuit for cooling system ------------------------------------------------------------------ 2-16
 SECTION 2 ENGINE
GROUP 1 STRUCTURE AND FUNCTION

1. STRUCTURE

Engine coolant vent

Air intake manifold

Exhaust manifold

Corrosion resistor
Dipstick
Coolant inlet
Filler cap

Oil filter
Oil pan sump heater

Oil drain

Air intake connection

Lifting bracket Blowby measurement

Compressor
mounting location
Electronic control
module(ECM)
Flywheel
Fuel inlet to pump

Fuel filter
Engine support
Oil pan

Side oil drain

7807AEN01

 Direct 4-stroke, 6-cylinders, water-cooling and charge air cooled diesel engine in installed, cylinder
block and cylinder head are made of case iron and turbocharger is attached.

2-1
2. COMPONENTS
1) The ECM receives information from various
components in the QSM system.

2) The temperature sensors are a two-wire

type sensor with a 5 volt supply and signal
return. The ECM registors temperature
changes as the voltage drops across this
circuit.

3) The Coolant Temperature Sensor is

mounted in the thermostat housing. Its
input is required to properly control engine
timing, and to control the operation of the
fan clutch. This sensor also provides input
to the engine protection system.

4) The Intake Air Temperature Sensor is

mounted on the rear of the intake manifold.
Its input is required by the engine protection
system, as well as for engine control
purposes.

2-2
5) The Oil Temperature Sensor is mounted in
the main oil rifle. It provides input to the
engine protection system.

6) The Engine Position Sensor, or EPS, is a

magnetic pick-up type device that uses the
detection of 24 specially machined
surfaces, on the back side of the camshaft
gear, to monitor engine speed.
A unique "tooth" indicates number one
cylinder at top dead center compression
stroke, for injection timing purposes.

7) The pressure sensors are a three-wire type

sensor with a 5 volt supply, a signal wire,
and a return. Although pressure sensors
use an analog signal similar to the
temperature sensors, the electronics built
into the sensor require that separate signal
and return wires be used.

8) The oil Pressure Sensor is mounted in the

main oil rifle. Like the oil temperature
sensor, it provides input information to the
engine protection system.

2-3
9) The Boost Pressure Sensor is mounted
next to the intake manifold temperature
sensor. Its input is crucial to the precise
electronic control of fuel metering.

10) An Ambient Air Pressure sensor provides

altitude input information to the ECM for
altitude derate purposes.

11) The vehicle Control Data Link Connector

provides a means of connecting the QSM
system with other onboard microprocessor-
based systems, such as an anti-skid
braking system.
This connector, however, is not designed to
be used with a diagnostic tool such as
INSITE. INSITE and other diagnostic tools
should only be connected to the Service
Data Links located on the OEM Harness or
the Service Data Link mounted on the
engine next to the ECM.

2-4
12) Engines with QSM systems will have a
service data link mounted next to the ECM.
This additional data link was added
because new calibration procedures
require that the key switch must be off
during calibration transfer. But many
OEM harnesses have a small amount of
voltage across the data link connection
even with the key off.
The OEM harness data link can be used
for all service tool operations except
transferring calibrations. Only the engine-
mounted data link should be used for
calibration transfer.

13) A 21-pin OEM connector is part of the

Engine Harness. The keyswitch, diagnostic
switch, coolant level sensor, fan control
signals, and data link wires pass through
the Engine Har ness and the OEM
connections.

14) The throttle pedal assembly is supplied by

the OEM. This assembly includes a base
plate, dual return springs, idle validation
switch, foot pedal, wiring harness, and a
potentiometer, or "pot".
No mechanical linkage exists between the
foot pedal and the engine.

2-5
15) The potentiometer provides a DC voltage
signal propor tional to pedal angle
displacement.
The ECM sees this voltage signal as an
indication of throttle position.

16) The Idle Validation Switch provides

verification independent of throttle pot
movement that the pedal is, or is not, in the
idle position. This scheme allows the ECM
to detect potential throttle assembly
problems. The Idle Validation Switch can
be a separate mechanical or an integrated
switch with the potentiometer.

17) The tachometer output-signal connector

can provide the engine RPM signal to the
vehicle tachometer.

18) In this section we'll review the major

components of the QSM Hydromechanical
Subsystem.
The QSM system fuel supply pump is
mounted to the air compressor assembly
and, like the air compressor, is driven by
the engine through the accessory drive.

2-6
19) It's a gear-type pump, using one-and-a-
quarter-inch gears.
The pressure regulator is set at
approximately 150 psi.

20) The ECM is mounted on a cooling plate.

During engine operation, fuel circulates
through the one-pass unit, absorbing heat
generated by the ECM electronics.

21) The electronically controlled injector is

substantially different from standard PT
injectors. The most apparent difference is
the addition of a solenoid valve near the top
of the injector.
Controlled by the ECM, it determines the
amount of fuel metered, as well as injection
timing.

22) As mentioned earlier, the QSM injector

uses camshaft actuation to build adequate
pressure for injection.
 Lower Overhead Force and Cam Stress
Â
Improved Injection Train Component Life
Â
Shorter Heat Release during Combustion
Â
Lower Emissions
Â

Improved Fuel Economy

2-7
23) The QSM injector includes the top stop
shim; injector control valve; spring guide;
timing chamber; bias spring; metering
plunger; pressure relief valve; closed nozzle
subassembly, with its cup, needle valve and
return spring; metering check valve;
metering spill port; fuel drain passage; fuel
supply passage; timing plunger; bottom
stop shim; return spring; and the top stop
assembly.

24) To better understand the operation of the

injector, let's study a simplified version.
Here we can see the timing plunger, top
stop hardware, return spring, injector
control valve, metering spill port, pressure
relief valve, fuel supply passage, metering
check valve, closed-nozzle subassembly,
metering plunger, bias spring, timing spill
port, and the bottom stop shim.

25) At the start of metering, the metering

plunger and the timing plunger are at the
lower limits of their travel. The injector
control valve is closed.

26) As the camshaft rotates, the timing plunger

return spring forces the timing plunger
upward.
Fuel flows past the metering checkball and
into the metering chamber. This flow
continues as long as the timing plunger is
moving upward, and the injector control
valve is closed.
Supply pressure, acting on the bottom of
the metering piston, forces it to maintain
contact with the timing plunger.

2-8
27) The ECM determines the end of metering
by signaling the injector control valve to
open.

28) Fuel at supply pressure then flows into the

timing chamber, thereby stopping metering-
piston travel.
During this time, the bias spring ensuress
that the meter ing plunger remains
stationary, that it does not drift upward as
the timing plunger moves upward. This
same force against the metering plunger
results in enough fuel pressure below the
piston to keep the metering check ball
seated.
A precisely metered quantity of fuel is now
trapped in the metering chamber. This
determines the quantity of fuel that will be
injected.

29) The timing plunger continues to move

upward, and the timing chamber fills with
fuel.

2-9
30) Now the timing plunger begins its
downward travel. Initially, the injector
control valve remains open, allowing fuel to
flow from the timing chamber, through the
injector control valve, to the fuel supply
passage.

31) At the appropriate time, as determined by

the ECM, the injector control valve closes,
trapping fuel in the timing chamber. This
trapped fuel acts as a solid hydraulic link
between the timing plunger and metering
plunger.

32) As a result, the metering plunger is forced

to move down-ward with the timing plunger.
Because the fuel is trapped, the downward
force on the timing plunger is transferred to
the metering plunger, thereby increasing
pressure in the metering chamber.

33) When this pressure reaches approximately

5000 psi, the needle valve begins to be
forced upward.
Continued downward movement of the
timing plunger and metering plunger results
in steadily increasing fuel pressure. The
result is that fuel is forced past the needle
valve, through the spray holes, and into the
combustion chamber.

2-10
34) Injection continues until the spill passage of
the metering plunger passes the metering
spill port.
Metering-chamber pressure drops rapidly,
allowing the needle valve to close abruptly.
This action results in a positive end of
injection. The positive end of injection
prevents dribble, and results in cleaner
burning.
It is also at this point that the pressure relief
valve "pops off" thereby reducing the
effects of the high pressure "spike" that
occurs at the time of metering spill. The
relief valve passage connects to the fuel
drain line.

35) Immediately after the metering spill port is

opened, the upper edge of the metering
plunger passes the timing spill port.

36) This action allows the fuel in the timing

chamber to be spilled back to the fuel drain
as the timing plunger completes its
downward movement.
This completes the injection cycle.

2-11
37) To summarize QSM system operation, the
injector is camshaft-actuated to achieve
high pressures.

38) Opening the injector control valve

terminates metering, which results in a
precise amount of fuel to be injected.
Closing the injector control valve controls
the start of injection. This injection "timing"
can be varied over a wide range of values.

39) By varying the amount of time the injector

control valve remains open, and remains
closed, the ECM is able to maintain precise
and independent control of metering and
timing values. This process allows the
system to meet engine demands resulting
from a wide range of operating conditions.

40) When fuel pressure exceeds that of the

needle valve return spring, the needle valve
opens and injection begins.
Injection ends when the pressure drops to
less than this opening pressure.

2-12
41) The primary diagnostic tool for use with the
QSM system will be the INSITE computer
based diagnostic tool.
Echek and Compulink cartridges will be
available for use with QSM.

2-13
 GROUP 2 ENGINE SPEED & STALL RPM
1. TEST
TEST CONDITION
1) Normal temperature of the whole system
- Coolant : Approx 80˚C (176˚F)
- Hydraulic oil : 45 Ü 5˚C (113 Ü 10˚F)
- Transmission oil : 75 Ü 5˚C (167 Ü 10˚F)
2) Normal operating pressure : See page 6-58.
2. SPECIFICATION
SPECIFICATION
Engine speed, rpm
Remark
Low idle High idle Pump stall Converter stall Full stall
800Ü50 2130Ü50 2100Ü70 2030Ü70 1980Ü100

3. ENGINE
ENGINE RPM CHECK
Remark : If the checked data is not normal, it indicates that the related system is not working properly.
Therefore, it is required to check the related system pressure : See page 6-58.
1) Pump stall rpm
- Start the engine and raise the bucket
approx 45 cm (1.5 ft) as the figure.
- Press the accelerator pedal fully and
45cm

operate the bucket control lever to the

retract position fully.
- Check the engine rpm at the above
condition.
78092EG01

2) Convertor stall rpm

- Start the engine and lower the bucket on
OFF

the ground as the figure.

L

M H

- Set the clutch cut off mode switch at the Clutch cut off mode switch
OFF position.
- Press the brake pedal and accelerator
pedal fully.
- Shift the transmission lever to the 4th
forward position.
- Check the engine rpm at the above 78092EG02

condition.
3) Full stall rpm
- Start the engine and raise the bucket
OFF

approx 45 cm (1.5 ft) as the figure.

L

M H

- Set the clutch cut off mode switch at the Clutch cut off mode switch

OFF position.
- Press the brake pedal and accelerator
45cm

pedal fully .
- Shift the transmission lever to the 4th
forward position and operate the bucket
lever to the retract position fully. 78092EG03

- Check the engine rpm at the above

condition.
2-14
GROUP 3 F
FUEL
UEL WARMER SYSTEM

1. S
SPECIFICATION
PECIFICATION
1) Operating voltage : 24Ü4V
2) Power : 350Ü50W
3) Current : 15A

2. O
OPERATION
PERATION
1) T h e c u r r e n t o f f u e l w a r m e r s y s t e m i s Fuel warmer
automatically controlled without thermostat
according to fuel temperature.
2) At the first state, the 15A current flows to the fuel
warmer and engine may be started in 1~2 Prefilter
minutes.
3) If the fuel starts to flow, ceramic-disk in the fuel
warmer heater senses the fuel temperature to
reduce the current as low as 1.5A.
So, fuel is protected from overheating by this
2507A5MS12
mechanism.

3. E
ELECTRIC
LECTRIC CIRCUIT
CS-74 CS-74A CN-60
3R 3R 104 105
1 1
3R 3R 102 8W 111 106
2 2

1
2

MASTER SW CS-74B CR-1

CN-6
CN-94 24 BATTERY
611 W BATTERY RY
BATT (+) 4 25
611A W 610 W
BATT (+) 3 26
27
TO STARTER
BATT (-) 2
G 55
BATT (-) 1
ECM EARTH
(BATTERY(-) TERMINAL)
MCU
5W 113
AC COMP. OFF SIG_REVERSE FAN

SPARE_LOW_ENGINE OIL LOW

AC CONDENSOR FAN SIGNAL
SPARE_DIGITAL INPUT_LOW

BUCKET POSITION SENSOR

BLOWER RUN SIGNAL_DINP
SPARE_DIGITAL INPUT_LOW

BOOM POSITION SENSOR

CASSETTE/ROOM LAMP

SERVICE SOCKET 1

SERVICE SOCKET 2
CLUSTER 24V BATTERY
START KEY SWITCH

FAN REVERSE, ATT.

SEAT HEAT/AIR-RIDE
AIR-CON/HEATER 2

JOYSTICK-DETENT
MCU 24V BATTERY
ECM 24V BATTERY
TCU 24V BATTERY

JOYSTIC_SWITCH

SPARE_HIGH SOURCE
PARK, PILOT CUT

RIDE CONTROL
NC_SPARE 10A
NC_SPARE 15A
TURN LAMP

FUEL WARMER
WIPER INT SIG
PRE-HEAT

CAN2 LOW
WIPER

WASH SIG
CAN2 HI
20A

30A
10A
10A
10A
20A
10A
10A
15A

20A
20A
20A
20A
20A
10A
30A
20A
10A
10A
5A

A38
B14

B15
A16
A24

B40
B30
A05
A18
A08
A23
A31

A35

A26
20
18
19
12
13

16
17
14
15
11
10
6
3
4
1
2

7
5

8
9

L 380

CN-37 CN-36 CN-58B

CN-5
CR-35 26
86 30 87a 113 W
27
B G01 113 W
85 28
Gr 550
87 MCU POWER IG 29
RW 531
86 30
85 87 87a R 530
30 31
POWER RY 42 CN-13 CN-96
LW 381 382B L 384 384 L
CR-25 33 1 B
382A L 384A G53 B
86 30 87a 34 2 A
B G01A
85 35 12
Y 620 FUEL WARMER
87 ECM POWER IG 32 3
RW 531
86 37 8
85 87 87a R 530B
30 7
ECM POWER RY 6
5
LW 381
Y 370A

Y 370B
H BR ACC ST C

6
Y 370
L 380

5 CS-2
6
3 5
CR-46

CR-36

2
87

30
87a
85

86

4
B

1
1
5

3
2
4

RW 531
4 3
85 8787a
0, I

1 5 4

1
H 0 I II

86 30

2 3

GOr 534
2

START SWITCH FUEL WARMER RY PREHEAT RY

75792EG04

2-15
GROUP 4 FAN DRIVE CIRCUIT FOR COOLING SYSTEM

1. REQUIRED TOOL
Item Spec
Pressure gauge 200 kgf/cm2 (2840 psi)
rpm gauge 200~2000 rpm
Wrench 13 mm
Tool
Hex. wrench 3 mm

2. PRESSURE CHECK AND ADJUSTMENT

1) Specification
Cooling fan speed (rpm) Pressure [kgf/cm2 (psi)]
950±10 115±5 (1640±70)

2) Check point
Harness connector
(CN-154) Relief valve

Relief valve Harness connector

(CN-154)
Uni-dictional Bi-dictional
WTHCS01

3) Pressure check
(1) Install the pressure gauge to fan drive motor ( )
(2) Disconnect CN-154.
(3) Check the fan drive motor pressure at high engine rpm.
(4) Check the cooling fan speed using rpm gauge at high engine rpm.

4) Adjustment
(1) Turn the adjusting screw clockwise to
increase the cooling fan rpm and relief
pressure.
(2) Tur n the adjusting screw counter
clockwise to decrease the cooling fan rpm
and relief pressure.
Adjusting screw

WTHCS02

2-16
 SECTION 3 POWER TRAIN SYSTEM

Group 1 Structure and Function -------------------------------------------------------------------------------------- 3-1

Group 2 Operational Checks and Troubleshooting -------------------------------------------------------- 3-58
Group 3 Tests and Adjustments -------------------------------------------------------------------------------------- 3-69
Group 4 Disassembly and Assembly ------------------------------------------------------------------------------ 3-71
 SECTION 3 POWER TRAIN SYSTEM
GROUP 1 STRUCTURE AND FUNCTION

1. POWER TRAIN COMPONENT OVERVIEW

Transmission Upper drive shaft Engine

Front axle Front drive shaft Rear drive shaft Rear axle
Center drive shaft

78093PT01

The power train consists of the following components:

·Transmission
·Front, center, rear and upper drive shafts
·Front and rear axles
Engine power is transmitted to the transmission through the torque converter.
The transmission is a hydraulically engaged four speed forward, three speed reverse countershaft type
power shift transmission. A calliper-disc type parking brake is located on the front axle.
The transmission outputs through universal joints to three drive shaft assemblies. The front drive shaft
is a telescoping shaft which drives the front axle. The front axle is mounted directly to the loader frame.
The front axle is equipped with limited slip differential.
The rear axle is mounted on an oscillating pivot. The rear axle is equipped with limited slip differential.
The power transmitted to front axle and rear axle is reduced by the pinion gear and ring gear of
differential. It then passes from the differential to the sun gear shaft (axle shaft) of final drive.
The power of the sun gear is reduced by a planetary mechanism and is transmitted through the
planetary hub to the wheel.

3-1
 HYDRAULIC CIRCUIT

KR K4 K1 K3 KV K2

P1 F 60 P2 E 55 P3 D 56 P4 C 58 P5 B 53 P6 A 57

B D B D B D B D B D B D

Y1 RTT Y2 RTT Y3 RTT Y4 RTT Y5 RTT Y6 RTT

Pressure
Temp reducing
sensor valve
9+0.5 bar
System
pressure
Valve block control circuit valve
16+2 bar

Converter
Filter
Relief
valve
11+2 bar Filter pressure
differential valve
Oil cooler Bcak
pressure
valve Pump
Bypass 4.3+3 bar
valve 16+2 bar
3 bar

Oil sump
Lubrication Main oil circuit

7707APT09

NFS Follow-on slide P3 Proportional valve clutch K1

D Oscillation damper P4 Proportional valve clutch K3
B Orifice P5 Proportional valve clutch KV
P1 Proportional valve clutch KR P6 Proportional valve clutch K2
P2 Proportional valve clutch K4 Y1~Y6 Pressure regulator valve with filter

Current
Forward Reverse Positions
Engaged No. of the
Speed Neutral on the
clutch measuring
1 2 3 4 1 2 3 valve block
points
Y1 X X X KR F 55
Y2 X K4 E 60
Y3 X X K1 D 56
Y4 X X X K3 C 58
Y5 X X X KV B 53
Y6 X X K2 A 57
Engaged
K1,KV KV,K2 KV,K3 K4,K3 KR,K1 KR,K2 KR, K3 - - -
clutch
X : Pressure regulator under voltage

3-2
2. TORQUE CONVERTER

5 1 2 3 4

7704PT03

1 Turbine 3 Pump 5 Input shaft

2 Stator 4 Transmission pump

The converter is working according to the Trilok-system, i.e. it assumes at high turbine speed the
characteristics, and with it the favorable efficiency of a fluid clutch.
The converter will be defined according to the engine power so that the most favorable operating
conditions for each installation case are given.
The Torque converter is composed of 3 main components :
Pump wheel - turbine wheel - stator (reaction member)
These 3 impeller wheels are arranged in such a ring-shape system that the fluid is streaming through
the circuit components in the indicated order.
Pressure oil is constantly streaming out of the transmission pump through the converter. In this way,
the converter can fulfill its task to multiply the torque of the engine, and at the same time, the heat
created in the converter is dissipated through the escaping oil.
The oil, escaping out of the pump wheel, enters the turbine wheel and is there inversed in the direction
of flow.
According to the rate of inversion, the turbine wheel and with it also the output shaft, receive a more or
less high reaction moment. The stator (reaction member), following the turbine, has the task to inverse
again the oil which is escaping out of the turbine and to delivery it under the suitable discharge direction
to the pump wheel.
Due to the inversion, the stator receives a reaction moment.
The relation turbine moment/pump moment is called torque conversion. This is the higher the greater
the speed difference of pump wheel and turbine wheel will be.
Therefore, the maximum conversion is created at standing turbine wheel.
With increasing output speed, the torque conversion is decreasing. The adoption of the output speed to
a certain required output moment is infinitely variable and automatically achieved by the torque
converter.

3-3
If the turbine speed is reaching about 80% of the pump speed, the conversion becomes 1.0 i.e. the
turbine moment becomes equal to that of the pump moment.
From this point on, the converter is working similar to a fluid clutch.
A stator freewheel serves to improve the efficiency in the upper driving range, it is backing up in the
conversion range the moment upon the housing, and is released in the coupling range.
In this way, the stator can rotate freely.

Function of a hydrodynamic torque converter (schematic view)

TP = Torque of the pump wheel

TT = Torque of the turbine wheel
TR = Torque of the reaction member (stator)

Pump wheel TR

Turbine wheel
From the engine
TT

TP

To the gearbox

Starting
condition 1 1.5 Reaction member 2.5
nT = 0
(Stator) Machine
stopped
Intermediate
condition 1 <1.5 <2.5 nT < n engine

Condition shortly
before the converter 1 1 nT = 0.8n engine
0
clutch is closed.
Turbine wheel is running with
about the same speed as
pump wheel.

3-4(770-3)

3-4
3. TRANSMISSION
1) LAYOUT

1 2 3 4

KV K1

KR K2

K4 K3
10

13 12 11

78093PT03

1 Torque converter 8 Clutch axle-KR/K2

2 Breather 9 Clutch axle-K4/K3
3 Electro-hydraulic shift control 10 Parking brake
4 2nd power take off 11 Output shaft
5 Transmission pump 12 Output flange (converter side)
6 1st power take off 13 Countershaft
7 Clutch axle-KV/K1

3-5
2) INSTALLATION VIEW

1 2 7 8 9 10 18 20 17 14 15 16 24 19

3 45 6 11 2' 12 13 23 22 21

78093PT05

1 Breather 12 Cover
2 Transmission suspension M16 13 Output flange
2' Transmission suspension M20 14 Pressure oil line clutch K2
3 Attachment possibility for an oil filler 15 Pressure oil line clutch KR
tube with oil dipstick. 16 Pressure oil line clutch KV
4 Output flange 17 1st power take off
5 Oil drain plug 18 2nd power take off
6 Coarse filter 19 Pressure oil line clutch K3
7 Input flange 20 Pressure oil line clutch K1
8 Converter bell 21 Lubricating oil line S2 clutch K4/K3
9 Lifting lug 22 Lubricating oil line S1 clutch KR/K2
10 Electrohydraulic shift controller 23 Parking brake
11 Gearbox housing 24 Pressure oil line clutch K4

3-6
3) OPERATION OF TRANSMISSION
(1) Forward
① Forward 1st
In 1st forward, forward clutch and 1st clutch are engaged.
Forward clutch and 1st clutch are actuated by the hydraulic pressure applied to the clutch piston.

INPUT

KV K1

KR K2

K4 K3

OUTPUT OUTPUT

78093PT07

3-7
② Forward 2nd
In 2nd forward, forward clutch and 2nd clutch are engaged.
forward clutch and 2nd clutch are actuated by the hydraulic pressure applied to the clutch piston.

INPUT
KV

K1

KR K2

K4 K3

OUTPUT OUTPUT

78093PT08

3-8
③ Forward 3rd
In 3rd forward, forward clutch and K3 (3rd) clutch are engage.
Forward clutch and 3rd clutch are actuated by the hydraulic pressure applied to the clutch piston.

INPUT

KV K1

KR K2

K4 K3

OUTPUT OUTPUT

78093PT09

3-9
④ Forward 4th
In 4th forward, 4th clutch and 3rd clutch are engaged.
4th clutch and 3rd clutch are actuated by the hydraulic pressure applied to the clutch piston.

INPUT

KV K1

KR K2

K4 K3

OUTPUT OUTPUT

78093PT10

3-10
(2) Reverse
① Reverse 1st
In 1st reverse, reverse clutch and 1st clutch are engaged.
reverse clutch and 1st clutch are actuated by the hydraulic pressure applied to the clutch piston.

INPUT

KV K1

KR K2

K4 K3

OUTPUT OUTPUT

78093PT11

3-11
② Reverse 2nd
In 2nd reverse, reverse clutch and 2nd clutch are engaged.
reverse clutch and 2nd clutch are actuated by the hydraulic pressure applied to the clutch piston.

INPUT

KV K1

KR K2

K4 K3

OUTPUT OUTPUT

78093PT12

3-12
③ Reverse 3rd
In 3rd reverse, reverse clutch and 3rd clutch are engaged.
reverse clutch and 3rd clutch are actuated by the hydraulic pressure applied to the clutch piston.

INPUT

KV K1

KR K2

K4 K3

OUTPUT OUTPUT

78093PT13

3-13
4) ELECTRO-HYDRAULIC SHIFT CONTROL WITH PROPORTIONAL VALVE

2 1 3

A A
Y6 Y1

Y5 Y2

B
Y4 Y3

3 6

2 6 1 4 11 9 10

Y5

SECTION A-A SECTION B-B

8 7
73033CV01

1 Pressure reducing valve (9bar) 7 Intermediate plate

2 Main pressure valve (16+2bar) 8 Duct plate
3 Housing 9 Vibration damper
4 Cable harness 10 Follow-on slide
5 Cover 11 Pressure regulator
6 Valve block

Transmission control, see schedule of measuring points, hydraulic schematic and electro-hydraulic
control unit at page 3-2, 3-14 and 3-69.
The six clutches of the transmission are selected via the 6 proportional valves P1 to P6. The
proportional valve (pressure regulator unit) consists of pressure regulator (e.g. Y6), follow-on slide
and vibration damper.
The control pressure of 9 bar for the actuation of the follow-on slides is created by the pressure
reducing valve. The pressure oil (16+2bar) is directed via the follow-on slide to the respective
clutch.

3-14
 Due to the direct proportional selection with separated pressure modulation for each clutch, the
pressures to the clutches, which are engaged in the gear change, will be controlled. In this way, a
hydraulic intersection of the clutches to be engaged and disengaged becomes possible.
This is creating spontaneous shiftings without traction force interruption.
At the shifting, the following criteria will be considered:
- Speed of engine, turbine, central gear train and output.
- Transmission temperature.
- Shifting mode (up-, down-, reverse shifting and speed engagement out of neutral).
- Load condition (full and part load, traction, overrun inclusive consideration of load cycles during
the shifting).
The main pressure valve is limiting the maximum control pressure to 16+2 bar and releases the
main stream to the converter and lubricating circuit.
In the inlet to the converter, a convert safety valve is installed which protects the converter from
high internal pressures (opening pressure 11bar).
Within the converter, the oil serves to transmit the power according to the well-known
hydrodynamic principle (see torque converter, page 3-3).
To avoid cavitation, the converter must be always completely filled with oil.
This is achieved by a converter pressure holding valve, rear-mounted to the converter, with an
opening pressure of at least 5bar.
The oil, escaping out of the converter, is directed to a oil cooler.
The oil is directed from the oil cooler to the transmission and there to the lubricating oil circuit so
that all lubricating points are supplied with cooled oil.
In the electro-hydraulic control unit there are 6 pressure regulators installed.

5) GEAR SELECTOR (DW-3)

The gear selector is designed for the
mounting on the left side of the steering
column. By a rotative motion, the positions F
1

(speeds) 1 to 4 are selected by tilting the 4

2
3
N

R
lever, the driving direction Forward
(F)-Neutral (N)-Reverse (R).
The gear selector is also available with
integrated kickdown push button.
For the protection from unintended start off,
a neutral interlock is installed :
Position N - Gear selector lever blocked in N D

this position.
Position D - Driving. 73033TM17

3-15
6) ELECTRIC CONTROL UNIT
(1) Complete system
8

5 10

9
4
3 11

6
12

13
14

8
1
16
15
7

17

78093PT23

1 Gear selector (DW-3)

2 Monitor
3 Clutch cut off mode switch
4 Transmission shift mode switch
5 Control unit (EST-37)
6 Filter
7 Power supply connection
8 Kickdown switch
9 Wiring
10 Cable to speed sensor output and speedometer
11 Cable to temperature measuring point behind the converter
12 Cable to plug connection on the electrohydraulic control unit
13 Cable to inductive transmitter speed engine
14 Cable to inductive transmitter speed turbine
15 Cable to inductive transmitter speed central gear train
16 Transmission
17 Brake pressure sensor / Load sensor
(2) Description of the basic functions
The powershift transmission will be equipped with the electronic transmission control unit (EST-
37), developed for it.
The system is processing the desire of the driver according to the following criteria.

3-16
 ·Protection from operating errors as far as necessary, is possible via electronic protection
(programming).
·Protection from over-speeds (On the basis of engine and turbine speed).
·Automatic reversing (Driving speed-dependent).
·Pressure cut-off possible (Disconnecting of the drive train for maximum power on the power
take-off).
·Change-over possibility for Auto-/Manual mode.
·Kick down functions possible.
(3) Driving and shifting
- Neutral position :
Neutral position will be selected via the controller.
After the ignition is switched on, the electronics remains in the waiting state. By the position
NEUTRAL of the controller, resp. by pressing the pushbutton NEUTRAL, the EST-37A becomes
ready for operation.
Now, a gear can be engaged.
- Starting :
The starting of the engine has always to be carried out in the NEUTRAL POSITION of the
controller.
For safety reasons it is to recommend to brake the machine securely in position with the parking
brake prior to start the engine.
After the starting of the engine and the preselection of the driving direction and the gear, the
machine can be set in motion by acceleration.
At the start off, the converter takes over the function of a master clutch.
On a level road it is possible to start off also in higher gears.
- Upshifting under load
Upshifting under load will be then realized if the machine can still accelerate by it.
- Downshifting under load
Downshifting under load will be realized if more traction force is needed.
- Upshifting in overrunning condition
In the overrunning mode, the upshifting will be suppressed by accelerator pedal idling position, if
the speed of the machine on a downgrade should not be further increased.
- Downshifting in overrunning condition
Downshiftings in overrunning mode will be then carried out if the machine should be retarded.
If the machine will be stopped and is standing with running engine and engaged transmission,
the engine cannot be stalled. On a level and horizontal roadway it is possible that the machine
begins to crawl, because the engine is creating at idling speed a slight drag torque via the
converter.
It is convenient to brake the machine at every stop securely in position with the parking brake.
At longer stops, the controller has to be shifted to the NEUTRAL POSITION.
At the start off, the parking brake has to be released. We know from experience that at a
converter transmission it might not immediately be noted to have forgotten this quite normal
operating step because a converter, due to its high ratio, can easily overcome the braking
torque of the parking brake.

3-17
 Temperature increases in the converter oil as well as overheated brakes will be the
consequences to be find out later.
Neutral position of the selector switch at higher machine speeds (above stepping speed) is not
admissible.
Either a suitable gear is to be shifted immediately, or the machine must be stopped at once.
(4) Independent calibration of the shifting elements (AEB)
The AEB has the task to compensate tolerances (plate clearance and pressure level) which are
influencing the filling procedure of the clutches. For each clutch, the correct filling parameters are
determined in one test cycle for :
·Period of the quick-filling time
·Level of the filling compensating pressure
The filling parameters are stored, together with the AEB-program and the driving program in the
transmission electronics. Because the electronics will be separately supplied, the AEB-cycle
must be started only after the installation of both components in the machine, thus ensuring the
correct mating (Transmission and electronics).
※ It is imperative, to respect the following test conditions :
- Shifting position neutral
- Engine in idling speed
- Parking brake actuated
- Transmission in operating temperature
※ After a replacement of the transmission, the electrohydraulic control or the TCU in the machine,
the AEB-cycle must be as well carried out again.
The AEB-cylcle continues for about 3 to 4 minutes. The determined filling parameters are stored
in the EEProm of the electronics. In this way, the error message F6 shown on the display will be
cancelled also at non-performed AEB.
(5) Pressure cut-off
In order to provide the full engine power for the hydraulic system, the control can be enlarged for
the function of a pressure cut-off in the 1st and 2nd speed. In this way, the pressure in the
powershift clutches will be cut-off, and the torque transmission in the drive train will be eliminated
by it. This function will be released at the actuation of a switch, arranged on the brake pedal.
For a soft restart, the pressure will be build-up via a freely programmable characteristic line.

3-18
4. FAULT CODE
1) MACHINE FAULT CODE
HCESPN FMI Description
Hydraulic oil temperature sensor circuit - Voltage above normal, or shorted to high source (or
3
101 open circuit)
4 Hydraulic oil temperature sensor circuit - Voltage below normal, or shorted to low source
5 Engine cooling fan EPPR valve circuit - Current below normal, or open circuit
145
6 Engine cooling fan EPPR valve bircuit - Current above normal
Boom up lever detent solenoid circuit - Voltage below normal, or shorted to low source (or
4
172 open circuit)
6 Boom up lever detent solenoid circuit - Current above normal
Boom down lever detent solenoid circuit - Voltage below normal, or shorted to low source (or
4
173 open circuit)
6 Boom down lever detent solenoid circuit - Current above normal
Bucket lever detent solenoid circuit - Voltage below normal, or shorted to low source (or open
4
174 circuit)
6 Bucket lever detent solenoid circuit - Current above normal
Engine cooling fan reverse solenoid circuit - Voltage below normal, or shorted to low source (or
4
181 open circuit)
6 Engine cooling fan reverse solenoid circuit - Current above normal
Engine cooling fan reverse driving status signal circuit - Voltage below normal, or shorted to
4
183 low source (or open circuit)
6 Engine cooling fan reverse driving status signal circuit - Current above normal
Emergency steering pump relay circuit - Voltage below normal, or shorted to low source (or
4
187 open circuit)
6 Emergency steering pump relay circuit – Current above normal
0 Steering main pump pressure sensor data above normal range (or open circuit)
1 Steering main pump pressure sensor data below normal range
202
2 Steering main pump pressure sensor data error
4 Steering main pump pressure sensor circuit - Voltage below normal, or shorted to low source
0 Emergency steering pump pressure sensor data above normal range (or open circuit)
1 Emergency steering pump pressure sensor data below normal range
203 2 Emergency steering pump pressure sensor data error
Emergency steering pump pressure sensor circuit - Voltage below normal, or shorted to low
4
source
0 Boom cylinder pressure sensor data above normal range (or open circuit)
1 Boom cylinder pressure sensor data below normal range
204
2 Boom cylinder pressure sensor data error
4 Boom cylinder pressure sensor circuit - Voltage below normal, or shorted to low source
0 Bucket cylinder pressure sensor data above normal range (or open circuit)
1 Bucket cylinder pressure sensor data below normal tange
205
2 Bucket cylinder pressure sensor data error
4 Bucket cylinder pressure sensor circuit - Voltage below normal, or shorted to low source

3-19
HCESPN FMI Description
3 Fuel level sensor circuit - Voltage above normal, or shorted to high source (or open circuit)
301
4 Fuel level sensor circuit - Voltage below normal, or shorted to low source
Engine coolant temperature sensor circuit - Voltage above normal, or shorted to high source
3
304 (or open circuit)
4 Engine coolant temperature sensor circuit - Voltage below normal, or shorted to low source
310 8 Engine speed signal error – Abnormal frequency or pulse width
318 8 Engine cooling fan speed signal error – Abnormal frequency or pulse width
4 Engine preheat relay circuit – Voltage below normal, or shorted to low source (or open circuit)
322
6 Engine preheat relay circuit - Current above normal
4 Fuel warmer relay circuit - Voltage below normal, or shorted to low source (or open circuit)
325
6 Fuel warmer relay circuit – Current above normal
4 Anti-restart relay circuit - Voltage below normal, or shorted to low source (or open circuit)
327
6 Anti-restart relay circuit – Current above normal
Engine power mode selector circuit – Voltage above normal, or shorted to high source (or
3
346 open circuit)
4 Engine power mode selector circuit – Voltage below normal, or shorted to low source
0 Brake oil pressure sensor data above normal range (or open circuit)
1 Brake oil pressure sensor data below normal range
503
2 Brake oil pressure sensor data error
4 Brake oil pressure sensor circuit – Voltage below normal, or shorted to Low Source
0 Parking oil pressure sensor data above normal range (or open circuit)
1 Parking oil pressure sensor data below normal range
507
2 Parking oil pressure sensor data error
4 Parking oil pressure sensor circuit - Voltage below normal, or shorted to low source
Clutch cut off mode selector circuit – Voltage above normal, or shorted to high source (or
3
551 open circuit)
4 Clutch cut off mode selector circuit – Voltage below normal, or shorted to low source
Transmission shift mode selector circuit – Voltage above normal, or shorted to high source (or
3
552 open circuit)
4 Transmission shift mode selector circuit – Voltage below normal, or shorted to low source
0 Differential lock pressure sensor data above normal range (or open circuit)
1 Differential lock pressure sensor data below normal range
558
2 Differential lock pressure sensor data error
4 Differential lock pressure sensor circuit - Voltage below normal, or shorted to low source
701 4 Hourmeter circuit - Voltage below normal, or shorted to low source
0 Battery voltage high
705
1 Battery voltage low

3-20
HCESPN FMI Description
707 1 Alternator node I voltage low (or open circuit)
3 Buzzer circuit - Voltage above normal, or shorted to high source
723
4 Buzzer circuit - Voltage below normal, or shorted to low source (or open circuit)
4 Wiper relay circuit - Voltage below normal, or shorted to low source (or open circuit)
727
6 Wiper relay circuit – Current above normal
Boom position sensor signal circuit – Voltage above normal, or shorted to high
3
728 source (or open circuit)
4 Boom position sensor signal circuit – Voltage below normal, or shorted to low source
Bucket position sensor signal circuit – Voltage above normal, or shorted to high
3
source (or open circuit)
729
Bucket position sensor signal circuit – Voltage below normal, or shorted to low
4
source
730 19 APTC heater PWM output duty operation error
830 12 MCU internal memory error
840 2 Cluster communication error
841 2 ECM communication error
842 2 TCU communication error
843 2 APTC communication error
844 2 Monitor communication error
850 2 RMCU communication error

3-21
2) ENGINE FAULT CODES
Fault code
J1939 SPN Reason Effect (only when fault code is active)
J1939 FMI
Engine control module critical internal failure - Possible no noticeable performance effects,
111
Bad intelligent device or component. Error engine dying, or hard starting.
629
internal to the ECM related to memory hardware
12
failures or internal ECM voltage supply circuits.
Engine magnetic crankshaft speed/position lost Fueling to injectors is disabled and the engine
115 both of two signals - Data erratic, intermittent, or can not be started.
612 incorrect. The ECM has detected that the
2 primary engine speed sensor and the backup
engine speed sensor signals are reversed.
Intake manifold 1 pressure sensor circuit - Engine power derate.
122 Voltage above normal, or shorted to high source.
102 High signal voltage detected at the intake
3 manifold pressure circuit.
Intake manifold 1 pressure sensor circuit - Engine power derate.
123 Voltage below normal, or shorted to low Source.
102 Low signal voltage or open circuit detected at the
4 intake manifold pressure circuit.
Intake manifold 1 pressure - Data valid but above Engine power derate.
124 normal operational range - Moderately severe
102 level. Intake manifold pressure has exceeded the
16 maximum limit for the given engine rating.
Accelerator pedal or lever position sensor 1 Severe derate in power output of the engine.
131 circuit - Voltage above normal, or shorted to high Limp home power only.
91 source. High voltage detected at accelerator
3 pedal position circuit.
Accelerator pedal or lever position sensor 1 Severe derate in power output of the engine.
132 circuit - Voltage below normal, or shorted to low Limp home power only.
91 source. Low voltage detected at accelerator
4 pedal position signal circuit.
Remote accelerator pedal or lever position Remote accelerator will not operate. Remote
133 sensor 1 circuit - Voltage above normal, or accelerator position will be set to zero percent.
974 shorted to high source. High voltage detected at
3 remote accelerator pedal position circuit.
Remote accelerator pedal or lever position Remote accelerator will not operate. Remote
134 sensor 1 circuit - Voltage below normal, or accelerator position will be set to zero percent.
974 shorted to low source. Low voltage detected at
4 remote accelerator pedal position signal circuit.
Engine oil rifle pressure 1 sensor circuit - Voltage None on performance. No engine protection
135 above normal, or shorted to high source. High for oil pressure.
100 signal voltage detected at the engine oil pressure
3 circuit.
Engine oil rifle pressure 1 sensor circuit - Voltage None on performance. No engine protection
141 below normal, or shorted to low source. Low for oil pressure.
100 signal voltage detected at engine oil pressure
4 circuit.
143 Engine oil rifle pressure - Data valid but below None on performance.
100 normal operational range - Moderately severe
18 level.
Engine coolant temperature 1 sensor circuit - Possible white smoke. Fan will stay ON if
144
Voltage above normal, or shorted to high source. controlled by ECM. No engine protection for
110
High signal voltage or open circuit detected at engine coolant temperature.
3
engine coolant temperature circuit.

3-22
Fault code
J1939 SPN Reason Effect (only when fault code is active)
J1939 FMI
Engine Coolant Temperature 1 Sensor Circuit - Possible white smoke. Fan will stay ON if
145
Voltage Below Normal, or Shorted to Low controlled by ECM. No engine protection for
110
Source. Low signal voltage detected at engine engine coolant temperature.
4
coolant temperature circuit.
Engine Coolant Temperature - Data Valid but Progressive power derate increasing in
146 Above Normal Operational Range - Moderately severity from time of alert.
110 Severe Level. Engine coolant temperature signal
16 indicates engine coolant temperature is above
engine protection warning limit.
Accelerator Pedal or Lever Position 1 Sensor Severe derate in power output of the engine.
Circuit Frequency - Data Valid but Below Normal Limp home power only.
147
Operational Range - Most Severe Level. A
91
frequency of less than 100 Hz has been
1
detected at the frequency throttle input to the
ECM.
Accelerator Pedal or Lever Position Sensor 1 - Severe derate in power output of the engine.
148 Data Valid but Above Normal Operational Limp home power only.
91 Range - Most Severe Level. A frequency of
0 more than 1500 Hz has been detected at the
frequency throttle input to the ECM.
Engine Coolant Temperature - Data Valid but Progressive power derate increasing in
151 Above Normal Operational Range - Most severity from time of alert. If Engine Protection
110 Severe Level. Engine coolant temperature signal Shutdown feature is enabled, engine will shut
0 indicates engine coolant temperature above down 30 seconds after Red Stop Lamp starts
engine protection critical limit. flashing.
Intake Manifold 1 Temperature Sensor Circuit - Possible white smoke. Fan will stay ON if
153 Voltage Above Normal, or Shorted to High controlled by ECM. No engine protection for
105 Source. High signal voltage detected at intake intake manifold air temperature.
3 manifold air temperature circuit.
Intake Manifold 1 Temperature Sensor Circuit - Possible white smoke. Fan will stay ON if
154 Voltage Below Normal, or Shorted to Low controlled by ECM. No engine protection for
105 Source. Low signal voltage detected at intake intake manifold air temperature.
4 manifold air temperature circuit.
Intake Manifold 1 Temperature - Data Valid but Progressive power derate increasing in
155 Above Normal Operational Range - Most severity from time of alert. If Engine Protection
105 Severe Level. Intake manifold air temperature Shutdown feature is enabled, engine will shut
0 signal indicates intake manifold air temperature down 30 seconds after Red Stop Lamp starts
above engine protection critical limit. flashing.
187 Sensor Supply 2 Circuit - Voltage Below Normal, Engine power derate.
520195 or Shorted to Low Source. Low voltage detected
4 at the sensor supply number 2 circuit.
195 Coolant Level Sensor 1 Circuit - Voltage Above None on performance.
111 Normal, or Shorted to High Source. High signal
3 voltage detected at engine coolant level circuit.
196 Coolant Level Sensor 1 Circuit - Voltage Below None on performance.
111 Normal, or Shorted to Low Source. Low signal
4 voltage detected at engine coolant level circuit.
197 Coolant Level - Data Valid but Below Normal None on performance.
111 Operational Range - Moderately Severe Level.
18 Low coolant level has been detected.
Barometric Pressure Sensor Circuit - Voltage Engine power derate.
221
Above Normal, or Shorted to High Source. High
108
signal voltage detected at barometric pressure
3
circuit.

3-23
Fault code
J1939 SPN Reason Effect (only when fault code is active)
J1939 FMI
Barometric Pressure Sensor Circuit - Voltage Engine power derate.
222
Below Normal, or Shorted to Low Source. Low
108
signal voltage detected at barometric pressure
4
circuit.
227 Sensor Supply 2 Circuit - Voltage Above Normal, Engine power derate.
520195 or Shorted to High Source. High voltage
3 detected at sensor supply number 2 circuit.
Engine Crankshaft Speed/Position - Data Valid Fuel injection disabled until engine speed falls
234
but Above Normal Operational Range - Most below the overspeed limit.
190
Severe Level. Engine speed signal indicates
0
engine speed above engine protection limit.
Coolant Level - Data Valid but Below Normal Progressive power derate increasing in
235 Operational Range - Most Severe Level. Low severity from time of alert. If Engine Protection
111 engine coolant level detected. Shutdown feature is enabled, engine will shut
1 down 30 seconds after Red Stop Lamp starts
flashing.
237 External Speed Command Input (Multiple Unit
644 Synchronization) - Data Erratic, Intermittent, or
2 Incorrect. Communication between multiple
engines may be intermittent.
238 Sensor Supply 3 Circuit - Voltage Below Normal, Possible hard starting and rough running.
520196 or Shorted to Low Source. Low voltage detected
4 on the +5 volt sensor supply circuit to the engine
speed sensor.
241 Wheel-based vehicle speed - Data erratic, Engine speed limited to ,maximum engine
84 intermittent, or incorrect. The ECM lost the speed without VSS parameter value. Cruise
2 vehicle speed signal. control, gear-down protection, and road speed
governor will not work.
242 Wheel-based vehicle speed sensor circuit Engine speed limited to maximum engine
84 tampering has been detected - Abnormal rate of speed without VSS parameter value. Cruise
10 change. Signal indicates an intermittent control, gear-down protection, and road speed
connection or VSS tampering. g+H53overnor will not work.
245 Fan control circuit - Voltage below normal, or The fan may stay on continuously or not run at
647 shorted to low source. Low signal voltage all.
4 detected at the fan control circuit when
commanded on.
271 Fuel pump pressurizing assembly 1 circuit - Engine will run poorly at idle. Engine will have
1347 Voltage below normal, or shorted to low source. low power. Fuel pressure will be higher than
4 Low signal voltage detected at the fuel pump commanded.
actuator circuit.
Fuel pump pressurizing assembly 1 circuit - Engine will not run or engine will run poorly.
272
Voltage above normal, or shorted to high source.
1347
High signal voltage or open circuit detected at
3
the fuel pump actuator circuit.
281 Fuel pump pressur izing assembly 1 - Engine will not run or possible low power.
1347 Mechanical system not responding properly or
7 out of adjustment.
SAE J1939 multiplexing PGN timeout error - At least one multiplexed device will not
285
Abnormal update rate. The ECM expected operate properly.
639
information from a multiplexed device but did not
9
receive it soon enough or did not receive it at all.
SAE J1939 multiplexing configuration error - At least one multiplexed device will not
286
Out of calibration. The ECM expected operate properly.
639
information from a multiplexed device but only
13
received a portion of the necessary information.

3-24
Fault code
J1939 SPN Reason Effect (only when fault code is active)
J1939 FMI
SAE J1939 multiplexed accelerator pedal or Engine may only idle or engine will not
287 lever sensor system - received network data In accelerate to full speed.
91 error. The OEM vehicle electronic control unit
19 (VECM) detected a fault with its accelerator
pedal.
SAE J1939 Multiplexing Remote Accelerator The engine will not respond to the remote
288 Pedal or Lever Position Sensor Circuit - throttle. Engine may only idle. The primary or
974 Received Network Data In Error. The OEM cab accelerator may be able to be used.
19 vehicle electronic control unit (VECM) detected
a fault with the remote accelerator.
292 Auxiliary temperature Sensor Input 1 - Special Possible engine power derate.
441 instructions.
14
Auxiliary temperature sensor input 1 circuit - None on performance.
293 Voltage above normal, or shorted to high
441 source. High signal voltage or open circuit
3 detected at the OEM auxiliary temperature
circuit.
Auxiliary temperature sensor input 1 circuit - None on performance.
294 Voltage below normal, or shorted to low source.
441 Low signal voltage detected at the OEM
4 auxiliary temperature circuit.
296 Auxiliary pressure sensor input 1 - Special Possible engine power derate.
1388 instructions.
14
Auxiliary pressure sensor input 1 circuit - None on performance.
297
Voltage above normal, or shorted to high
1388
source. High signal voltage detected at the OEM
3
pressure circuit.
Auxiliary pressure sensor input 1 circuit - None on performance.
298 Voltage below normal, or shorted to low source.
1388 Low signal voltage or open circuit detected at
4 the OEM pressure circuit.
319 Real time clock power interrupt - Data erratic, None on performance. Data in the ECM will
251 intermittent, or incorrect. Real time clock lost not have accurate time and date information.
2 power.
Injector solenoid driver cylinder 1 circuit - Engine can possibly misfire or run rough.
Current below normal, or open circuit. High
322 resistance detected on injector number 1 circuit
651 or no current detected at number 1 injector
5 driver or return pin when the voltage supply at
the harness is on.
Injector solenoid driver cylinder 5 circuit - Engine can possibly misfire or run rough.
Current below normal, or open circuit. High
323 resistance detected on injector number 5 circuit
655 or no current detected at number 5 injector
5 driver or return pin when the voltage supply at
the harness is on.
Injector solenoid driver cylinder 3 circuit - Engine can possibly misfire or run rough.
Current below normal, or open circuit. High
324 resistance detected on injector number 3 circuit
653 or no current detected at number 3 injector
5 driver or return pin when the voltage supply at
the harness is on.
Injector solenoid driver cylinder 6 circuit - Engine can possibly misfire or run rough.
Current below normal, or open circuit. High
325 resistance detected on injector number 6 circuit
656 or no current detected at number 6 injector
5 driver or return pin when the voltage supply at
the harness is on.

3-25
Fault code
J1939 SPN Reason Effect (only when fault code is active)
J1939 FMI
Injector solenoid driver cylinder 2 circuit - Engine can possibly misfire or run rough.
Current below normal, or open circuit. High
331
resistance detected on injector number 2 circuit
652
or no current detected at number 2 injector
5
driver or return pin when the voltage supply at
the harness is on.
Injector solenoid driver cylinder 4 circuit - Engine can possibly misfire or run rough.
Current below normal, or open circuit. High
332
resistance detected on injector number 4 circuit
654
or no current detected at number 4 injector
5
driver or return pin when the voltage supply at
the harness is on.
Engine coolant temperature - Data erratic, The ECM will estimate engine coolant
334
intermittent, or incorrect. The engine coolant temperature.
110
temperature reading is not changing with engine
2
operating conditions.
342 Electronic calibration code incompatibility - Out Possible no noticeable performance effects,
630 of calibration. An incompatible calibration has engine dying, or hard starting.
13 been detected in the ECM.
343 Engine control module warning internal No performance effects or possible severe
620 hardware failure - Bad intelligent device or power derate.
12 component. Internal ECM failure.
351 Injector power supply - Bad intelligent device or Possible smoke, low power, engine misfire,
627 component. The ECM measured injector boost and/or engine will not start.
12 voltage is low.
352 Sensor supply 1 circuit - Voltage below normal, Engine power derate.
1079 or shorted to low source. Low voltage detected
4 at sensor supply number 1 circuit.
386 Sensor supply 1 circuit - Voltage above normal, Engine power derate.
1079 or shorted to high source. High voltage detected
3 at sensor supply number 1 circuit.
Engine oil rifle pressure - Data valid but below Progressive power derate increasing in
415 normal operational range - Most severe level. Oil severity from time of alert. If engine protection
100 pressure signal indicates oil pressure below the shutdown feature is enabled, engine will shut
1 engine protection critical limit. down 30 seconds after red stop lamp starts
flashing.
418 Water in fuel indicator - Data valid but above Possible white smoke, loss of power, or hard
97 normal operational range - Least severe level. starting.
15 water has been detected in the fuel filter.
428 Water in fuel indicator sensor circuit - Voltage None on performance. No water in fuel
97 above normal, or shorted to high source. High warning available.
3 voltage detected at the water in fuel circuit.
429 Water in fuel indicator sensor circuit - Voltage None on performance. No water in fuel
97 below normal, or shorted to low source. Low warning available.
4 voltage detected at the water in fuel circuit.
Accelerator pedal or lever idle validation switch - Engine will only idle.
431 Data erratic, intermittent, or incorrect. Voltage
558 detected simultaneously on both idle validation
2 and off-idle validation switches.
Accelerator pedal or lever idle validation circuit - Engine will only idle.
432 Out of calibration. Voltage at idle validation
558 on-idle and off-idle circuit does not match
13 accelerator pedal position.

3-26
Fault code
J1939 SPN Reason Effect (only when fault code is active)
J1939 FMI
Engine oil rifle pressure - Data erratic, None on performance. No engine protection
435
intermittent, or incorrect. An error in the engine for oil pressure.
100
oil pressure switch signal was detected by the
2
ECM.
Battery 1 voltage - Data valid but below normal Engine may stop running or be difficult to start.
441
operational range - Moderately severe level.
168
ECM supply voltage is below the minimum
18
system voltage level.
Battery 1 Voltage - Data valid but above normal Possible electrical damage to all electrical
442
operational range - Moderately severe level. components.
168
ECM supply voltage is above the maximum
16
system voltage level.
449 Injector metering rail 1 pressure - Data valid but None or possible engine noise associated with
157 above normal operational range - Most severe higher injection pressures (especially at idle or
0 level. light load). Engine power is reduced.
Injector metering rail 1 pressure sensor circuit - Power and or speed derate.
451
Voltage above normal, or shorted to high source.
157
High signal voltage detected at the rail fuel
3
pressure sensor circuit.
Injector metering rail 1 pressure sensor circuit - Power and or speed derate.
452
Voltage below normal, or shorted to low source.
157
Low signal voltage detected at the rail fuel
4
pressure sensor circuit.
Intake manifold 1 temperature - Data valid but Progressive power derate increasing in
488 above normal operational range - Moderately severity from time of alert.
157 severe level. Intake manifold air temperature
16 signal indicates intake manifold air temperature
is above the engine protection warning limit.
497 Multiple unit synchronization switch - Data
1377 erratic, intermittent, or incorrect.
2
523 Auxiliary intermediate (PTO) speed switch None on performance.
611 validation - Data erratic, intermittent, or
2 incorrect.
Auxiliary input/output 2 circuit - Voltage above None on performance.
527 normal, or shorted to high source. High signal
702 voltage or open circuit has been detected at the
3 auxiliary input/output 2 circuit.
528 Auxiliary alternate torque validation switch - None on performance.
93 Data erratic, intermittent, or incorrect.
2
Auxiliary input/output 3 circuit - Voltage above
529
normal, or shorted to high source. Low signal
703
voltage has been detected at the auxiliary input/
3
output 2 circuit.
Injector metering rail 1 pressure - Data valid but The ECM will estimate fuel pressure and
553 above normal operational range - Moderately power is reduced.
157 severe level. The ECM has detected that fuel
16 pressure is higher than commanded pressure.
Injector metering rail 1 pressure - Data erratic, Possibly hard to start, low power, or engine
554 Intermittent, or incorrect. The ECM has smoke.
157 detected that the fuel pressure signal is not
2 changing.

3-27
Fault code
J1939 SPN Reason Effect (only when fault code is active)
J1939 FMI
Injector metering rail 1 pressure - Data Valid Either the engine will not start or the engine
559 but Below Normal Operational Range - will not have starter lockout protection.
157 Moderately Severe Level. The ECM has
18 detected that fuel pressure is lower than
commanded pressure.
Starter relay driver circuit - Voltage above The engine will not have starter lockout
584
normal, or shorted to high source. Open circuit protection.
677
or high voltage detected at starter lockout
3
circuit.
585 Starter relay driver circuit - Voltage below Engine power derate. The ECM uses an
677 normal, or shorted to low source. Low voltage estimated turbocharger speed.
4 detected at starter lockout circuit.
Turbocharger 1 speed - Data valid but above Amber lamp will light until high battery voltage
595
normal operational range - Moderately severe condition is corrected.
103
level. High turbocharger speed has been
16
detected.
599 Auxiliary commanded dual output shutdown - None or possible engine noise associated with
640 Special instructions. higher injection pressures (especially at idle or
14 light load). Engine power is reduced.
Turbocharger 1 speed - Data valid but below Engine can run rough. Possibly poor starting
687
normal operational range - Moderately severe capability. Engine runs using backup speed
103
level. Low turbocharger speed detected by the sensor. Engine power is reduced.
18
ECM.
689 Engine crankshaft speed/position - Data Engine power derate.
190 erratic, intermittent, or incorrect. Loss of signal
2 from crankshaft sensor.
Turbocharger 1 compressor inlet temperature Engine power derate.
691 circuit - Voltage above normal, or shorted to
1172 high source. High signal voltage detected at
3 turbocharger compressor inlet air temperature
circuit.
Turbocharger 1 compressor inlet temperature Engine will run derated. Excessive black
692
circuit - Voltage below normal, or shorted to low smoke, hard start, and rough idle possible.
1172
source. Low signal voltage detected at
4
turbocharger compressor inlet air tempera
Engine speed / position camshaft and Possible no noticeable performance effects,
crankshaft misalignment - Mechanical system engine dying, or hard starting.
731
not responding properly or out of adjustment.
723
mechanical misalignment between the
7
crankshaft and camshaft engine speed
sensors.
757 Electronic control module data lost - Condition Possible poor starting. Engine power derate.
611 exists. Severe loss of data from the ECM.
31
Engine camshaft speed / position sensor - Possible engine power derate.
778
Data erratic, intermittent, or incorrect. The ECM
723
has detected an error in the camshaft position
2
sensor signal.
Auxiliary equipment sensor input 3 - Root Possible no noticeable performance effects or
779 cause not known. e n g i n e d y i n g o r h a r d s t a r t i n g . Fa u l t
703 information, trip information, and maintenance
11 monitor data may be inaccurate.

3-28
Fault code
J1939 SPN Reason Effect (only when fault code is active)
J1939 FMI
Power supply lost with ignition on - Data erratic, Engine will shut down.
intermittent, or incorrect. Supply voltage to the
1117 ECM fell below 6.2 volts momentarily, or the
627 ECM was not allowed to power down correctly
2 (retain battery voltage for 30 seconds after key
OFF).
1633 OEM datalink cannot transmit - Data erratic, Engine will only idle.
625 intermittent, or incorrect. Communications
2 within the OEM datalink network is intermittent.
Sensor supply 4 circuit - Voltage above normal, Engine will only idle.
2185 or shor ted to high source. High voltage
520197 detected at +5 volt sensor supply circuit to the
3 accelerator pedal position sensor.
Sensor supply 4 circuit - Voltage below normal, Possibly hard to start, low power, or engine
2186 or shorted to low source. Low voltage detected smoke.
520197 at +5 volt sensor supply circuit to the
4 accelerator pedal position sensor.
Injector metering rail 1 pressure - Data valid but Engine may be difficult to start.
2249 below normal operational range - Most severe
157 level. The ECM has detected that fuel pressure
1 is lower than commanded pressure.
Electric lift pump for engine fuel supply circuit - Engine may be difficult to start.
2265 Voltage above normal, or shorted to high
1075 source. High voltage or open detected at the
3 fuel lift pump signal circuit.
Electric lift pump for engine fuel supply circuit - Possible low power.
2266 Voltage below normal, or shorted to low source.
1075 Low signal voltage detected at the fuel lift pump
4 circuit.
Electronic fuel injection control valve circuit -Engine may exhibit misfire as control switches
2311 Condition exists. Fuel pump actuator circuit from the primary to the backup speed sensor.
633 resistance too high or too low. Engine power is reduced while the engine
31 operates on the backup speed sensor.
2321 Engine crankshaft speed/position - Data erratic, Possible low power.
190 intermittent, or incorrect. crankshaft engine
2 speed sensor intermittent synchronization.
Engine camshaft speed / position sensor - Data Engine power derate.
2322
erratic, intermittent, or incorrect. Camshaft
723
engine speed sensor intermittent
2
synchronization.
2345 Turbocharger 1 Speed - Abnormal rate of Engine power derate.
103 change. The turbocharger speed sensor has
10 detected an erroneous speed value.
Turbocharger turbine inlet temperature Engine power derate.
2346 (Calculated) - Data valid but above normal
2789 operational range - Least severe level.
15 Turbocharger turbine inlet temperature has
exceeded the engine protection limit.
2347 Turbocharger compressor outlet temperature Engine brake on cylinders 1, 2, and 3 can not
2790 (Calculated) - Data valid but above normal be activated or exhaust brake will not operate.
15 operational range - Least severe level.
2377 Fan control circuit - Voltage above normal, or Variable geometry turbocharger will go to the
647 shorted to high source. Open circuit or high open position.
3 voltage detected at the fan control circuit.

3-29
Fault code
J1939 SPN Reason Effect (only when fault code is active)
J1939 FMI
2384 VGT actuator driver circuit - Voltage below Variable geometry turbocharger may be in
641 normal, or shorted to low source. Low voltage either the open or closed position.
4 detected at turbocharger control valve circuit.
VGT actuator driver circuit - Voltage above The intake air heaters may be ON or OFF all
2385
normal, or shorted to high source. Open circuit the time.
641
or high voltage detected at turbocharger
3
control valve circuit.
2555 Intake air heater 1 circuit - Voltage above The intake air heaters may be ON or OFF all
729 normal, or shorted to high source. High voltage the time.
3 detected at the intake air heater signal circuit.
2556 Intake air heater 1 circuit - Voltage below Can not control transmission.
729 normal, or shorted to low source. Low voltage
4 detected at the intake air heater signal circuit.
2557 Auxiliary PWM driver 1 circuit - Voltage above Can not control transmission.
697 normal, or shorted to high source. High signal
3 voltage detected at the analog torque circuit.
2558 Auxiliary PWM driver 1 circuit - Voltage below Power derate and possible engine shutdown if
697 normal, or shorted to low source. Low signal engine protection shutdown feature is enabled.
4 voltage detected at the analog torque circuit.
Intake manifold 1 pressure - Data erratic,
2973 intermittent, or incorrect. The ECM has
102 detected an intake manifold pressure signal
2 that is too high or low for current engine
operating conditions.

3-30
3) DEFINITION OF OPERATING MODES
(1) Normal
There's no failure detected in the transmission system or the failure has no or slight effects on
transmission control. TCU will work without or in special cases with little limitations. (See
following table)
(2) Substitute clutch control
TCU can't change the gears or the direction under the control of the normal clutch modulation.
TCU uses the substitute strategy for clutch control. All modulations are only time controlled.
(Comparable with EST 25)
(3) Limp-home
The detected failure in the system has strong limitations to transmission control. TCU can
engage only one gear in each direction. In some cases only one direction will be possible.
TCU will shift the transmission into neutral at the first occurrence of the failure. First, the operator
must shift the gear selector into neutral position.
If output speed is less than a threshold for neutral to gear and the operator shifts the gear selector
into forward or reverse, the TCU will select the limp-home gear.
If output speed is less than a threshold for reversal speed and TCU has changed into the limp-
home gear and the operator selects a shuttle shift, TCU will shift immediately into the limp-home
gear of the selected direction.
If output speed is greater than the threshold, TCU will shift the transmission into neutral. The
operator has to slow down the vehicle and must shift the gear selector into neutral position.
(4) Transmission-shutdown
TCU has detected a severe failure that disables control of the transmission.
TCU will shut off the solenoid valves for the clutches and also the common power supply (VPS1).
Transmission shifts to neutral. The park brake will operate normally, also the other functions
which use ADM1 to ADM8.
The operator has to slow down the vehicle. The transmission will stay in neutral.
(5) TCU-shutdown
TCU has detected a severe failure that disables control of system.
TCU will shut off all solenoid valves and also both common power supplies (VPS1, VPS2). The
park brake will engage, also functions are disabled which use ADM 1 to ADM 8.
The transmission will stay in neutral.
※ Abbreviations
OC : Open circuit
SC : Short circuit
OP mode : Operating mode
TCU : Transmission control unit
EEC : Electronic engine controller
PTO : Power take off

3-31
 4) TRANSMISSION FAULT CODES
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
11 Logical error at gear range signal TCU shifts transmission to · Check the cables from TCU to shift
TCU detected a wrong signal combination neutral lever
for the gear range OP-mode : Transmission · Check signal combinations of shift
·Cable from shift lever to TCU is broken shutdown lever positions for gear range
·Cable is defective and is contacted to ※ Failure cannot be detected in
battery voltage or vehicle ground systems with DW2/DW3 shift lever.
·Shift lever is defective Fault is taken back if TCU detects a
valid signal for the position
12 Logical error at direction select signal TCU shifts transmission to · Check the cables from TCU to shift
TCU detected a wrong signal combination neutral lever
for the direction OP-Mode : Transmission · Check signal combinations of shift
·Cable from shift lever to TCU is broken shutdown lever positions F-N-R
·Cable is defective and is contacted to ※ Fault is taken back if TCU detects a
battery voltage or vehicle ground valid signal for the direction at the
·Shift lever is defective shift lever
13 Logical error at engine derating device After selecting neutral, · Check engine derating device
TCU detected no reaction of engine while TCU change to OP mode ※ This fault is reset after power up of
derating device active limp home TCU
15 Logical error at direction select signal 2 TCU shifts transmission to · Check the cables from TCU to shift
shift lever neutral if selector active lever 2
TCU detected a wrong signal combination OP mode : Transmission · Check signal combinations of shift
for the direction shutdown if lever positions F-N-R
·Cable from shift lever 2 to TCU is broken elector active ※ Fault is taken back if TCU detects a
·Cable is defective and is contacted to valid neutral signal for the direction
battery voltage or vehicle ground at the shift lever
·Shift lever is defective
16 Logical error at axle connection OP mode : Normal · Check the cables from TCU to
Feedback axle connection measured by feedback axle connection switch
TCU and output signal axle connection · Check signals of the feedback axle
don't fit connection switch
·Axle can't be connected or disconnect-
ed due to mechanical problem
·One of the cables from feedback axle
connection switch to TCU is broken
21 S.C. to battery voltage at clutch cut off Clutch cut off function is · Check the cable from TCU to the
input disabled sensor
The measured voltage is too high: OP mode : Normal · Check the connectors
·Cable is defective and is contacted to · Check the clutch cut off sensor
battery voltage
·Clutch cut off sensor has an internal
defect
·Connector pin is contacted to battery
voltage
22 S.C. to ground or O.C. at clutch cut off Clutch cut off function is · Check the cable from TCU to the
input disabled sensor
The measured voltage is too low: OP mode : Normal · Check the connectors
·Cable is defective and is contacted to · Check the clutch cut off sensor
vehicle ground
·Cable has no connection to TCU
·Clutch cut off sensor has an internal
defect
·Connector pin is contacted to vehicle
ground or is broken

3-32
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
23 S.C. to battery voltage at load sensor R e t a r d e r f u n c t i o n i s · Check the cable from TCU to the
input affected TCU uses default sensor
The measured voltage is too high: load · Check the connectors
·Cable is defective and is contacted to OP mode : Normal · Check the load sensor
battery voltage · Check the assembly tolerances of
·Load sensor has an internal defect load sensor
·Connector pin is contacted to battery ※ Availability of retarder depends on
voltage default load
24 S.C. to ground or O.C. at load sensor R e t a r d e r f u n c t i o n i s · Check the cable from TCU to the
input affected TCU use default sensor
The measured voltage is too low: load · Check the connectors
·Cable is defective and is contacted to OP mode : Normal · Check the load sensor
vehicle ground · Check the assembly tolerances of
·Cable has no connection to TCU load sensor
·Load sensor has as internal defect ※ Availability of retarder depends on
·Connector pin is contacted to vehicle default load
ground or is broken
25 S.C. to batter y voltage or O.C. at No reaction, TCU use · Check the cable from TCU to the
transmi-ssion sump temperature sensor default temperature sensor
input OP mode : Normal · Check the connectors
The measured voltage is too high: · Check the temperature sensor
·Cable is defective and is contacted to
battery voltage
·Cable has no connection to TCU
·Temperature sensor has an internal
defect
·Connector pin is contacted to battery
voltage or is broken
26 S.C. to batter y voltage or O.C. at No reaction, TCU uses · Check the cable from TCU to the
transmi-ssion sump temperature sensor default temperature sensor
input OP mode : Normal · Check the connectors
The measured voltage is too low: · Check the temperature sensor
·Cable is defective and is contacted to
vehicle ground
·Temperature sensor has an internal
defect
·Connector pin is contacted to vehicle
ground
27 S.C. to batter y voltage or O.C. at No reaction, TCU uses · Check the cable from TCU to the
retarder temperature sensor input default temperature sensor
The measured voltage is too high: OP mode : Normal · Check the connectors
·Cable is defective and is contacted to · Check the temperature sensor
battery voltage
·Cable has no connection to TCU
·Temperature sensor has an internal
defect
·Connector pin is contacted to battery
voltage or is broken

3-33
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
28 S.C. to ground at retarder temperature No reaction, TCU uses · Check the cable from TCU to the
sensor input default temperature sensor
The measured voltage is too low: OP mode : Normal · Check the connectors
·Cable is defective and is contacted to · Check the temperature sensor
vehicle ground
·Temperature sensor has an internal
defect
·Connector pin is contacted to vehicle
ground
29 S.C. to batter y voltage or O.C. at No reaction, TCU uses · Check the cable from TCU to the
converter output temperature sensor default temperature sensor
input OP mode : Normal · Check the connectors
The measured voltage is too high: · Check the temperature sensor
·Cable is defective and is contacted to
battery voltage
·Cable has no connection to TCU
·Temperature sensor has an internal
defect
·Connector pin is contacted to battery
voltage or is broken
30 S.C. to ground at conver ter output No reaction, TCU uses · Check the cable from TCU to the
temperature sensor input default temperature sensor
The measured voltage is too low: OP mode : Normal · Check the connectors
·Cable is defective and is contacted to · Check the temperature sensor
vehicle ground
·Temperature sensor has an internal
defect
·Connector pin is contacted to vehicle
ground
31 S.C. to battery voltage or O.C. at engine OP mode : Substitute clutch · Check the cable from TCU to the
speed input control sensor
TCU measures a voltage higher than · Check the connectors
7.00V at speed input pin · Check the speed sensor
·Cable is defective and is contacted to
battery voltage
·Cable has no connection to TCU
·Speed sensor has an internal defect
·Connector pin is contacted to battery
voltage or has no contact
32 S.C. to ground at engine speed input OP mode : Substitute clutch · Check the cable from TCU to the
TCU measures a voltage less than 0.45V control sensor
at speed input pin · Check the connectors
·Cable/connector is defective and is · Check the speed sensor
contacted to vehicle ground
·Speed sensor has an internal defect

3-34
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
33 Logical error at engine speed input OP mode : Substitute clutch · Check the cable from TCU to the
TCU measures a engine speed over a control sensor
threshold and the next moment the · Check the connectors
measured speed is zero · Check the speed sensor
·Cable/connector is defective and has · Check the sensor gap
bad contact ※ This fault is reset after power up of
·Speed sensor has an internal defect TCU
·Sensor gap has the wrong size
34 S.C. to battery voltage or O.C. at turbine OP mode : Substitute clutch · Check the cable from TCU to the
speed input control sensor
TCU measures a voltage higher than If a failure is existing at · Check the connectors
7.00V at speed input pin output speed, · Check the speed sensor
·Cable is defective and is contacted to TCU shifts to neutral
vehicle battery voltage OP mode : Limp home
·Cable has no connection to TCU
·Speed sensor has an internal defect
·Connector pin is contacted to battery
voltage or has no contact
35 S.C. to ground at turbine speed input OP mode : Substitute clutch · Check the cable from TCU to the
TCU measures a voltage less than 0.45V control sensor
at speed input pin If a failure is existing at · Check the connectors
·Cable/connector is defective and is output speed, · Check the speed sensor
contacted to vehicle ground TCU shifts to neutral ※ This fault is reset after power up of
·Speed sensor has an internal defect OP mode : Limp home TCU
36 Logical error at turbine speed input OP mode : Substitute clutch · Check the cable from TCU to the
TCU measures a turbine speed over a control sensor
threshold and at the next moment the If a failure is existing at · Check the connectors
measured speed is zero output speed, · Check the speed sensor
·Cable/connector is defective and has TCU shifts to neutral · Check the sensor gap
bad contact OP mode : Limp home
·Speed sensor has an internal defect
·Sensor gap has the wrong size
37 S.C. to battery voltage or O.C. at internal OP mode : Substitute clutch · Check the cable from TCU to the
speed input control sensor
TCU measures a voltage higher than · Check the connectors
7.00V at speed input pin · Check the speed sensor
·Cable is defective and is contacted to
vehicle battery voltage
·Cable has no connection to TCU
·Speed sensor has an internal defect
·Connector pin is contacted to battery
voltage or has no contact
38 S.C. to ground at turbine speed input OP mode : Substitute clutch · Check the cable from TCU to the
TCU measures a voltage less than 0.45V control sensor
at speed input pin · Check the connectors
·Cable/connector is defective and is · Check the speed sensor
contacted to vehicle ground
·Speed sensor has an internal defect

3-35
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
39 Logical error at internal speed input OP mode : Substitute clutch · Check the cable from TCU to the
TCU measures a internal speed over a control sensor
threshold and at the next moment the · Check the connectors
measured speed is zero · Check the speed sensor
·Cable/connector is defective and has · Check the sensor gap
bad contact ※ This fault is reset after power up of
·Speed sensor has an internal defect TCU
·Sensor gap has the wrong size
3A S.C. to battery voltage or O.C. at output Special mode for gear · Check the cable from TCU to the
speed input selection sensor
TCU measures a voltage higher than OP mode : S u b s t i t u t e · Check the connectors
12.5V at speed input pin clutch control · Check the speed sensor
·Cable is defective and is contacted to If a failure is existing at
battery voltage turbine speed,
·Cable has no connection to TCU TCU shifts to neutral
·Speed sensor has an internal defect OP mode : lamp home
·Connector pin is contacted to battery
voltage or has no contact
3B S.C. to ground at output speed input Special mode for gear · Check the cable from TCU to the
TCU measures a voltage less than 1.00V selection sensor
at speed input pin OP mode : Substitute clutch · Check the connectors
·Cable/connector is defective and is control · Check the speed sensor
contacted to vehicle ground If a failure is existing at
·Speed sensor has an internal defect turbine speed,
TCU shifts to neutral
OP mode : lamp home
3C Logical error at output speed input Special mode for gear · Check the cable from TCU to the
TCU measures a turbine speed over a selection sensor
threshold and at the next moment the OP mode : Substitute clutch · Check the connectors
measured speed is zero control · Check the speed sensor
·Cable/connector is defective and has If a failure is existing at · Check the sensor gap
bad contact turbine speed, ※ This fault is reset after power up of
·Speed sensor has an internal defect TCU shifts to neutral TCU
·Sensor gap has the wrong size OP mode : lamp home
3D Turbine speed zero doesn't fit to other - · Not used
speed signals
3E Output speed zero doesn't fit to other Special mode for gear · Check the sensor signal of output
speed signals selection speed sensor
If transmission is not neutral and the OP mode : Substitute clutch · Check the sensor gap of output
shifting has finished, control speed sensor
TCU measures output speed zero and If a failure is existing at · Check the cable from TCU to the
turbine speed or internal speed not equal turbine speed, sensor
to zero. TCU shifts to neutral ※ This fault is reset after power up of
·Speed sensor has an internal defect OP mode : lamp home TCU
·Sensor gap has the wrong size

3-36
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
71 S.C. to battery voltage at clutch K1 TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the valve OP mode : Limp home gearbox
is out of limit, the voltage at K1 valve is too If failure at another clutch · Check the connectors from TCU to
high is pending the gearbox
·Cable/connector is defective and has TCU shifts to neutral · Check the regulator resistance*
contact to battery voltage OP mode : TCU shutdown · Check internal wire harness of the
·Cable/connector is defective and has gearbox
contact to another regulator output of * See page 3-52
the TCU
·Regulator has an internal defect
72 S.C. to ground at clutch K1 TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the valve OP mode : Limp home gearbox
is out of limit, the voltage at K1 valve is too If failure at another clutch · Check the connectors from gearbox
low is pending to TCU
·Cable/connector is defective and has TCU shifts to neutral · Check the regulator resistance*
contact to vehicle ground OP mode : TCU shutdown · Check internal wire harness of the
·Regulator has an internal defect gearbox
* See page 3-52
73 O.C. at clutch K1 TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the OP mode : Limp home gearbox
valve is out of limit If failure at another clutch · Check the connectors from gearbox
·Cable/connector is defective and has no is pending to TCU
contact to TCU TCU shifts to neutral · Check the regulator resistance*
·Regulator has an internal defect OP mode : TCU shutdown · Check internal wire harness of the
gearbox
* See page 3-52
74 S.C. to battery voltage at clutch K2 TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the OP mode : Limp home gearbox
valve is out of limit, the voltage at K2 valve If failure at another clutch · Check the connectors from gearbox
is too high is pending to TCU
·Cable/connector is defective and has TCU shifts to neutral · Check the regulator resistance*
contact to battery voltage OP mode : TCU shutdown · Check internal wire harness of the
·Cable/connector is defective and has gearbox
contact to another regulator output of * See page 3-52
the TCU
·Regulator has an internal defect
75 S.C. to ground at clutch K2 · Check the cable from TCU to the
TCU shifts to neutral
The measured resistance value of the valve OP mode : Limp home gearbox
is out of limit, the voltage at K2 valve is too · Check the connectors from gearbox
If failure at another clutch
low is pending to TCU
·Cable/connector is defective and has · Check the regulator resistance*
TCU shifts to neutral
contact to vehicle ground · Check internal wire harness of the
OP mode : TCU shutdown
·Regulator has an internal defect gearbox
* See page 3-52
76 O.C. at clutch K2 TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the OP mode : Limp home gearbox
valve is out of limit If failure at another clutch · Check the connectors from gearbox
·Cable/connector is defective and has no is pending to TCU
contact to TCU TCU shifts to neutral · Check the regulator resistance*
·Regulator has an internal defect OP mode : TCU shutdown · Check internal wire harness of the
gearbox
* See page 3-52

3-37
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
77 S.C. to battery voltage at clutch K3 TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the OP mode : Limp home gearbox
valve is out of limit, the voltage at K3 valve If failure at another clutch · Check the connectors from gearbox
is too high is pending to TCU
·Cable/connector is defective and has TCU shifts to neutral · Check the regulator resistance*
contact to battery voltage OP mode : TCU shutdown · Check internal wire harness of the
·Cable/connector is defective and has gearbox
contact to another regulator output of * See page 3-52
the TCU
·Regulator has an internal defect
78 S.C. to ground at clutch K3 · Check the cable from TCU to the
TCU shifts to neutral
The measured resistance value of the valve OP mode : Limp home gearbox
is out of limit, the voltage at K3 valve is too · Check the connectors from gearbox
If failure at another clutch
low is pending to TCU
·Cable/connector is defective and has · Check the regulator resistance*
TCU shifts to neutral
contact to vehicle ground · Check internal wire harness of the
OP mode : TCU shutdown
·Regulator has an internal defect gearbox
* See page 3-52
79 O.C. at clutch K2 TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the OP mode : Limp home gearbox
valve is out of limit If failure at another clutch · Check the connectors from gearbox
·Cable/connector is defective and has no is pending to TCU
contact to TCU TCU shifts to neutral · Check the regulator resistance*
·Regulator has an internal defect OP mode : TCU shutdown · Check internal wire harness of the
gearbox
* See page 3-52
7A S.C. to battery voltage at converter
- -
clutch
7B S.C. to ground at converter clutch - -
7C O.C. at converter clutch - ※ Not used
7D S.C. ground at engine derating device Engine derating will be on · Check the cable from TCU to the
·Cable is defective and is contacted to until engine derating device
vehicle ground TCU power down even if · Check the connectors from engine
·Engine derating device has an internal fault vanishes (Loose derating device to TCU
defect connection) · Check the resistance* of engine
·Connector pin is contacted to vehicle OP mode : Normal derating device
ground ※ Not used
* See page 3-52
7E S.C. battery voltage at engine derating No reaction · Check the cable from TCU to the
device OP mode : Normal engine derating device
·Cable/connector is defective and is · Check the connectors from backup
contacted to battery voltage alarm device to TCU
·Engine derating device has an internal · Check the resistance* of backup
defect alarm device
* See page 3-52

3-38
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
7F O.C. at engine derating device No reaction · Check the cable from TCU to the
TCU detected a wrong voltage at the OP mode : Normal engine derating device
output pin, that looks like a O.C. for this · Check the connectors from engine
output pin derating device to TCU
·C a b l e i s d e fe c t i ve a n d h a s n o · Check the resistance* of engine
connection to TCU derating device
·Engine derating device has an internal * See page 3-52
defect
·Connector has no connection to TCU
81 S.C. to battery voltage at clutch K4 TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the OP mode : Limp home gearbox
valve is out of limit, the voltage at K4 valve If failure at another clutch · Check the connectors from gearbox
is too high is pending to TCU
·Cable/connector is defective and has TCU shifts to neutral · Check the regulator resistance*
contact to battery voltage OP mode : TCU shutdown · Check internal wire harness of the
·Cable/connector is defective and has gearbox
contact to another regulator output of * See page 3-52
the TCU
·Regulator has an internal defect
82 S.C. to ground at clutch K4 TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the valve OP mode : Limp home engine derating device
is out of limit, the voltage at K4 valve is too If failure at another clutch · Check the connectors from gearbox
low is pending to TCU
·Cable/connector is defective and has TCU shifts to neutral · Check the regulator resistance*
contact to vehicle ground OP mode : TCU shutdown · Check internal wire harness of the
·Regulator has an internal defect gearbox
* See page 3-52
83 O.C. at clutch K4 · Check the cable from TCU to the
The measured resistance value of the TCU shifts to neutral gearbox
valve is out of limit OP mode : Limp home · Check the connectors from gearbox
·Cable/connector is defective and has If failure at another clutch to TCU
contact to TCU is pending · Check the regulator resistance*
·Regulator has an internal defect TCU shifts to neutral · Check internal wire harness of the
OP mode : TCU shutdown gearbox
* See page 3-52
84 S.C. to battery voltage at clutch K4 TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the OP mode : Limp home gearbox
valve is out of limit, the voltage at K4 valve If failure at another clutch · Check the connectors from gearbox
is too high is pending to TCU
·Cable/connector is defective and has TCU shifts to neutral · Check the regulator resistance*
contact to battery voltage OP mode : TCU shutdown · Check internal wire harness of the
·Cable/connector is defective and has gearbox
contact to another regulator output of * See page 3-52
the TCU
·Regulator has an internal defect
85 S.C. to ground at clutch KV TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the valve OP mode : Limp home gearbox
is out of limit, the voltage at K4 valve is too If failure at another clutch · Check the connectors from gearbox
low is pending to TCU
·Cable/connector is defective and has TCU shifts to neutral · Check the regulator resistance*
contact to vehicle ground OP mode : TCU shutdown · Check internal wire harness of the
·Regulator has an internal defect gearbox
* See page 3-52

3-39
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
86 O.C. at clutch KV TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the OP mode : Limp home gearbox
valve is out of limit If failure at another clutch · Check the connectors from gearbox
·Cable/connector is defective and has is pending to TCU
contact to TCU TCU shifts to neutral · Check the regulator resistance*
·Regulator has an internal defect OP mode : TCU shutdown · Check internal wire harness of the
gearbox
* See page 3-52
87 S.C. to battery voltage at clutch KR TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the OP mode : Limp home gearbox
valve is out of limit, the voltage at KR valve is If failure at another clutch · Check the connectors from gearbox
too high is pending to TCU
·Cable/connector is defective and has TCU shifts to neutral · Check the regulator resistance*
contact to battery voltage OP mode : TCU shutdown · Check internal wire harness of the
·Cable/connector is defective and has gearbox
contact to another regulator output of the * See page 3-52
TCU
·Regulator has an internal defect
88 S.C. to ground at clutch KR TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the valve OP mode : Limp home gearbox
is out of limit, the voltage at KR valve is too If failure at another clutch · Check the connectors from gearbox
low is pending to TCU
·Cable/connector is defective and has TCU shifts to neutral · Check the regulator resistance*
contact to vehicle ground OP mode : TCU shutdown · Check internal wire harness of the
·Regulator has an internal defect gearbox
* See page 3-52
89 O.C. at clutch KR TCU shifts to neutral · Check the cable from TCU to the
The measured resistance value of the OP mode : Limp home gearbox
valve is out of limit If failure at another clutch · Check the connectors from gearbox
·Cable/connector is defective and has no is pending to TCU
contact to TCU TCU shifts to neutral · Check the regulator resistance*
·Regulator has an internal defect OP mode : TCU shutdown · Check internal wire harness of the
gearbox
* See page 3-52
91 S.C. to ground at relay reverse warning Backup alarm will be on · Check the cable from TCU to the
alarm until backup alarm device
TCU detected a wrong voltage at the TCU power down even if · Check the connectors from backup
output pin, that looks like a S.C. to vehicle fault alarm device to TCU
ground vanishes(Loose connect- · Check the resistance* of backup
·Cable is defective and is contact to ion) alarm device
vehicle ground OP mode : Normal * See page 3-52
·Backup alarm device has an internal
defect
·Connector pin is contacted to vehicle
ground

3-40
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
92 S.C. to battery voltage at relay reverse No reaction · Check the cable from TCU to the
warning alarm OP mode : Normal backup alarm device
TCU detected a wrong voltage at the · Check the connectors from backup
output pin, that looks like a S.C. to battery alarm device to TCU
voltage · Check the resistance* of backup
·Cable is defective and is contacted to alarm device
battery voltage * See page 3-52
·Backup alarm device has an internal
defect
·Connector pin is contacted to battery
voltage
93 O.C. at relay reverse warning alarm No reaction · Check the cable from TCU to the
TCU detected a wrong voltage at the OP mode : Normal backup alarm device
output pin, that looks like a O.C. for this · Check the connectors from backup
output pin alarm device to TCU
·C a b l e i s d e fe c t i ve a n d h a s n o · Check the resistance* of backup
connection to TCU alarm device
·Backup alarm device has an internal * See page 3-52
defect
·Connector has no connection to TCU
94 S.C. to ground at relay starter interlock No reaction · Check the cable from TCU to the
TCU detected a wrong voltage at the OP mode : Normal stater interlock relay
output pin, that looks like a S.C. to vehicle · Check the connectors from starter
ground interlock relay to TCU
·Cable is defective and is connection to · Check the resistance* of starter
vehicle ground interlock relay
·Starter interlock relay has an internal * See page 3-52
defect
·Connector pin is contacted to vehicle
ground
95 S.C. to battery voltage at relay starter No reaction · Check the cable from TCU to the
interlock OP mode : Normal starter interlock relay
TCU detected a wrong voltage at the · Check the connectors from starter
output pin, that looks like a S.C. to battery interlock relay to TCU
voltage · Check the resistance* of starter
·C a b l e i s d e fe c t i ve a n d h a s n o interlock relay
connection to battery voltage * See page 3-52
·Starter interlock relay has an internal
defect
·Connector pin is contacted to battery
voltage

96 O.C. at relay starter interlock No reaction · Check the cable from TCU to the
TCU detected a wrong voltage at the OP mode : Normal starter interlock relay
output pin, that looks like a O.C. for this · Check the connectors from starter
output pin interlock relay to TCU
·C a b l e i s d e fe c t i ve a n d h a s n o · Check the resistance* of starter
connection to TCU interlock relay
·Starter interlock relay has an internal * See page 3-52
defect
·Connector has no connection to TCU

3-41
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
97 S.C. to ground at park brake solenoid No reaction · Check the cable from TCU to the
TCU detected a wrong voltage at the OP mode : Normal park brake solenoid
output pin, that looks like a S.C. to vehicle · Check the connectors from park
ground brake solenoid to TCU
·Cable is defective and is connection to · Check the resistance* of park brake
vehicle ground solenoid
·Park brake solenoid has an internal * See page 3-52
defect
·Connector pin is contacted to vehicle
ground
98 S.C. to battery voltage at park brake No reaction · Check the cable from TCU to the
solenoid Optional : (Some custom- park brake solenoid
TCU detected a wrong voltage at the ers) · Check the connectors from park
output pin, that looks like a S.C. to battery TCU shifts to neutral brake solenoid to TCU
voltage caused by park brake feed · Check the resistance* of park brake
·Cable is defective and is connection to back solenoid
battery voltage OP mode : Normal * See page 3-52
·Park brake solenoid has an internal
defect
·Connector pin is contacted to battery
voltage
99 O.C. at park brake solenoid No reaction · Check the cable from TCU to the
TCU detected a wrong voltage at the Optional : Some park brake solenoid
output pin, that looks like a O.C. for this customers · Check the connectors from park
output pin TCU shifts to neutral brake solenoid to TCU
·C a b l e i s d e fe c t i ve a n d h a s n o caused by park brake feed · Check the resistance* of park brake
connection to TCU back solenoid
·Park brake solenoid has an internal OP mode : Normal * See page 3-52
defect
·Connector has no connection to TCU
9A S.C. to ground at conver ter lock up No reaction · Check the cable from TCU to the
clutch solenoid OP mode : Normal converter clutch solenoid
TCU detected a wrong voltage at the · C h e ck t h e c o n n e c t o r s f r o m
output pin, that looks like a S.C. to vehicle converter clutch solenoid to TCU
ground · Check the resistance* of park brake
·Cable is defective and is contacted to solenoid
vehicle ground * See page 3-52
·Conver ter clutch solenoid has an
internal defect
·Connector pin is contacted to vehicle
ground
9B O.C. at converter lock up clutch solenoid Converter clutch always · Check the cable from TCU to the
TCU detected a wrong voltage at the open, converter clutch solenoid
output pin, that looks like a O.C. for this retarder not available · C h e ck t h e c o n n e c t o r s f r o m
output pin OP mode : Normal converter clutch solenoid to TCU
·C a b l e i s d e fe c t i ve a n d h a s n o · Check the resistance* of park brake
connection to TCU solenoid
·Conver ter clutch solenoid has an * See page 3-52
internal defect
·Connector has no connection to TCU

3-42
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
9C S.C. to battery voltage at converter lock No reaction · Check the cable from TCU to the
up clutch solenoid OP mode : Normal converter clutch solenoid
TCU detected a wrong voltage at the · C h e ck t h e c o n n e c t o r s f r o m
output pin, that looks like a S.C. to battery converter clutch solenoid to TCU
voltage · Check the resistance* of converter
·Cable is defective and has no contacted clutch solenoid
to battery voltage * See page 3-52
·Conver ter clutch solenoid has an
internal defect
·Connector pin is contacted to battery
voltage
9D S.C. to ground at retarder solenoid No reaction · Check the cable from TCU to the
TCU detected a wrong voltage at the OP mode : Normal retarder solenoid
output pin, that looks like a S.C. to vehicle · Check the connectors from retarder
ground solenoid to TCU
·Cable is defective and is contacted to · Check the resistance* of retarder
vehicle ground solenoid
·Retarder solenoid has an internal defect * See page 3-52
·Connector pin is contacted to vehicle
ground
9E O.C. at retarder solenoid No reaction · Check the cable from TCU to the
TCU detected a wrong voltage at the OP mode : Normal retarder solenoid
output pin, that looks like a O.C. for this · Check the connectors from retarder
output pin solenoid to TCU
·C a b l e i s d e fe c t i ve a n d h a s n o · Check the resistance* of retarder
connection to TCU solenoid
·Retarder solenoid has an internal defect * See page 3-52
·Connector has no connection to TCU
9F S.C. to batter y voltage at retarder No reaction · Check the cable from TCU to the
solenoid OP mode : Normal retarder solenoid
TCU detected a wrong voltage at the · Check the connectors from retarder
output pin, that looks like a S.C. to battery solenoid to TCU
voltage · Check the resistance* of retarder
·C a b l e i s d e fe c t i ve a n d h a s n o solenoid
connection to battery voltage * See page 3-52
·Retarder solenoid has an internal defect
·Connector pin is contacted to battery
voltage

3-43
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
A1 S.C. to ground at difflock or axle No reaction · Check the cable from TCU to the
connection solenoid OP mode : Normal difflock solenoid
TCU detected a wrong voltage at the · Check the connectors from difflock
output pin, that looks like a S.C. to vehicle solenoid to TCU
ground · Check the resistance* of difflock
·Cable is defective and is contacted to solenoid
vehicle ground * See page 3-52
·Difflock solenoid has an internal defect
·Connector pin is contacted to vehicle
ground
A2 S.C. to battery voltage at difflock or axle No reaction · Check the cable from TCU to the
connection solenoid OP mode : Normal difflock solenoid
TCU detected a wrong voltage at the · Check the connectors from difflock
output pin, that looks like a S.C. to battery solenoid to TCU
voltage · Check the resistance* of difflock
·C a b l e i s d e fe c t i ve a n d h a s n o solenoid
connection to battery voltage * See page 3-52
·Difflock solenoid has an internal defect
·Connector pin is contacted to battery
voltage
A3 O.C. at difflock or axle connection No reaction · Check the cable from TCU to the
solenoid OP mode : Normal difflock solenoid
TCU detected a wrong voltage at the · Check the connectors from difflock
output pin, that looks like a O.C. for this solenoid to TCU
output pin · Check the resistance* of difflock
·C a b l e i s d e fe c t i ve a n d h a s n o solenoid
connection to TCU * See page 3-52
·Difflock solenoid has an internal defect
·Connector has no connection to TCU
A4 S.C. to ground at warning signal output No reaction · Check the cable from TCU to the
TCU detected a wrong voltage at the OP mode : Normal warning device
output pin, that looks like a S.C. to vehicle · Check the connectors from warning
ground device to TCU
·Cable is defective and is contacted to · Check the resistance* of warning
vehicle ground device
·Warning device has an internal defect * See page 3-52
·Connector pin is contacted to vehicle
ground
A5 O.C. voltage at warning signal output No reaction · Check the cable from TCU to the
TCU detected a wrong voltage at the OP mode : Normal warning device
output pin, that looks like a O.C. for this · Check the connectors from warning
output pin device to TCU
·C a b l e i s d e fe c t i ve a n d h a s n o · Check the resistance* of warning
connection to TCU device
·Warning device has an internal defect * See page 3-52
·Connector has no connection to TCU
A6 S.C. to battery voltage at warning signal No reaction · Check the cable from TCU to the
output OP mode : Normal warning device
TCU detected a wrong voltage at the · Check the connectors from warning
output pin, that looks like a S.C. to battery device to TCU
voltage · Check the resistance* of warning
·Cable is defective and has is contacted device
to battery voltage * See page 3-52
·Warning device has an internal defect
·Connector pin is contacted to battery
voltage

3-44
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
B1 Slippage at clutch K1 TCU shifts to neutral · Check pressure at clutch K1
TCU calculates a differential speed at OP mode : Limp home · Check main pressure in the system
closed clutch K1. If this calculated value If failure at another clutch · Check sensor gap at internal speed
is out of range, TCU interprets this as is pending sensor
slipping clutch TCU shifts to neutral · Check sensor gap at output speed
·Low pressure at clutch K1 OP mode : TCU shutdown sensor
·Low main pressure · Check signal at internal speed
·Wrong signal at internal speed sensor sensor
·Wrong signal at output speed sensor · Check signal at output speed
·Wrong size of the sensor gap sensor
·Clutch is defective · Replace clutch
B2 Slippage at clutch K2 TCU shifts to neutral · Check pressure at clutch K2
TCU calculates a differential speed at OP mode : Limp home Check main pressure in the system
closed clutch K2. If this calculated value If failure at another clutch · Check sensor gap at internal speed
is out of range, TCU interprets this as is pending sensor
slipping clutch TCU shifts to neutral · Check sensor gap at output speed
·Low pressure at clutch K2 OP mode : TCU shutdown sensor
·Low main pressure · Check signal at internal speed
·Wrong signal at internal speed sensor sensor
·Wrong signal at output speed sensor · Check signal at output speed
·Wrong size of the sensor gap sensor
·Clutch is defective · Replace clutch
B3 Slippage at clutch K3 TCU shifts to neutral · Check pressure at clutch K3
TCU calculates a differential speed at OP mode : Limp home · Check main pressure in the system
closed clutch K3. If this calculated value If failure at another clutch · Check sensor gap at internal speed
is out of range, TCU interprets this as is pending sensor
slipping clutch TCU shifts to neutral · Check sensor gap at output speed
·Low pressure at clutch K3 OP mode : TCU shutdown sensor
·Low main pressure · Check signal at internal speed
·Wrong signal at internal speed sensor sensor
·Wrong signal at output speed sensor · Check signal at output speed
·Wrong size of the sensor gap sensor
·Clutch is defective Replace clutch
B4 Slippage at clutch K4 TCU shifts to neutral · Check pressure at clutch K4
TCU calculates a differential speed at OP mode : Limp home Check main pressure in the system
closed clutch K4. If this calculated value If failure at another clutch · Check sensor gap at internal speed
is out of range, TCU interprets this as is pending sensor
slipping clutch TCU shifts to neutral · Check sensor gap at turbine speed
·Low pressure at clutch K4 OP mode : TCU shutdown sensor
·Low main pressure · Check signal at internal speed
·Wrong signal at internal speed sensor sensor
·Wrong signal at turbine speed sensor · Check signal at turbine speed
·Wrong size of the sensor gap sensor
·Clutch is defective Replace clutch

3-45
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
B5 Slippage at clutch KV TCU shifts to neutral · Check pressure at clutch KV
TCU calculates a differential speed at OP mode : Limp home · Check main pressure in the system
closed clutch KV. If this calculated value If failure at another clutch · Check sensor gap at internal speed
is out of range, TCU interprets this as is pending sensor
slipping clutch TCU shifts to neutral · Check sensor gap at turbine speed
·Low pressure at clutch KV OP mode : TCU shutdown sensor
·Low main pressure · Check signal at internal speed
·Wrong signal at internal speed sensor sensor
·Wrong signal at turbine speed sensor · Check signal at turbine speed
·Wrong size of the sensor gap sensor
·Clutch is defective · Replace clutch
B6 Slippage at clutch KR TCU shifts to neutral · Check pressure at clutch KR
TCU calculates a differential speed at OP mode : Limp home Check main pressure in the system
closed clutch KR. If this calculated value If failure at another clutch · Check sensor gap at internal speed
is out of range, TCU interprets this as is pending sensor
slipping clutch TCU shifts to neutral · Check sensor gap at turbine speed
·Low pressure at clutch KR OP mode : TCU shutdown sensor
·Low main pressure · Check signal at internal speed
·Wrong signal at internal speed sensor sensor
·Wrong signal at turbine speed sensor · Check signal at turbine speed
·Wrong size of the sensor gap sensor
·Clutch is defective · Replace clutch
B7 Overtemp sump No reaction · Cool down machine
TCU measured a temperature in the oil OP mode : Normal · Check oil level
sump that is over the allowed threshold. · Check temperature sensor
B8 Overtemp retarder TCU disables retarder · Cool down machine
TCU measured a temperature in the OP mode : Normal · Check oil level
retarder oil that is over the allowed · Check temperature sensor
threshold
B9 Overspend engine Retarder applies
-
OP mode : Normal
BA Differential pressure oil filter No reaction · Check oil filter
TCU measured a voltage at differential OP mode : Normal · Check wiring from TCU to
pressure switch out of the allowed range differential pressure switch
·Oil filter is polluted · C h e ck d i f fe r e n t i a l p r e s s u r e
·Cable/connector is broken or cable/ switch(Measure resistance)
connector is contacted to battery voltage
or vehicle ground
·Differential pressure switch is defective

3-46
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
BB Slippage at converter lockup clutch · Check pressure at converter lockup
TCU calculates a differential speed at clutch
closed converter lockup clutch. If this · Check main pressure in the system
calculated value is out of range, TCU · Check sensor gap at engine speed
interprets this as slipping clutch sensor
·Low pressure at converter lockup clutch · Check sensor gap at turbine speed
·Low main pressure sensor
·Wrong signal at engine speed sensor · Check signal at engine speed
·Wrong signal at turbine speed sensor sensor
·Wrong size of the sensor gap · Check signal at turbine speed
·Clutch is defective sensor
· Replace clutch
BD S.C. to ground at engine brake solenoid No reaction · Check the cable from TCU to
TCU detected a wrong voltage at the OP mode : Normal engine brake solenoid
output pin, that looks like a S.C. to vehicle · Check the connectors from engine
ground brake solenoid to TCU
·Cable is defective and is contacted to · Check the resistance* of engine brake
vehicle ground solenoid
·Engine brake solenoid has an internal * See page 3-52
defect
·Connector pin is contacted to vehicle
ground
BE S.C. to battery voltage at engine brake No reaction · Check the cable from TCU to the
TCU detected a wrong voltage at the OP mode : Normal engine brake solenoid
output pin, that looks like a S.C. to battery · Check the connectors from engine
voltage brake solenoid to TCU
·Cable is defective and is contacted to · Check the resistance* of engine brake
battery voltage solenoid
·Engine brake solenoid has an internal * See page 3-52
defect
·Connector pin is contacted to battery
voltage
BF O.C. at engine brake No reaction · Check the cable from TCU to the
TCU detected a wrong voltage at the OP mode : Normal engine brake solenoid
output pin, that looks like a O.C. for this · Check the connectors from engine
output pin brake solenoid to TCU
·C a b l e i s d e fe c t i ve a n d h a s n o · Check the resistance* of engine brake
connection to TCU solenoid
·Engine brake solenoid has an internal * See page 3-52
defect
·Connector has no connection to TCU

3-47
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
C3 Overtemp converter output No reaction · Cool down machine
TCU measured a oil temperature at the OP mode : Normal · Check oil level
converter output that is the allowed · Check temperature sensor
threshold
C4 S. C. t o g r o u n d a t j oy s t i ck s t a t u s No reaction · Check the cable from TCU to
indicator OP mode : Normal joystick status indicator
TCU detected a wrong voltage at the · Check the connectors from joystick
output pin, that looks like a S.C. to vehicle status indicator to TCU
ground · Check the resistance* of joystick
·Cable is defective and is contacted to status indicator
vehicle ground * See page 3-52
·Joystick status indicator has an internal
defect
·Connector pin is contacted to vehicle
ground
C5 S.C. to battery voltage at joystick status No reaction · Check the cable from TCU to
indicator OP mode : Normal joystick status indicator
TCU detected a wrong voltage at the · Check the connectors from joystick
output pin, that looks like a S.C. to battery status indicator to TCU
voltage · Check the resistance* of joystick
·Cable is defective and is contacted to status indicator
battery voltage * See page 3-52
·Joystick status indicator has an internal
defect
·Connector pin is contacted to battery
voltage
C6 O.C. at joystick status indicator No reaction · Check the cable from TCU to
TCU detected a wrong voltage at the OP mode : Normal joystick status indicator
output pin, that looks like a O.C. for this · Check the connectors from joystick
output pin status indicator to TCU
·C a b l e i s d e fe c t i ve a n d h a s n o · Check the resistance* of joystick
connection to TCU status indicator
·Joystick status indicator has an internal * See page 3-52
defect
·Connector pin has no connection to
TCU

3-48
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
D1 S.C. to battery voltage at power supply See fault codes No.21 to · Check cables and connectors to
for sensors 2C sensors, which are supplied from
TCU measures more than 6V at the pin AU1
AU1 (5V sensor supply) · Check the power supply at the pin
AU1(Should be appx. 5V)
· Fault codes No.21 to No.2C may be
reaction of this fault
D2 S.C. to ground at power supply for See fault codes No.21 to · Check cables and connectors to
sensors 2C sensors, which are supplied from
TCU measures less than 4V at the pin AU1
AU1 (5V sensor supply) · Check the power supply at the pin
AU1(Should be appx. 5V)
· Fault codes No.21 to No.2C may be
reaction of this fault
D3 Low voltage at battery Shift to neutral · Check power supply battery
Measured voltage at power supply is lower OP mode : TCU shutdown · Check cables from batteries to TCU
than 18V(24V device) · Check connectors from batteries to
TCU
D4 High voltage at battery Shift to neutral · Check power supply battery
Measured voltage at power supply is OP mode : TCU shutdown · Check cables from batteries to TCU
higher than 32.5V(24V device) · Check connectors from batteries to
TCU
D5 Error at valve power supply VPS1 Shift to neutral · Check fuse
TCU switched on VPS1 and measured OP mode : TCU shutdown · Check cables from gearbox to TCU
VPS1 is off or TCU switched off VPS1 and · Check connectors from gearbox to
measured VPS1 is still on TCU
·Cable or connectors are defect and are · Replace TCU
contacted to battery voltage
·Cable or connectors are defect and are
contacted to vehicle ground
·Permanent power supply KL30 missing
·TCU has an internal defect
D6 Error at valve power supply VPS2 Shift to neutral · Check fuse
TCU switched on VPS2 and measured OP mode : TCU shutdown · Check cables from gearbox to TCU
VPS2 is off or TCU switched off VPS2 and · Check connectors from gearbox to
measured VPS2 is still on TCU
·Cable or connectors are defect and are · Replace TCU
contacted to battery voltage
·Cable or connectors are defect and are
contacted to vehicle ground
·Permanent power supply KL30 missing
·TCU has an internal defect

3-49
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
E1 S.C. battery voltage at speedometer ※ Not used
-
output
E2 S.C. to ground or O.C at speedometer ※ Not used
-
output
E3 S.C. to battery voltage at display output No reaction · Check the cable from TCU to the
TCU sends data to the display and OP mode : Normal display
measures always a high voltage level on · Check the connectors at the display
the connector · Change display
·Cable or connectors are defective and
are contacted to battery voltage
·Display has an internal defect
E4 S.C. to ground at display output No reaction · Check the cable from TCU to the
TCU sends data to the display and OP mode : Normal display
measures always a high voltage level on · Check the connectors at the display
the connector · Change display
·Cable or connectors are defective and
are contacted to battery voltage
·Display has an internal defect
E5 Communication failure on DeviceNet Shift to neutral · Check Omron master
OP mode : TCU shutdown · Check wire of DeviceNet-Bus
· Check cable to Omron master
E6 DISPID1 timeout TCU select parameter set · Check display controller
Timeout of CAN-massage DISPID1 from with ID0 · Check wire of CAN-Bus
display controller OP mode : Limp home · Check cable display controller
·Interference on CAN-Bus
·CAN wire/connector is defective
·Can wire/connector is defective and has
contact to vehicle ground or battery
voltage

3-50
Fault code Meaning of the fault code Reaction of the TCU Possible steps to repair
(Hex) possible reason for fault detection
F1 General EEPROM fault No reaction · Replace TCU
TCU can't read non volatile memory OP mode : Normal ※ Often shown together with fault
·TCU is defective code F2
F2 Configuration lost Transmission stay neutral · Reprogram the correct configurat-
TCU has lost the correct configuration and OP mode : TCU shutdown ion for the vehicle (e.g. with cluster
can't control the transmission controller,...)
·Interference during saving data on non
volatile memory
·TCU is brand new or from another
vehicle
F3 Application error Transmission stay neutral · Replace TCU
Something of this application is wrong OP mode : TCU shutdown ※ This fault occurs only if an test
engineer did something wrong in
the application of the vehicle
F5 Clutch failure Transmission stay neutral · Check clutch
AEB was not able to adjust clutch filling OP mode : TCU shutdown ※ TCU shows also the affected clutch
parameters on the display
·One of the AEB-Values is out of limit
F6 Clutch adjustment data lost No reaction, · Execute AEB
TCU was not able to read correct clutch Default values : 0 for AEB
adjustment parameters Offsets used
·Interference during saving data on non OP mode : Normal
volatile memory
·TCU is brand new

3-51
5) MEASURING OF RESISTANCE AT ACTUATOR/SENSOR AND CABLE
(1) Actuator

2 G
76043PT19

Open circuit R12 = R1G = R2G =

Short cut to ground R12 = R; R1G = 0, R2G = R or R1G = R, R2G = 0
(For S.C. to ground, G is connected to vehicle ground)
Short cut to battery R12 = R; R1G = 0, R2G = R or R1G = R, R2G = 0
(For S.C. to battery, G is connected to battery voltage)

(2) Cable
UBat

P(Power supply)
TCU
1 2 Actuator/
Sensor

C(Chassis)

Ground
76043PT20

Open circuit R12 = R1P = R1C = R2P = R2C=

Short cut to ground R12 = 0; R1C = R2C = 0, R1P = R2P =
Short cut to battery R12 = 0; R1C = R2C = 0, R1P = R2P = 0

3-52
5. AXLE
1) OPERATION
· The power from the engine passes through torque converter, transmission and drive shafts, and is
then sent to the front and rear axles.
· Inside the axles, the power passes from the bevel pinion to the bevel gear and is sent at right
angles. At the same time, the speed is reduced and passes through the both differentials to the
axle shafts. The power of the axle shafts is further reduced by planetary-gear-type final drives and
is sent to the wheels.
(1) Front axle

3
2 2
3

78093PT14

1 Input 2 Output 3 Brake

4 Axle housing

(2) Rear axle

4
1

3
2 2
3

78093PT15

1 Input 2 Output 3 Brake

4 Axle housing 5 Axle drive housing

3-53
2) DIFFERENTIAL

(1) Description 3
When the machine makes a turn, the
2 4
outside wheel must rotate faster than the
inside wheel. A differential is a device
which continuously transmits power to the
right and left wheels while allowing them
to turn a different speeds, during a turn.
The power from the drive shaft passes
through bevel pinion (1) and is transmitted
to the bevel gear (2). The bevel gear
changes the direction of the motive force
by 90 degree, and at the same time
reduces the speed. 1
It then transmits the motive force through
the differential (3) to the axle gear shaft 770-3 [3-26(1)]

(4).

(2) When driving straight forward

Pinion gear
When the machine is being driven straight
Side gear Side gear
forward and the right and left wheels are
rotating at the same speed, so the pinion Axle gear shaft
gear inside the differential assembly do
not rotate. The motive force of the carrier
is send through the pinion gear and the
side gear, therefore the power is equally Carrier
transmitted to the left and right axle gear Pinion gear
shaft.

770-3 [3-26(2)]

(3) When turning

Swing
When turning, the rotating speed of the
Pinion gear
left and right wheels is different, so the
Side gear Side gear
pinion gear and side gear inside the
differential assembly rotate in accordance
with the difference between the rotating
speed of the left and right wheels.
T h e p owe r o f t h e c a r r i e r i s t h e n
transmitted to the axle gear shafts. Carrier

Pinion gear Ring gear

770-3 [3-26(3)]

3-54
3) TORQUE PROPORTIONING DIFFERENTIAL
(1) Function
① Because of the nature of their work,
4-wheel-drive loaders have to work in
places where the road surface is bad.
In such places, if the tires slip, the ability
to work as a loader is reduced, and also
the life of the tire is reduced.
The torque proportioning differential is
installed to overcome this problem.
In structure it resembles the differential of
an automobile, but the differential pinion
gear has an odd number of teeth.
Because of the difference in the
resistance from the road surface, the
position of meshing of the pinion gear
and side gear changes, and this
changes the traction of the left and right
tires.

(2) Operation
Spider rotating
① When traveling straight direction
(Equal resistance from road surface to
left and right tires)
Under this condition, the distances
involving the engaging points between
FL FR
right and left side gears and pinion-a and Engaging a b Engaging
point point
b-are equal and the pinion is balanced
as FL×a=FR×b. Thus, FL=FR, and
the right and left side gears are driven Left side gear Right side gear
with the same force. Pinion
770-3 (3-27)

3-55
② When traveling on soft ground
(Resistance from road surface to left and
right tires is different)
If the road resistance to the left wheel is
Spider rotating
smaller, the left side gear tends to rotate direction
forward, and this rotation changes the
engaging points between the side gears
and pinion. As a result, the distances
involving the engaging points becomes FL
Small road FR Large road
a>b. The pinion now is balanced as resistance a b resistance
FL×a=FR×b, where FL>FR. The right Engaging Engaging
side gear is driven with a greater force point point
than the left side gear. The torque can
Left side gear Right side gear
be increased by up to about 30% for Pinion
either side gear.
The pinion therefore does not run idle
and driving power is transmitted to both
side gears until the difference between
road resistance to the right and left
(770-7)3-27
wheels reaches about 30%.

3-56
6. TIRE AND WHEEL

7407APT10

1 Wheel rim 3 O-ring 5 Side ring

2 Tire 4 Lock ring 6 Valve assembly

1) The tire acts to absorb the shock from the ground surface to the machine, and at the same time
they must rotate in contact with the ground to gain the power which drives the machine.
2) Various types of tires are available to suit the purpose. Therefore it is very important to select the
correct tires for the type of work and bucket capacity.

3-57
GROUP 2 OPERATIONAL CHECKS AND TROUBLESHOOTING

1. POWER TRAIN OPERATIONAL CHECKS

This procedure is designed so that the mechanic can make a quick check of the system using a
minimum amount of diagnostic equipment. If you need additional information, read Structure and
function, Group 1.
A location will be required which is level and has adequate space to complete the checks.
The engine and all other major components must be at operating temperature for some checks.
Locate system check in the left column and read completely, following the sequence from left to right.
Read each check completely before performing.
At the end of each check, if no problem is found (OK), that check is complete or an additional check
is needed. If problem is indicated (NOT OK), you will be given repair required and group location.
If verification is needed, you will be given next best source of information :

Chapter 2 : Troubleshooting
Group 3 : Tests and adjustments

3-58
ö
Transmission
ö
Transmission oil must be at operating temperature for these checks.

Item Description Service action

Transmission oil warm-up Start engine. Apply service brakes OK
procedure and release parking brake. Check completed.
Select T/M shift mode switch to
MAN (manual) mode.
Move gear selector lever to 3rd
speed.
Move gear selector lever to forward
"F" position.
Increase engine speed to high idle
AL MAN

for 30 seconds.
AN AH
A
Move gear selector lever to neutral
"N" position and r un for 15
seconds.
1

4
2
3
Repeat procedure until
transmission temperature gauge
arrow points to bar above dial.
Gear selector lever and Move gear selector lever to each OK
neutral lock latch checks position. Check completed.
Engine OFF. 1

NOTE : Gear selector lever position

2
3
4

NOT OK
changes slightly as steer ing
Repair lock or replace
column is tilted.
switch.
FEEL : Lever must move freely
through all positions.
Engage neutral lock.
Apply slight effort to move lever into
forward (F) and reverse (R).
LOOK : Neutral lock must stay
engaged.
Automatic shifting check Start engine. OK
Check completed.
1
2
3
F
N
Move gear selector lever to 4th
4
R
speed.
NOT OK
Turn T/M shift mode switch to AL Go to transmission error
(auto light) mode. code group at page 3-32~
3-51.
Auotmatic sign LOOK : Automatic sign on monitor.
Repair or replace the
Move gear selector lever to forward monitor or harness.
or reverse position.
Increase engine rpm.
LOOK : Speed on monitor must
vary with machine speed.

3-59
 Item Description Service action
Transmission noise Run engine at approximately 1600 OK
check 1
2
rpm. Check completed.
3

Engine running.
4

Drive unit with transmission in each NOT OK

forward and reverse speed. Go to transmission makes
excessive noise, chapter 2
LISTEN : Transmission must not
in this group.
make excessive noise in any range.
Engine rpm must not "lug down" as
unit is shifted between gears.
Transmission "quick shift" Release parking brake and select OK
Release
check T/M shift mode switch to MAN Check completed.
Engine running. (manual) mode.
NOT OK
P

Shift to 2nd forward. Check connector at base

of control valve.
Drive machine at approximately
5km/h and press gear selector lever IF OK
kick down switch or RCV levers Go to transmission
switch once. controller circuit in group 1.
AL MAN

LOOK/FEEL : Transmission must

AN
A
AH
shift to and remain in 1st gear.
Press gear selector lever kick down
switch once.
1

4
2
3
LOOK/FEEL : Transmission must
shift back to 2nd gear.
Shift to (3rd or 4th) gear and press
gear selector lever kick down
switch once.
LOOK/FEEL : Transmission must
not shift down.
Select T/M shift mode switch to AL
(auto light) mode.
Drive machine at approximately
90 speed of max speed in each
gear (2nd or 3rd or 4th).
Shift to (2nd or 3rd or 4th) gear in
each forward and reverse speed
and press gear selector kick down
lever switch or RCV lever switch
once.
LOOK/FEEL : It shift down quickly
from current gear to one step lower
speed and recover to original
speed quickly when push the
switch one more time. (mode 1)

3-60
 Item Description Service action
LOOK/FEEL : If shifts down from
current gear to one step lower
speed when push the switch
everytime and recover when push
the switch in 1st gear. (mode 2)
Forward, reverse and 4th Park unit on level surface. OK
speed clutch pack drag 1
2
3 Check completed.
Apply service brakes.
4

check
NOT OK
ö Transmission must Move gear selector lever to neutral.
I f u n i t m ove s, r e p a i r
be warmed up for Release
Move gear selector lever to 1st. transmission.
this check.
Engine running. Release parking brake and service
P

brakes.
Run engine at low idle.
LOOK : Unit must not move in
either direction.
NOTE : If unit moves forward,
either the forward pack or the 4th
speed pack is dragging.
Transmission shift Run engine at approximately 1300 OK
modulation check 1

4
2
3 rpm. Check completed.
Engine running.
Put transmission in 1st forward, NOT OK
shift several times from forward to Go to unit shifts too fast,
reverse and reverse to forward. chapter 2 in this group.
Repeat check in 2nd gear.
LOOK : Unit must slow down and
change direction smoothly.
Torque converter check Start engine. Apply service brakes OK
1

4
2
3
and release parking brake. Check completed.
Move gear selector lever to 3rd NOT OK
speed. If stall rpm are too low or
too high, problem may be
Move gear selector control lever to
engine power or torque
forward "F" position.
converter.
Increase engine speed to high idle.
IF OK
LOOK : Torque converter stall rpm Replace transmission
must be within the following range. torque converter.
Stall rpm : 2030Ü70 rpm
Move gear selector control lever to
neutral "N" position and run for 15
seconds.

3-61
2. TROUBLESHOOTING
1) TRANSMISSION
ö Diagnose malfunction charts are arranged from most probable and simplest to verify, to least likely,
more difficult to verify. Remember the following steps when troubleshooting a problem :
Step 1. Operational check out procedure (See group 3 in section 1.)
Step 2. Operational checks (In this group.)
Step 3. Troubleshooting
Step 4. Tests and/or adjustments (See group 3.)

Problem Cause Remedy

Transmission slippage Low oil level. Add oil.
Wrong oil grade. Change oil.
Restricted transmission pump Remove and clean screen.
suction screen.
Leak in transmission control valve Remove valve and inspect gaskets.
or gasket.
Low transmission pump flow due Do transmission pump flow test.
to worn pump.
W e a k o r b r o k e n p r e s s u r e Do transmission system pressure test.
regulating valve spring.
Error code on display Something wrong in transmission. Go to transmission error code group at page
3-32~3-51.

3-62
 Problem Cause Remedy
Machine will not move Low oil level. Add oil.
Applied park brake. Check parking brake fuse.
Check continuity to parking brake switch.
N o p o w e r t o t r a n s m i s s i o n Check transmission controller fuse.
controller.
Malfunctioning parking brake Remove and inspect parking brake solenoid
solenoid valve. valve.
Check for power to solenoid valve.
Restricted orifice of PPC valve. Remove orifice and check for contamination
and/or plugging.
(Do not remove valve housing for this purpose.)
Excessive leakage in Do transmission element leakage test using
transmission element. system pressure.
Worn clutch disks. Repair transmission.
Low or no transmission See transmission pressure is low in this group.
pressure.
Service brake will not release. Do brake pedal operational check.
Do service and park system drag checks.
Failed torque converter. Do torque converter stall test.
If engine pulldown in normal, torque converter is
good.
Broken shafts or gears. Drain transmission to determine if large pieces
of metal contamination are present.
Broken drive shafts. Inspect drive shafts and universal joints for
external damage. Repair.

Broken ring or pinion gear. If drive shaft rotate with transmission in gear but
machine does not move, a differential failure is
indicated. Repair.
Machine does not Malfunctioning transmission Check solenoid valve.
engage in low gear control solenoid valve.
Stuck spool in transmission Remove and inspect transmission control valve
control valve. spools.
Stuck PPC valve. Remove end cover to inspect PPC valve.
Replace if necessary.
Malfunctioning transmission Check speed sensor.
speed sensor.

3-63
 Problem Cause Remedy
Transmission pressure is Low oil level. Check transmission oil level and refill if
low (all gears) necessary.
Failed transmission pressure Verify transmission system pressure. Do
switch. transmission system pressure test.
Plugged suction strainer. Transmission pump may be noisy if transmission
suction screen is clogged. Drain transmission.
Remove and clean suction screen.
Also, check condition of transmission filter.
Stuck transmission pressure Remove transmission pressure regulating valve.
regulating valve or broken spring. Inspect for damage (See transmission control
valve).
Failed control valve gasket. Inspect transmission control valve for external
leakage. Remove control valve.
Inspect or replace gasket.
Stuck PPC valve. Remove end cover to inspect modulation spool
and check torque on cap screws retaining
control valve to transmission.
Tr a n s m i s s i o n s y s t e m Failed transmission pump. Do pump flow test.
pressure is low (one or
Failed transmission control valve Inspect transmission control valve for external
two gears)
gasket. leakage. Remove control valve.
Inspect or replace gasket.
Leakage in clutch piston or seal Disassemble and repair.
ring.
Transmission shifts too Low oil level (aeration of oil). Add oil.
low
Low transmission pressure. Do transmission system pressure test.
Restricted transmission pump Remove and clean screen.
suction screen.
Low transmission pump flow. Do transmission pump flow test.
Excessive transmission Do transmission element leakage test using
element leakage. system pressure.
Stuck PPC valve. Remove end cover to inspect modulation spool.
Replace if necessary.
Restricted PPC valve orifice. Remove orifice and inspect for contamination
and /or plugging.
Restricted oil passages between Remove control valve and inspect oil passage.
control valve and transmission
elements.
Incorrect transmission oil. Change oil (SAE 10W-30/15W-40)

3-64
 Problem Cause Remedy
Transmission shifts too Wrong transmission controller. Check if transmission controller has been
fast changed
System pressure too high. Do transmission system pressure test.
Stuck PPC valve. Remove and inspect PPC valve.
Replace if necessary. Also remove end cover
to inspect PPC valve and control valve housing.
Replace if necessary.
Stuck or missing check valves. Inspect transmission control valve.
Missing O-r ing from end of Remove orifice and inspect port for O-ring.
modulation orifice.
Broken piston return spring. Disassemble and inspect clutch.
Incorrect transmission oil. Change oil (SAE 10W-30/15W-40).
Machine "creeps" War ped disks and plates in Check transmission.
in neutral transmission.
Transmission hydraulic High oil level. Transmission overfilled or hydraulic pump seal
system overheats leaking.
Low oil level. Add oil.
Wrong oil grade. Change oil.
Park brake dragging. Check for heat in park brake area.
Pinched, restricted or leaking lube Check cooler lines.
lines.
Machine operated in too high Operate machine in correct gear range.
gear range.
Malfunction in temperature gauge I n s t a l l t e m p e ra t u r e s e n s o r t h e ve r i f y
or sensor. temperature.
Do tachometer/temperature reader installation
procedure.
Restricted air flow through oil Do radiator air flow test.
cooler or radiator.
Failed oil cooler bypass valve (In Disassemble and inspect.
thermal bypass valve).
Failed thermal bypass valve. Remove thermal bypass valve and check to see
if machine still overheats. Do transmission oil
cooler thermal bypass valve test.
Internally restricted oil cooler. Do oil cooler restriction test.
Leakage in transmission hydraulic Do transmission system pressure, element
system. leakage test.
Malfunction in converter relief Do converter out pressure test.
valve.
Low transmission pump output. Do transmission pump flow test.

3-65
 Problem Cause Remedy
Excessive transmission Too low engine low idle. Check engine low idle speed.
noise (Under load or no
Wo r n p a r t s o r d a m a g e d i n Remove transmission suction screen. Inspect
load)
transmission. for metal particles.
Repair as necessary.
Warped drive line between engine Inspect drive line.
and torque converter.
Low or no lube. Do converter-out and lube pressure test. Do
transmission pump flow test.
Foaming oil Incorrect type of oil. Change oil.
High oil level. Transmission overfilled or hydraulic pump seal
leaking.
Low oil level. Add oil.
Air leak on suction side of pump. Check oil pickup tube on side of transmission.
Oil ejected from dipstick Plugged breather. Inspect breather on top of transmission.
Replace.
Machine vibrates Aerated oil. Add oil.
Low engine speed. Check engine speed.
Fa i l e d u n i ve r s a l j o i n t s o n Check universal joints.
transmission dr ive shaft or
differential drive shafts.
Machine lacks power and Engine high idle speed set too Check high idle adjustment.
acceleration low.
Incorrect transmission oil. Change oil.
Aerated oil. Add oil.
Low transmission pressure. Do transmission system pressure test.
Warped transmission clutch. Do transmission clutch drag checks.
Torn transmission control valve Inspect gasket.
gasket.
Brake drag. Do brake drag check.
Failed torque converter. Do torque converter stall speed test.
Low engine power. Do engine power test.
Torque conver ter stall Aerated oil. Put clear hose on thermal bypass outlet port.
RPM too high Run machine to check for bubbles in oil.
Stuck open converter relief valve. Do converter-out pressure test.
Leakage in torque converter seal. Do converter-out pressure test.
Torque converter not Replace torque converter.
transferring power (Bent fins,
broken starter).

3-66
 Problem Cause Remedy
Torque conver ter stall Low engine power. Do engine power test.
RPM too low
Mechanical malfunction. Remove and inspect torque converter.
Transmission pressure Low oil level. Add oil.
light comes ON when
Cold oil. Warm oil to specification.
shifting from forward to
reverse (all other gears Leak in reverse pack. Do transmission pressure, pump flow, and
OK) leakage check.
Transmission pressure Cold oil. Warm oil to specification.
light comes ON for each
No time delay in monitor. Do monitor check.
shift
Restriction in modulation orifice. Remove orifice and inspect for restriction and/or
plugging.
Stuck PPC valve. Remove and inspect.
Low transmission pressure circuit. Do transmission system pressure test.

Leak in transmission pressure Do converter out pressure test.

circuit.
Failed transmission pump. Do transmission pump flow test.
Clogged filter. Inspect filter. Replace.

3-67
 2) DIFFERENTIAL / AXLE
Problem Cause Remedy
Differential low on oil External leakage. Inspect axle and differential for leaks.
Excessive differential Low oil level in differential. Check oil. Remove drain plug and inspect for
and/or axle noise metal particles in differential case.
Disassemble and determine cause.
Incorrect type of oil. Change oil
Dragging brakes. Do brake check.
Failed pinion bearing. Remove and inspect pinion.
Check to ensure pinion housing was indexed.
Incorrect gear mesh pattern Remove pinion gear housing and inspect ring
between ring and pinion gear. and pinion gear.
Failed differential pinion gears Remove differential housing drain plug and
and/or cross shafts. inspect for metal particles. Disassemble and
inspect.
Failed axle bearing. Do axle bearing adjustment check.
M e c h a n i c a l fa i l u r e i n a x l e Remove differential. Inspect, repair.
planetary.
Oil seeping from outer Excessive end play in axle. Do axle bearing adjustment check.
axle seal
Worn outer bearing and/or cup. Disassemble and inspect outer axle bearing,
cup, spacer, and seal. Replace, if necessary.
Overfilled differential. Check differential oil return system for
excessive internal restriction.
Axle overheats Low differential oil. Add oil.
Overfilled differential. See differential overfills with oil in this group.
Brake drag. See brakes drag in this group.

3) DRIVE LINE
Problem Cause Remedy
E x c e s s i v e d r i v e l i n e Yokes not in line on drive shafts. Inspect. Align drive shaft yokes.
vibration or noise
Worn front drive line support Inspect, repair.
bearing.
Bent drive shaft. Inspect all drive shafts. Replace.
Loose yoke retaining nuts (drive Inspect. Replace.
shafts wobble at high speed).
Rear axle oscillating support. Inspect, repair.
Lack of lubrication. Lubricate with proper grade of grease.

3-68
GROUP 3 TESTS AND ADJUSTMENTS

1. TRANSMISSION MEASURING POINTS AND CONNECTIONS

The measurements have to be carried out at hot transmission (about 80~95˚C).
21 47 48 27 16 34
A

55 60 56 53 58

52 63

57
10 D C

E B

F A 65
29 K
H
51

15
VIEW B

49 33 28
VIEW A 78093PT17

1) OIL PRESSURE AND TEMPERATURE

Port Description Size
51 In front of the converter-opening pressure (11bar) H M10×1.0
52 Behind the converter-opening pressure (5bar) M14×1.5
53 Forward clutch (16+2bar) KV B M10×1.0
55 Reverse clutch (16+2bar) KR F M10×1.0
56 1st clutch (16+2bar) K1 D M10×1.0
57 2nd clutch (16+2bar) K2 A M10×1.0
58 3rd clutch (16+2bar) K3 C M10×1.0
60 4th clutch (16+2bar) K4 E M10×1.0
63 Behind the converter temperature 100˚C, short-time 120˚C M14×1.5
65 System pressure (16+2bar) K M10×1.0

3-69
2) DELIVERY RATES
Port Description Size
10 Breather M10×1.0
15 Connection to the oil cooler -
16 Connection from the oil cooler -
27 Connection to the filter M42×2.0
28 Connection from the filter M42×2.0
29 Connection from the filter bypass M42×2.0
33 Connection oil filler plug M42×2.0
49 Plug connection on the electro-hydraulic control unit -

3) INDUCTIVE TRANSMITTER AND SPEED SENSOR

Port Description Size
21 Inductive transmitter n Turbine M18×1.5
34 Speed sensor n Output and speedometer -
47 Inductive transmitter n Central gear train M18×1.5
48 Inductive transmitter n Engine M18×1.5

3 - 70
GROUP 4 DISASSEMBLY AND ASSEMBLY

1. CONTROL VALVE
1) DISASSEMBLY
(1) Loosen the cap screws and take off the
gear shift housing.
※ Special tool
Socket spanner TX-27 5873 042 002

Figure 1001

(2) Separate the hose lines from the duct

plate. Loosen the cap screws as well as
the gasket from the transmission housing.
※ Special tool
Socket spanner TX-40 5873 042 004

Figure 1002

(3) Mark the installation position of the wiring

harness to the valve block.

Figure 1003

(4) Loosen the cap screws.

Separate duct plate and intermediate
plate from the valve block.

Figure 1004

3-71
(5) Remove the retaining clamp

Figure 1005

(6) Loosen the cap screws and take off the

cover.
Remove the opposite cover.
※ Special tool
Socket spanner TX-27 5873 042 002

Figure 1006

(7) Remove the wiring harness.

Figure 1007

(8) Loosen the cap screws, remove the fixing

plates and the pressure controllers.
※ Special tool
Socket spanner TX-27 5873 042 002

Figure 1008

3-72
(9) Loosen two cap screws and fasten the
housing preliminarily by means of
adjusting screws (housing is preloaded).
Then loosen the remaining cap screws.
※ Special tool
Adjusting screws 5870 204 036

Figure 1009

(10) Separate the housing from the valve

housing by equally loosening the
adjusting screws.
※ Special tool
Adjusting screws 5870 204 036

Figure 1010

(11) Remove the single components.

Figure 1011

(12) Remove the opposite pressure controllers,

the housing as well as single components
analogously.

Figure 1012

3-73
2) ASSEMBLY
※ All single components are to be checked for
damage and replaced, if required.
Prior to installation check the mobile parts
in the housing for functionality.
Pistons can be replaced individually.
Oil the single components pr ior to
installation.
Place the orifices, with the concave side
showing upwards, until contact.
※ Installation position, see arrows. Figure 1013

(1) Opposite figure shows the following single

components.
1 Vibration damper
(3EA, piston & comp spring)
2 Follow-on slide
(3EA, piston & comp spring)
3 Pressure reducing valve 3
(1EA, piston & comp spring) 1 1
2 2

Figure 1014

(2) Install the single components according to

figure 1014.
※ Preload the compression springs of the
follow-on slides and fasten the pistons
preliminarily by means of cylindrical pins
Ø5.0 mm (assembly aid), see arrows/
figure 1015.

Figure 1015

(3) Install two adjusting screws.

Assemble gasket (arrow) and housing
cover (figure 1016).
Then place the housing cover by means
of adjusting screws equally until contact
(figure 1017).
※ Special tool
Adjusting screws 5870 204 036

Figure 1016

3-74
 Figure 1017

(4) Preload the pistons and remove the

adjusting screws (assembly aid) again.

Figure 1018

(5) Fasten the housing cover with cap screws.

·Torque limit : 0.76 kgf·m (5.53 lbf·ft)
※ Special tool
Socket spanner TX-27 5873 042 002

Figure 1019

(6) Assemble the pressure controllers and

fasten them by means of fixing plates and
cap screws.
※ Install the fixing plate with the neck
showing downwards.
Observe radial installation position of the
pressure controllers, see Figure.
·Torque limit : 0.56 kgf·m (4.06 lbf·ft)

Figure 1020

3-75
Preassemble the opposite side :
(7) The opposite figure shows the following
single components :
1 Main pressure valve
(1EA, piston & comp spring)
2 Follow-on slide
(3EA, piston & comp spring) 3 1
3 Vibration damper 3
(3EA, piston & comp spring)
2 2
Figure1021

(8) Install the single components according to

figure 1021.
Preload the compression springs of the
follow-on slides and fasten the piston
preliminarily by means of cylindrical pins
Ø5 mm (assembly aid), see arrows.
Install two adjusting screws.
Assemble the gasket (arrow 1) and the
housing cover and place them equally
until contact by means of adjusting Figure1022
screws.
Then fasten the housing cover with cap
screws.
·Torque limit : 0.76 kgf·m (5.53 lbf·ft)
Remove the cylindrical pins (assembly
aid) again.
※ Special tool
Adjusting screws 5870 204 036

(9) Assemble the pressure controllers and

fasten them by means of fixing plates and
cap screws.
※ Install the fixing plates with the neck
showing downwards.
Observe radial installation position of the
pressure controllers, see Figure.
·Torque limit : 0.56 kgf·m (4.06 lbf·ft)
※ Special tool
Socket spanner TX-27 5873 042 002 Figure1023

3-76
(10) Assemble the wiring harness and connect
the pressure controllers (6EA).
※ Pay attention to the installation position of
the wiring harness, also see markings
(figure 1003).

Figure1024

(11) Put on the flat gasket (arrow).

Assemble the plug socket with the slot
showing to the lug of the cover until
contact.
Fasten the cover by means of cap screws.
·Torque limit : 0.76 kgf·m (5.53 lbf·ft)

Figure1025

(12) Fasten the plug socket a retaining clamp.

Install the opposite cover.

Figure 1026

(13) Screens (6EA) are to be flush mounted

into the bores of the intermediate sheet,
see arrows.
※ Observe the installation position-the
screens are showing upwards (to the duct
plate)

Figure1027

3-77
(14) Install two adjusting screws.
Place the intermediate sheet with the
screens showing upwards.
※ Sepcial tool
Adjusting screws 5870 204 063

Figure1028

(15) Put on the duct plate and fasten it equally

by means of cap screws.
·Torque limit : 0.97 kgf·m (7.01 lbf·ft)
※ Special tool
Socket spanner TX-27 5873 042 002

Figure1029

(16) Provide the screw plugs (8EA) with new

O-rings and install them.
·Torque limit : 0.61 kgf·m (4.43 lbf·ft)

Figure1030

Preassemble the duct plate (figure 1031)

(17) Install connection pipes 1~4.
Install screw plugs 5 and 6. 1
·Torque limit
Plug (M10×1) : 0.61 kgf·m (4.43 lbf·ft)
Plug (M14×1.5) : 4.08 kgf·m (29.5 lbf·ft)
6 3 2
※ Always install new O-rings. 4
5

Figure1031

3-78
Installation of the Hydraulic Control Unit
(HCU-94)(figure1032~1036) :
(18) Provide the screw plug with a new O-ring
and install it.
·Torque limit
M26×1.5 : 8.16 kgf·m (59.0 lbf·ft)

Figure 1032

(19) Install two adjusting screws.

Put on the gasket (arrow).
※ Special tool
Adjusting screws M8 5870 204 011

Figure 1033

(20) Put on the duct plate and fasten it equally

by means of cap screws.
·Torque limit
M8/10.9 : 2.35 kgf·m (16.7 lbf·ft)
※ Special tool
Socket spanner TX-40 5873 042 004
Torque spanner Slipper 5870 203 043

Figure 1034

(21) Install 2 adjusting screws (M6).

Put on the gasket (arrow).
※ Special tool
Adjusting screws M6 5870 204 063

Figure 1035

3-79
(22) Fasten the complete valve block equally
by means of cap screws (6pcs. M6×100 &
17pcs. M6×76 mm).
Observe position of the cap screws
(M6×100),
(M6 100), see arrow.
·Torque limit : 1.22 kgf·m (8.85 lbf·ft)
※ Special tool
Socket spanner TX-27 5873 042 002
Torque spanner slipper 5870 203 043
Figure 1036

Following to this all pressure lines are to

be installed.
※ Installation of the lines differs depending
on the version.
Observe the parts list of parts manual.

3-80
2. TRANSMISSION
1) DISASSEMBLY
(1) Fasten the complete transmission to the
assembly truck.
※ Special tool
Assembly truck 5870 350 000
Holding fixture 5870 350 071

Figure 1

(2) Remove the plug (arrow) and drain the oil.

Then remove the oil cylinder.

Figure 2

(3) Remove all oil pipes, the complete gear

shift system and the duct plate.

Figure 3

Converter drive
(1) By means of the lifting tackle separate the
torque converter from the transmission.
※ Special tool
Eybolts assortment 5870 204 002
Lifting chain 5870 281 047

Figure 4

3-81
(2) Loosen the bolt connection and by means
of the forcing screws (3EA) separate the
cover from the converter bell.
※ Special tool
Forcing screws 5870 204 005

Figure 5

(3) By means of the extractor pull the oil

supply flange out of the converter bell.
※ Special tool
Extractor 5870 000 089

Figure 6

(4) Remove the converter safety valve (arrow

1), if required.
※ Converter safety valve is fixed by means
of slotted pin (arrow 2).

Figure 7

(5) Loosen the bolt connection (M8 and M12)

and by means of lifting tackle and pry bar
set separate the coverter bell from the
transmission housing.
※ Special tool
Eyebolts assortment 5870 204 002
Pry bar set 5870 345 036
Lifting chain 5870 281 047

Figure 8

3-82
(6) Remove the rectangular ring (arrow).

Figure 9

(7) Press the input shaft out of the spur gear

bearing. Remove the released bearing
inner ring and the spur gear.

Figure10

(8) Press off the bearing inner ring from the

spur gear.

Figure11

(9) Remove the converter pressure back-up

valve.

Figure 12

3-83
(10) Remove the inductive transmitter.
9 = n - Engine

Figure 13

Input shaft-pump/power take-off (the 1st

power take-off)
(1) Loosen the cap screw.

Figure 21

(2) Remove the cap screw and clamping

plate.

Figure 22

(3) Press the input shaft out of the bearing.

※ Pay attention to released input shaft as
well as shims.
※ Special tool
Extractor 5870 000 065

Figure 23

3-84
(4) Snap out the rectangular ring (arrow 1)
and remove both shims (arrow 2).
1 2

Figure 24

Transmission pump
(1) Loosen the cap and hexagon screws
(depending on the version) respectively
and separate the pump flange from the
housing.

Figure 25

(2) Loosen the cap screws (4EA / M8).

Position the extractor on the transmission
pump and fasten it by means of screws
(M8×65) to the transmission pump. Then
pull out the pump from the housing bore.
※ Extracting is supported by slightly tapping
onto the transmission housing.
※ Special tool
Extractor 5870 000 089
Figure 26

Remove the bearing outer ring (2nd/3rd

and 4th power take-off)
(3) Pull out the bearing outer ring from the
bore.
※ Special tool
Internal extractor 5870 300 017
Counter-support 5870 300 009

Figure 27

3-85
Remove the ball bearing and the driver
(1st power take-off, figure 28~29)
(4) Snap out the retaining ring.

Figure 28

(5) Press out the driver with ball bearing from

the bearing bore.
Then separate the ball bearing from the
driver.

Figure 29

(6) Loosen the cap screws, take off the pump

cover and remove the rotor set.
If marks due to running-in are found on
the pump housing or housing cover, the
complete pump is to be replaced.
Then assemble the rotor set with the
chamfer on the tooth tip showing
downwards and install the housing cover
again.
Figure 30

·Torque limit (M8/8.8) :

2.35 kgf·m (17.0 lbf·ft)
·Torque limit (M6/8.8) :
0.97 kgf·m (7.01 lbf·ft)

3-86
3rd/and 4th power take-off
(7) Remove the screw-in sleeve (arrow).

Figure 31

(8) Sealing cap is to be drilled centrically and

thread M8 to be cut.
By means of the striker expel the sealing
cap from the housing bore.

Figure 32

(9) By means of the striker expel the pin from

the housing bore (figure 33) and remove
the complete spur gear (figure 34).
Striker 5870 650 001

Figure 33

Figure 34

3-87
(10) Loosen the hexagon screws and remove
the cover.

Figure 35

(11) Remove the pump flange on the rear side

and snap out the retaining ring.
Clamping pliers 5870 900 021

Figure 36

(12) Expel the driver from the bearing bore

a n d r e m o ve t h e r e l e a s e d s i n g l e
components.
Plastic hammer 5870 280 004

Figure 37

3-88
Layshaft
(1) Remove the sealing cover and loosen the
hexagon screw.

Figure 38

(2) Expel the idler shaft by means of the

striker from the housing bore and layshaft
bearing respectively.

Figure 39

Removal of inductive and speed transmitt-

er (figure 40~41)
14 = n - Turbine
5 = n - Internal speed input 15
14
13 = n - Output (speed transmitter)

Figure 40

13

Figure 41

3-89
Output
Converter side :
Remove the lock plate. Loosen hexagon
screws and take off the output flange.
Rotate the housing by 180˚ and remove
the output flange on the housing rearside.

Figure 42

Transmission rearside
For working on the brake system observe
the instructions and specifications of the
brake manufacturer.
(1) Unscrew the screw cap.

Figure 43

(2) Loosen the counternut and unscrew the

adjusting screw in counterclockwise
direction until the brake disc is released.

Figure 44

(3) Loosen the cap screws and separate the

complete brake from the transmission
housing.
Remove the lock plate. Loosen the
hexagon screws and separate the output
flange/brake disc from the output shaft.
※ (S) Socket spanner 5870 656 047

Figure 45

3-90
Removal of the clutches and layshaft
(1) Loosen the hexagon screws and expel the
bearing cover KV/K1 by means of the
striker from the housing bore.
Remove the bearing cover KR/K2 (arrow)
analogously.
※ Mark the installation location of the
bearing cover.
※ Special tool Figure 46

Threaded insert 5870 204 069

Striker 5870 650 014

(2) Pull out the bearing cover K4/K3 by

means of the forcing screws from the
housing bore.
※ Special tool
Forcing screws 5870 204 005

Figure 47

(3) Separate the bearing inner ring from

bearing cover K4/K3.
※ Special tool
Three-armed puller 5870 971 003

Figure 48

(4) Loosen the bolt connection.

Separate the housing cover from the
housing by equally tightening both forcing
screws (arrow 1 and 2) as well as the 3 1
threaded spindle (arrow 3). 2

※ Special tool
Internal hex spanner, size 8 5870 290 003
Forcing screws 5870 204 005
Lifting tackle 5870 281 061
Figure 49

3-91
(5) Expel the output shaft from the output
gear.

Figure 50

(6) Loosen the hexagon screws and remove

the oil baffle.
Lift the output gear out of the transmission
housing (figure).
※ Special tool
Stop washer 5870 100 054
Eyebolts assortment 5870 204 002

Figure 51

(7) Remove the bearing inner ring from the

output gear.
※ Special tool
Three-armed puller 5870 971 003

Figure 52

(8) Take the roller bearing out of the housing

bore and remove the oil baffle (arrow).

Figure 53

3-92
Remove the multi-disc clutches
※ For removal of the single clutches observe
the following sequence :
K4/K3 → KR/K2 → KV/K1.
For removal of clutch K4/K3, lift the clutch
KR/K2 slightly and move it in direction of
the arrow, see figure.
※ Special tool
Eyebolts assortment 5870 204 002
Figure 54

(9) Opposite figure shows the clutches when

removed.

K3 K2 K1

K4 KR KV

Figure 55

(10) Remove the layshaft gear.

Figure 56

3-93
Dismantling of the Multi-Disc Clutch K3/K4
(1) By means of clamping ring (S) fasten the
clutch to the assembly truck.
※ Special tool
Clamping ring 5870 654 033

Figure 62

(2) Pull off the roller bearing from the disc

carrier.
※ Special tool
Three-armed puller 5870 971 002

Figure 63

(3) Separate spur gear K3 from the disc

carrier.

Figure 64

(4) Pull off the bearing inner ring from the

disc carrier.
※ Special tool
Rapid grip 5873 012 012
Basic tool 5873 002 001

Figure 65

3-94
(5) Squeeze out the snap ring.
Remove the end shim and disc set K3.

Figure 66

(6) Rotate disc carrier by 90˚.

Loosen the slotted nut.
※ Special tool
Slotted nut wrench 5870 401 118
Slotted nut wrench 5870 401 115

Figure 67

(7) Rotate disc carrier by 90˚.

Pull off the taper roller bearing.
※ Special tool
Gripping insert 5873 011 012
Basic tool 5873 001 000

Figure 68

(8) Pull off the spur gear K4 from the disc

carrier.
※ Special tool
Three-armed puller 5870 971 003

Figure 69

3-95
(9) Remove the ring.

Figure 70

(10) Pull off the taper roller bearing.

※ Special tool
Three-armed puller 5870 971 002

Figure 71

(11) Squeeze out the snap ring.

Remove the end shim and the disc set
K4.

Figure 72

(12) Preload the compression spring by

means of fixture (S).
Squeeze out the snap ring and the
released single components.
Remove the opposite single components
(K3 side) analogously.
※ Special tool
Pressure piece 5870 345 072

Figure 73

3-96
(13) Separate both pistons by means of
compressed air from the disc carrier.

Figure 74

Dismantling of the multi-disc clutch KR/K2

(1) Fasten the clutch by means of clamping
ring (arrow) on the assembly truck.
※ Special tool
Clamping ring 5870 654 033

Figure 75

(2) Rotate disc carrier by 90˚.

Loosen the slotted nut.
※ Special tool
Slotted nut wrench 5870 401 099

Figure 76

(3) Pull off the taper roller bearing from the

disc carrier.
※ Special tool
Gripping insert 5873 012 018
Basic tool 5873 002 001

Figure 77

3-97
(4) Press off the spur gear K2 from the disc
carrier.
Pay attention to released disc carrier.

Figure 78

(5) Fasten the disc carrier by means of

clamping ring (S).
Pull off the taper roller bearing from the
disc carrier.
※ Special tool
Clamping ring 5870 654 033
Gripping insert 5873 012 019
Basic tool 5873 002 001

Figure 79

(6) Squeeze out the snap ring.

Remove the end shim and disc set K2.

Figure 80

(7) Rotate disc carrier by 90˚.

Loosen the slotted nut.
※ Special tool
Slotted nut wrench 5870 401 099

Figure 81

3-98
(8) Pull off the taper roller bearing from the
disc carrier.
※ Special tool
Gripping insert 5873 002 044
Basic tool 5873 002 001

Figure 82

(9) Fasten spur gear KR by means of

clamping ring (arrow) and pull it from the
disc carrier.
※ Collar of the clamping ring must show
upwards (to the spur gear).
※ Special tool
Three-armed puller 5870 971 003
Clamping ring 5870 654 045
Figure 83

(10) Remove the ring.

Figure 84

(11) Squeeze out the snap ring.

Remove end shim and disc set KR.

Figure 85

3-99
(12) Pull off the taper roller bearing from the
disc carrier.
※ Special tool
Gripping insert 5873 012 013
Basic tool 5873 002 001
Remove both piston (like described in
figure 73 and 74)

Figure 86

Dismantling of the multi-disc clutch KV/K1

(1) Fasten clutch by means of clamping ring
to the assembly truck.
Loosen the slotted nut (figure 87).
※ Special tool
Clamping ring 5870 654 033
Slotted nut wrench 5870 401 118
Slotted nut wrench 5870 401 099

Figure 87

(2) Pull off the taper roller bearing from the

disc carrier.
※ Special tool
Gripping insert 5873 001 023
Basic tool 5873 001 000

Figure 88

(3) Remove the shim.

Figure 89

3-100
(4) Pull off spur gear K1 from the disc carrier.
※ Special tool
Three-armed puller 5870 971 003

Figure 90

(5) Opposite figure shows the spur gear

bearing K1.
Bearing (1) can only be obtained as 1
complete part.
If it is necessary to remove the clutch-
pack-sided ball bearing (arrow or Figure
93 and 94), the complete bearing (1)
has to be removed.

Figure 91

(6) Take off the bush.

Figure 92

(7) Pull off the ball bearing from the disc

carrier (figure 93 and 94).
※ Pay attention to released balls.

Figure 93

3-101
 Figure 94

(8) Squeeze out the snap ring.

Remove end shim and disc set K1.

Figure 95

(9) Rotate disc carrier by 90˚.

Loosen the slotted nut.
※ Special tool
Slotted nut wrench 5870 401 118
Slotted nut wrench 5870 401 115

Figure 96

(10) Pull off the taper roller bearing from the

disc carrier.
※ Special tool
Gripping insert 5873 001 034
Basic tool 5873 001 000

Figure 97

3-102
(11) Pull off spur gear KV from the disc carrier.
※ Special tool
Three-armed puller 5870 971 003

Figure 98

(12) Remove the ring.

Figure 99

(13) Pull off the taper roller bearing from the

disc carrier (figure 100).
Squeeze out the snap ring.
Remove end shim and disc set KV.
Remove both pistons (like described in
Figure 73 and 74).
※ Special tool
Gripping insert 5873 001 034
Basic tool 5873 001 000
Figure 100

3-103
2) ASSEMBLY
2
3rd/4th
3rd/4th power take-off 1

1 = Ball bearing 3
6
2 = Spur gear
3 = Driver
4
4 = Ball bearing
7
5 = Pump flange 5

6 = Cover
7 = Intermediate gear 11 9
8 = Shim
9 = Pin
10 = Sealing cover 10
11 = Orifice 8

Figure 109

(1) Insert the ball bearing (1) into the housing

bore until contact.

Figure 110

(2) Position spur gear (2).

※ Pay attention to the installation position,
see sketch (figure 109).

Figure 111

3-104
(3) Heat the ball bearing (inner ring) and bore
of the gear respectively.

※ (S) Hot-air blower 230V 5870 221 500(S)

Hot-air blower 115V 5870 221 501

Figure 112

(4) Align the spur gear centrally and insert the

driver (3) until con-tact.

※ Pay attention to the installation position,

also see sketch (figure 109).

Figure 113

(5) Install the ball bearing (4) by means of

fixture until contact.
※ Pay attention to perfect contact of the ball
bearing.
Fixture 5870 000 083

Figure 114

Adjust the axial play of power take-off bearing

= 0.2~0.3 mm (figure 115~116)
(6) Fasten ball bearing by means of shim s =
1.80 mm (empirical value) and retaining
ring.
Clamping pliers 5870 900 021

Figure 115

3-105
(7) Check the axial play by means of feeler
gauge.
※ If different from the required axial play =
0.2~0.3 mm this is tobe corrected with the
corresponding shim.
Feeler gauge 5870 200 112

Figure 116

(8) Place the O-Ring (arrow) in the annular

groove of the pumpflange (5) and grease
it.

Figure 117

(9) Fasten the pump flange (5) by means of

hexagon screws.
Tightening torque (M14/8.8) : 12.7 kgf·m
(92.2 lbf·ft)

Figure 118

Converter side
(10) Place the O-Ring (arrow) with assembly
grease in the recess ofthe housing bore.

Figure 119

3-106
(11) Fasten the cover (6) with hexagon screws.
Tightening torque (M14/8.8) : 12.7 kgf·m
(92.2 lbf·ft)
Provide the orifice (arrow) with a new
sealing ring (CU) andinstall it.

Figure 120

(12) Preassemble the intermediate gear (7)

according to figure 121.
※ Exact locating of the single components
to be ensured bypressing

Figure 121

(13) Put in the bearing inner rings and position

the intermediate gear (7), see arrow.

Figure 122

(14) Adjust the axial play-intermediate gear

bearing max. 0.1 mm (figure 123~124)
Determine the gap size by means of
feeler gauge (arrow).
Dim I e.g. ..................................... 1.25 mm
Example
Example
Dim I (gap size) ..........................1.25 mm
Axial play (0~0.1 mm) e.g. ..... - 0.05 mm
resulting shim e.g. s = 1.20 mm Figure 123

Feeler gauge 5870 200 112

3-107
(15) Install the corresponding shim (8) e.g. s =
1.20 mm (arrow).
※ Install shim on the converter side

Figure 124

(16) Align the single components centrically.

Undercool the pin (9) and install it until
contact.

Figure 125

(17) Flush-mount the sealing cover (10) with

1
the concave side showing upwards (arrow
1).
※ Wet contact face of the sealing cover with
loctite (Type No.262).
2
※ Provide orifice (11) with a new O-Ring
and install it (arrow 2).

Figure 126

3-108
 Assembly of the multi-disc clutch K4/K3
The following sketch shows the clutch sectioning

1
3
2
K4 K3

5 4 4 5

Figure 127

1 Disc carrier(assy) K4 Multi-disc clutch K4 5 Compression spring

2 Spur gear K4 K3 Multi-disc clutch K3 6 Plug 2EA
3 Spur gear K3 4 Piston 7 Plug 1EA

※ Observe the installation position of the single components for the following assembly.

3-109
(1) Lift the disc carrier with the K4-side
showing downwards into the clamping
ring (S) and fasten it.
Rotate disc carrier by 180˚.
※ Special tool
Clamping ring 5870 654 033
To install new disc carriers the finished
bores have to be sealed with plugs.
I n s t a l l a t i o n p o s i t i o n , s e e a r r o w,
Figure 128
figure128 and 129.
※ Special tool
Hand inserting tool 5870 320 014
Ratchet spanner 5870 320 018

Figure 129

(2) Flush-mount the drain valve (arrow) with

the chamfer showing downwards.
※ Special tool
Inserting tool 5870 320 019

Figure 130

(3) Put both O-rings scroll-free into the

annular grooves of the piston, see arrows.

Figure 131

3-110
(4) Oil the O-rings and the piston contact
surface.
Install K3 piston equally until contact.
※ Observe the installation position of the
piston, see figure.

Figure 132

(5) Install spacer and compression spring.

Figure 133

(6) Place guide ring, with the chamfer (arrow)

showing upwards, over the compression
spring and install the snap ring.

Figure 134

(7) Lift the disc carrier out of the clamping

ring. Preload the compression spring by
means of fixture (S) and engage the snap
ring into the annular groove of the disc
carrier (arrow), see figure 135.
※ Special tool
Fixture 5870 345 072
Clamping fixture 5870 654 036
Install the drain valve, piston and compr-
ession spring on the opposite side (clutch Figure 135

K4) analogously (figure 130~135).

Then lift the disc carrier with the K4-side
showing downwards into the clamping
ring and fasten it. Rotate disc carrier by
180˚.
3-111
 Disc Components K4
※ Below sketch or table shows the standard version as to the installation position of the single
components. Obligatory is the respective spare parts list.

Figure 136

Position Description Quantity s (mm) Remarks

1 Disc carrier 1
2 Piston 1
3 Outer clutch disc 2 1.85 Coated on one side
4 Outer clutch disc 5 2.5 Coated on both sides
5 Inner clutch disc 3 3.5
6 Inner clutch disc 1 4.0
7 Inner clutch disc 2 2.5~4.0 Optional
8 Snap ring 1 2.10~3.10 Optional
9 End shim 1
Number of friction surfaces : 12
Disc clearance : 2.2 ~ 2.4 mm

※ Install the outer clutch discs position 3 with uncoated side showing to the piston and end shim
respectively. The respective clutch side can be seen on the length of the disc carrier, see sketch.
K4 Dimension X (short disc carrier side)
K3 Dimension Y (long disc carrier side)

3-112
Check disc clearance K4=2.2~2.4 mm
(figure 137~139)
※ In order to ensure a perfect measuring
result, the disc set is first of all to be
installed without oil.
(1) Install disc set according to sketch or
table.

Figure137

(2) Install the end shim and fasten it by

means of the snap ring.

Figure138

(3) Press on end shim with approximately

100N (10 kg) and set dial indicator to
"Zero".
Then press end shim against snap ring
(upwards) and read disc clearance on the
dial indicator.
※ If the required disc clearance differs, it has
to be corrected with the adequate inner
clutch disc or/and snap ring, see table/
position 7 and position 8. Figure139

Upon setting of disc clearance, remove

the disc set, oil the clutch discs and
reinstall them.
※ Special tool
Magnetic stand 5870 200 055
Dial indicator 5870 200 057

3-113
Preassemble and install spur gear K4
(figure 140~144) :
4 1
(1) Opposite figure shows the single 2
components of spur gear K4. 1 2 3
1 Bearing inner ring
2 Bearing outer ring
3 Ring
4 Spur gear
Locate both bearing outer rings (2) until
Figure140
contact.

(2) Heat the bearing inner ring and install it

until contact.

Figure141

(3) Install the ring (3).

Figure142

(4) Assemble the spur gear until all inner

clutch discs are located.

Figure143

3-114
(5) Heat the bearing inner ring (spur gear
bearing) and locate it until contact.
Use safety gloves.

Figure144

(6) Heat the bearing inner ring (clutch

bearing) and install it until contact.
Use safety gloves.

Figure145

3-115
 Clutch Components K3
※ Below sketch or table shows the standard version as to the installation position of the single
components. Obligatory is the respective spare parts list.

Figure146

Position Description Quantity s(mm) Remarks

1 Disc carrier 1
2 Piston 1
3 Outer clutch disc 2 1.85 Coated on one side
4 Outer clutch disc 8 2.5 Coated on both sides
5 Inner clutch disc 7 3.0
6 Inner clutch disc 2 2.5~4.0 Optional
7 Snap ring 1 2.10~3.10 Optional
8 End shim 1
Number of friction surfaces : 18
Disc clearance : 2.6 ~ 2.8 mm

※ Install the outer clutch discs position 3 with uncoated side showing to the piston and end shim
respectively. The respective clutch side can be seen on the length of the disc carrier, see sketch.
K3 Dimension Y (long disc carrier side)
K4 Dimension X (short disc carrier side)

3-116
Check disc clearance K3=2.6~2.8 mm
(figure 147~149)
※ In order to ensure a perfect measuring
result, the disc set is first of all to be
installed without oil.
(1) Install disc set according to sketch or table.

Figure 147

(2) Install the end shim and fasten it by

means of the snap ring.

Figure 148

(3) Press on end shim with approximately

100N (10 kg) and set dial indicator to
"Zero".
Then press end shim against snap ring
(upwards) and read disc clearance on the
dial indicator.
※ If the required disc clearance differs, it has
to be corrected with the adequate inner
clutch disc or/and snap ring, see table/
position 6 and position 7. Figure 149

Upon setting of disc clearance, remove

the disc set, oil the clutch discs and
reinstall them.
※ Special tool
※ Magnetic stand 5870 200 055
Dial indicator 5870 200 057

3-117
(4) Heat the bearing inner ring and install it
until contace.
Use safety gloves.

Figure 150

(5) Lift the disc carrier out of the clamping

ring (S).
To ensure the exact locating of the single
components, preload the bearing with
100KN (10 t) (figure 151)
Support on the lower as well as upper
bearing inner ring.
Use pressure pieces (S).
※ Special tool
Figure 151
Pressure piece 5870 506 096

(6) Lift the disc carrier with the K4-side

showing downwards into the clamping
ring (S) and fasten it.
Rotate disc carrier by 90˚.
Install the slotted nut.
※ Observe installation position of the slotted
nut. Collar (Ø60 mm) must show to the
bearing inner ring, also see sketch (Figure
127). Oil the thread.
Figure 152
·Tightening torque : 56.1 kgf·m (406 lbf·ft)
※ Special tool
Clamping ring 5870 654 033
Slotted nut wrench 5870 401 118
Slotted nut wrench 5870 401 115

3-118
(7) Install the bearing outer ring into spur
gear K3 until contact.

Figure 153

(8) Assemble the spur gear until all inner

clutch discs are located.

Figure 154

(9) Heat the roller bearing and locate it until

contact.
Use safety gloves.

Figure 155

(10) Install the bearing inner ring.

Figure 156

3-119
(11) Check function of the clutches K3 and K4
by means of compressed air.
※ Closing or opening of the clutches is
clearly audible when the single parts have
been installed adequately.

Figure 157

(12) Snap-in and lock the rectangular rings

(3EA, see arrows).

Figure 158

3-120
 Assembly of the multi-disc clutch KR/K2
The following sketch shows the clutch sectioning.

2 1 3

KR K2

5 4 4 5

Figure159

1 Disc carrier K4 Multi-disc clutch KR 5 Compression spring

2 Spur gear KR K2 Multi-disc clutch K2 6 Plug 2EA
3 Spur gear K2 4 Piston 7 Plug 1EA

※ Observe the installation position of the single components for the following assembly.

3-121
(1) Lift the disc carrier with the KR-side
showing downwards into the clamping
ring and fasten it.
Then rotate disc carrier by 180˚.
To install new disc carriers the finished
bores have to be sealed with plugs.
Installation position, see arrow, figure
160~161.
※ Special tool
Figure 160
Clamping ring 5870 654 033
Hand mounting tool 5870 320 014
Ratchet 5870 320 018

Figure 161

(2) Flush-mount the drain valve (arrow) with

the chamfer showing downwards.
※ Special tool
Inserting tool 5870 320 019

Figure 162

(3) Put both O-rings scroll-free into the

annular grooves of the piston, see arrows.

Figure 163

3-122
(4) Oil the O-rings and the piston contact
surface.
Install K2 piston equally until contact.
※ Observe the installation position of the
piston, see figure.

Figure 164

(5) Install spacer and compression spring.

Figure 165

(6) Place guide ring, with the chamfer (arrow)

showing upwards, over the compression
spring and install the snap ring.

Figure 166

(7) Lift the disc carrier out of the clamping

ring. Preload the compression spring by
means of fixture and engage the snap
ring into the annular groove of the disc
carrier (arrow), see figure 167.
Install the drain valve, piston and compr-
ession spring on the opposite side(clutch
K4) analogously (like figure 162~167).
Then lift the disc carrier with the KR-side
showing downwards into the clamping Figure 167
ring and fasten it. Rotate disc carrier by
180˚.
※ Special tool
Pressure piece 5870 345 072
Clamping fixture 5870 654 036

3-123
 Disc Components KR
※ Below sketch or table shows the standard version as to the installation position of the single
components. Obligatory is the respective spare parts list.

Figure 168

Position Description Quantity s (mm) Remarks

1 Disc carrier 1
2 Piston 1
3 Outer clutch disc 2 1.85 Coated on one side
4 Outer clutch disc 11 3.35 Coated on both sides
5 Inner clutch disc 5 2.5
6 Inner clutch disc 5 3.0
7 Inner clutch disc 2 2.5~4.0 Optional
8 Snap ring 1 2.10~3.10 Optional
9 End shim 1
Number of friction surfaces : 24
Disc clearance : 2.8 ~ 3.0 mm

※ Install the outer clutch discs position 3 with uncoated side showing to the piston and end shim
respectively. The respective clutch side can be seen on the length of the disc carrier, see sketch.
KR Dimension X (long disc carrier side)
K2 Dimension Y (short disc carrier side)

3-124
Check disc clearance KR=2.8~3.0 mm
(figure 169~171)
※ In order to ensure a perfect measuring
result, the disc set is first of all to be
installed without oil.
(1) Install disc set according to sketch or table.

Figure 169

(2) Install the end shim and fasten it by

means of the snap ring.

Figure 170

(3) Press on end shim with approximately

100N (10 kg) and set dial indicator to
"Zero".
Then press end shim against snap ring
(upwards) and read disc clearance on the
dial indicator.
※ If the required disc clearance differs, it has
to be corrected with the adequate inner
clutch disc or/and snap ring, see table/
position 7 and Position 8. Figure 171

Upon setting of disc clearance, remove

the disc set, oil the clutch discs and
reinstall them.
※ Special tool
Magnetic stand 5870 200 055
Dial indicator 5870 200 057

3-125
Preassemble and install spur gear KR
(figure 172~176) :
3
(1) Opposite figure shows the single 4
1
components of spur gear KR. 2
1 Bearing inner ring (75×37 mm)
2 Ring
3 Spur gear
4 Bearing inner ring (75×41 mm)

Figure 172

(2) Heat the bearing inner ring (75×37 mm)

and install it until contact.
Use safety gloves.

Figure 173

(3) Assemble the spur gear until all inner

clutch discs are located.

Figure 174

(4) Install the ring.

Figure 175

3-126
(5) Heat the bearing inner ring (75×41 mm)
and locate it until contact.
Use safety gloves.

Figure 176

(6) Heat the bearing inner ring (clutch

bearing) and locate it until contact.
Use safety gloves.

Figure 177

3-127
 Disc Components K2
※ Below sketch or table shows the standard version as to the installation position of the single
components. Obligatory is the respective spare parts list.

Figure 178

Position Description Quantity s (mm) Remarks

1 Disc carrier 1
2 Piston 1
3 Outer clutch disc 2 1.85 Coated on one side
4 Outer clutch disc 8 2.5 Coated on both sides
5 Inner clutch disc 7 3.0
6 Inner clutch disc 2 2.5~4.0 Optional
7 Snap ring 1 2.10~3.10 Optional
8 End shim 1
Number of friction surfaces : 18
Disc clearance : 2.6 ~ 2.8 mm
※ Install the outer clutch discs position 3 with uncoated side showing to the piston and end shim
respectively. The respective clutch side can be seen on the length of the disc carrier, see sketch.
K2 Dimension X (short disc carrier side)
KR Dimension Y (long disc carrier side)

3-128
Check disc clearance K2=2.6~2.8 mm
(figure 179~181)
※ In order to ensure a perfect measuring
result, the disc set is first of all to be
installed without oil.
(1) Install disc set according to sketch or table.

Figure 179

(2) Install the end shim and fasten it by

means of the snap ring.

Figure 180

(3) Press on end shim with approximately

100N (10 kg) and set dial indicator to
"Zero".
Then press end shim against snap ring
(upwards) and read disc clearance on the
dial indicator.
※ If the required disc clearance differs, it has
to be corrected with the adequate inner
clutch disc or/and snap ring, see table/
position 6 and position 7. Figure 181

Upon setting of disc clearance, remove

the disc set, oil the clutch discs and
reinstall them.
※ Special tool
Magnetic stand 5870 200 055
Dial indicator 5870 200 057

3-129
Preassemble and install spur gear K2
(figure182~186) :
(1) Undercool gear 1 (approx -80˚C) and heat
1 2
gear 2 (approx 120˚C).
Engage the snap ring(arrow), preload it
and join both components by means of
hydraulic press until the snap ring engag-
es into the annular groove of gear 2.

Figure 182

(2) Opposite figure shows the single

components of the spur gear bearing.
1 Bearing inner ring
2 Spur gear assy
3 Bearing inner ring 1

3
2
Figure 183

(3) Heat the bearing inner ring and install it

until contact.
Use safety gloves.

Figure 184

(4) Assemble the spur gear until all inner

clutch discs are located.

Figure 185

3-130
(5) Heat the bearing inner ring (spur gear
bearing) and install it until contact.
Use safety gloves.

Figure 186

(6) Heat the bearing inner ring (clutch

bearing) and locate it until contact.
Use safety gloves.

Figure 187

(7) Lift the disc carrier out of the clamping

ring.
To ensure the exact locating of the single
components, preload the bearing with 100
KN (10t) (figure 188)
Support on the lower as well as upper
bearing inner ring.
Use pressure pieces (S).
※ Special tool
Figure 188
Pressure piece 5870 506 096

3-131
(8) Lift the disc carrier into the clamping ring
and fasten it.
Rotate disc carrier by 90˚.
K2-side :
Install the slotted nut.
※ Observe installation position of the slotted
nut. Chamfer must show to the bearing
inner ring, also see sketch (Figure 159).
Oil the thread.
Figure 189
·Torque limit : 56.1 kgf·m (406 lbf·ft)
※ Special tool
Clamping ring 5870 654 033
Slotted nut wrench 5870 401 099

KR-side :
Install the slotted nut.
※ Observe installation position of the slotted
nut. Collar (Ø76 mm) must show to the
bearing inner ring, also see sketch/page
3-113. Oil the thread.
·Torque limit : 56.1 kgf·m (406 lbf·ft)
※ Special tool
Slotted nut wrench 5870 401 099 Figure 190

(9) Check function of the clutches K3 and K4

by means of compressed air (figure 191).
※ Closing or opening of the clutches is
clearly audible when the single parts have
been installed adequately.
Snap-in and lock the rectangular rings
(3EA, see arrows).

Figure 191

3-132
 Assembly of the multi-disc clutch KV/K2
The following sketch shows the clutch sectioning

2 1

KV K1
7

5 4 4 5
Figure 192

1 Disc carrier KV Multi-disc clutch KV 5 Compression spring

2 Spur gear KV K1 Multi-disc clutch K1 6 Plug 2EA
3 Spur gear K1 4 Piston 7 Plug 1EA

※ Observe the installation position of the single components for the following assembly.

3-133
(1) Lift the disc carrier with the KV-side
showing downwards into the clamping
ring(S) and fasten it.
Then rotate disc carrier by 180˚.
To install new disc carriers the finished
bores have to be sealed with plugs.
I n s t a l l a t i o n p o s i t i o n , s e e a r r o w,
figure193~194.
※ Special tool
Figure 193
Hand mounting tool 5870 320 014
Ratchet spanner 5870 320 018

Figure 194

(2) Flush-mount the drain valve (arrow) with

the chamfer showing downwards.
※ Special tool
Inserting tool 5870 320 019

Figure 195

(3) Put both O-rings scroll-free into the

annular grooves of the piston, see arrows.

Figure 196

3-134
(4) Oil the O-rings and the piston contact
surface.
Install K1 piston equally until contact.
※ Observe the installation position of the
piston, see figure.

Figure 197

(5) Install spacer and compression spring.

Figure 198

(6) Place guide ring, with the chamfer (arrow)

showing upwards, over the compression
spring and install the snap ring.

Figure 199

(7) Lift the disc carrier out of the clamping

ring. Preload the compression spring by
means of fixture and engage the snap
ring into the annular groove of the disc
carrier (arrow), see figure 200.
Install the drain valve, piston and compr-
ession spring on the opposite side (clutch
KV) analogously.
Then lift the disc carrier with the KV-side
showing downwards into the clamping Figure 200
ring and fasten it.
Rotate disc carrier by 180˚.
※ Special tool
Pressure piece 5870 345 072
Clamping fixture 5870 654 036

3-135
 Disc Components KV
※ Below sketch or table shows the standard version as to the installation position of the single
components. Obligatory is the respective spare parts list.

Figure 201

Position Description Quantity s (mm) Remarks

1 Disc carrier 1
2 Piston 1
3 Outer clutch disc 2 1.85 Coated on one side
4 Outer clutch disc 11 2.5 Coated on both sides
5 Inner clutch disc 9 3.5
6 Inner clutch disc 1 4.0
7 Inner clutch disc 2 2.5~4.0 Optional
8 Snap ring 1 2.10~3.10 Optional
9 End shim 1
Number of friction surfaces : 24
Disc clearance : 2.8 ~ 3.0 mm

※ Install the outer clutch discs position 3 with uncoated side showing to the piston and end shim
respectively. The respective clutch side can be seen on the length and Ø of the disc carrier resp-
ectively, see sketch.
KV Dimension Y (long disc carrier side and large Ørespectively)
K1 Dimension X (short disc carrier side and small Ørespectively)

3-136
Check disc clearance KV=2.8~3.0 mm
(figure 202~204)
※ In order to ensure a perfect measuring
result, the disc set is first of all to be
installed without oil.
(1) Install disc set according to sketch or table.

Figure 202

(2) Install the end shim and fasten it by

means of the snap ring.

Figure 203

(3) Press on end shim with approximately

100N (10 kg) and set dial indicator to
"Zero".
Then press end shim against snap ring
(upwards) and read disc clearance on the
dial indicator.
※ If the required disc clearance differs, it has
to be corrected with the adequate inner
clutch disc or/and snap ring, see table/
position 7 and position 8. Figure 204

Upon setting of disc clearance, remove

the disc set, oil the clutch discs and
reinstall them.
※ Special tool
Magnetic stand 5870 200 055
Dial indicator 5870 200 057

3-137
Preassemble and install spur gear KV
(figure 205~209) :
(1) Opposite figure shows the single
components of spur gear KV.
1 Bearing inner ring
2 Bearing outer ring
2 1
3 Ring
3 4
4 Spur gear 1 2

Install both bearing outer rings (2) until Figure 205

contact.

(2) Heat the bearing inner ring and install it

until contact.
Use safety gloves.

Figure 206

(3) Install the ring.

Figure 207

(4) Assemble the spur gear until all inner

clutch discs are located.

Figure 208

3-138
(5) Heat the bearing inner ring (spur gear
bearing) and locate it until contact.
Use safety gloves.

Figure 209

(6) Heat the bearing inner ring (clutch

bearing) and locate it until contact.
Use safety gloves.
Rotate disc carrier by 180˚.

Figure 210

3-139
 Disc Components K1
※ Below sketch or table shows the standard version as to the installation position of the single
components. Obligatory is the respective spare parts list.

Figure 211

Position Description Quantity s (mm) Remarks

1 Disc carrier 1
2 Piston 1
3 Outer clutch disc 2 1.85 Coated on one side
4 Outer clutch disc 8 2.5 Coated on both sides
5 Inner clutch disc 7 2.5
6 Inner clutch disc 2 2.5~4.0 Optional
7 Snap ring 1 2.1~2.5 Optional
8 End shim 1
Number of friction surfaces : 18
Disc clearance : 2.6 ~ 2.8 mm

※ Install the outer clutch discs position 3 with uncoated side showing to the piston and end shim
respectively. The respective clutch side can be seen on the length andØof the disc carrier resp-
ectively, see sketch.
K1 Dimension X (short disc carrier side and small Ørespectively)
KV Dimension Y (long disc carrier side and large Ørespectively)

3-140
Check disc clearance KV=2.6~2.8 mm
(figure 212~214)
※ In order to ensure a perfect measuring
result, the disc set is first of all to be
installed without oil.
(1) Install disc set according to sketch or table.

Figure 212

(2) Install the end shim and fasten it by

means of the snap ring.

Figure 213

(3) Press on end shim with approximately

100N (10 kg) and set dial indicator to
"Zero".
Then press end shim against snap ring
(upwards) and read disc clearance on the
dial indicator.
※ If the required disc clearance differs, it has
to be corrected with the adequate inner
clutch disc or/and snap ring, see table/
position 6 and position 7. Figure 214

Upon setting of disc clearance, remove

the disc set, oil the clutch discs and
reinstall them.
※ Special tool
Magnetic stand 5870 200 055
Dial indicator 5870 200 057

3-141
Preassemble and install spur gear K1
(figure 215~222) :
1
(1) Opposite figure shows the single
components of spur gear K1.
1 Ball bearing (assy)
2 Snap ring
3 Spur gear 3
2
※ Prior to installation of the single com-
ponents, align the disc set by means of Figure 215

the spur gear radially and center it, see

figure 216.

Figure 216

(2) Install the ring.

Figure 217

(3) Install the bush with collar (arrow) on face

end showing to the snap ring.

Figure 218

3-142
(4) Press in the ball bearing until contact.
※ Install the ball bearing with the lubricating
groove (arrow) showing downwards.
Put the press-in tool only to te bearing
outer ring.

Figure 219

(5) Heat the second ball bearing and install it

until contact.
※ Lubricating groove (arrow), must show
upwards.
Use safety gloves.

Figure 220

(6) Assemble the bush.

Figure 221

(7) Heat the spur gear to approximately

120˚C and assemble it until all inner
clutch discs are located.
Use safety gloves.

Figure 222

3-143
(8) Install shim s = 1.20 mm

Figure 223

(9) Heat the bearing inner ring and install it

until contact.
Use safety gloves.

Figure 224

(10) Lift the disc carrier out of the clamping

ring (S). To ensure the exact locating of
the single components, preload the
bearing with 100KN (10 t) (figure 225).
Support on the lower as well as upper
bearing inner ring.
Use pressure pieces (S).
※ Special tool
Pressure pieces 5870 506 096
Figure 225

3-144
(11) Lift the disc carrier into the clamping ring
(S). Rotate disc carrier by 90˚.
Install the slotted nut.
※ Observe installation position of the slotted
nut. Collar (Ø60 mm) must show to the
taper roller bearing also see sketch
(Figure 192). Oil the thread.
·Torque limit : 56.1 kgf·m (406 lbf·ft)
※ Special tool Figure 226

Slotted nut wrench 5870 401 118

Slotted nut wrench 5870 401 099
Install the opposite slotted nut (KV-side)
analogously.
※ Special tool
Slotted nut wrench 5870 401 118
Slotted nut wrench 5870 401 115

(12) Check function of the clutches KV and K1

by means of compressed air.
※ Closing or opening of the clutches is
clearly audible when the single parts have
been installed adequately.

Figure 227

(13) Snap-in and lock the rectangular rings

(3EA, see arrows).

Figure 228

3-145
Installation of layshaft gear, multi-disc
clutches and output gear 3
1
(1) Opposite figure shows the single compon- 1 2
ents of the layshaft gear bearing.
1 Bearing inner ring (2EA)
2 Ring
3 Layshaft gear

Figure 229

(2) Position layshaft gear (assy) in the

housing.
※ Only when the clutches are installed, the
idler shaft can be mounted.

Figure 230

(3) Insert the bearing outer rings KV/K1, KR/

K2 and K3/K4 into the housing bores until
contact, see arrows.

Figure 231

(4) Position clutch KV/K1 by means of lifting

tackle.
※ Special tool
Eyebolts assortment 5870 204 002

Figure 232

3-146
(5) Position clutch KR/K2.
※ Special tool
Eyebolts assortment 5870 204 002

Figure 233

(6) Check the installation position of the

layshaft gear (arrow) once again and
correct it, if required.

Figure 234

(7) Fasten the spur gear K3 by means of

fixture and eyebolt (arrow) axially.
※ Spur gear fixing prevents the clutch discs
from dislocating when the clutch is lifted
in.
※ Special tool
Assembly fixture 5870 345 033
Eyebolt 5870 204 066
Figure 235

(8) Lift the clutch KR/K2 slightly, move it in

direction of the arrow and position clutch
K3/K4.
Then remove the fixture (figure 235) again.

Figure 236

3-147
(9) Insert the bearing outer ring into the
housing bore until contact.

Figure 237

(10) Heat the bearing inner ring and install it

until contact.
Use safety gloves.
※ Observe installation position-collar (arrow)
shows to the spur gear. Install the bearing
inner ring after cooling down subsequently
(press).

Figure 238

(11) Position the oil baffle.

Figure 239

(12) Install the output gear by means of lifting

tackle.
※ Special tool
Stop washer 5870 100 054
Eyebolts assortment 5870 204 002

Figure 240

3-148
(13) Position upper oil baffle and fasten both
plates by means of hexagon screws (4EA).
※ Install washers.
Secure hexagon screws with loctite (type
No.243).
·Torque limit : 2.35 kgf·m (16.7 lbf·ft)

Figure 241

Preassembly and mounting of the housing

cover
Note to figure 242 and 243 :
Depending on the transmission version,
differences as regards the single compon-
ents and their installation position are
possible.
Obligatory is the respective parts list.
(1) Install the sealing cover (arrow).
Figure 242
※ Wet the sealing surface with Loctite (type
No.262).

(2) Insert the O-ring into the annular groove

of the cover and fasten the cover by
means of hexagon screws.
※ Wet the thread of the hexagon screws
with loctite (type No.574). Observe the
installation position of the cover, see
figure.
·Torque limit : 2.35 kgf·m (16.7 lbf·ft)

Figure 243

(3) Wet the mounting face with sealing

compound (loctite, type No.574).
By means of the lifting tackle place the
housing cover on the transmission
housing until contact.
※ Special tool
Lifting tackle 5870 281 055

Figure 244

3-149
(4) Install both cylindrical pins (arrow 1 and 2)
and the slotted pin (arrow 3). 2
Then fasten the housing cover by means
of hexagon and cap screws.
·Torque limit M10/8.8 :
4.69 kgf·m (33.9 lbf·ft)
3 1

Figure 245

Adjust the bearing preload of clutch K4/K3

= 0.0~0.05 mm (figure 248~250)
※ For installation of a new bearing cover,
both finished bores have to be sealed by
means of a plug.
Finished bores are located opposite
(180˚) to each other, also see arrow/figure
246 and 247.
1 Bearing cover-K4/K3
Figure 246
2 Plug (konig)
(S) Special tool
※ Special tool
Hand mounting tool 5870 320 014
Ratchet spanner 5870 320 018

Figure 247

3-150
Housing dimension :
(1) Press on equally the bearing inner ring
and detemine Dimension I, from the
mounting face to the bearing inner ring.
Dimension I e.g ----------------------- 43.65 mm
※ Take several measuring points and
determine the mean value.
Then remove the bearing inner ring again.
※ Special tool Figure 248

Measuring shaft 5870 200 022

Digital depth gauge 5870 200 072

Cover dimension :
(2) Determine Dimension II, from the mount-
ing face until contact/bearing inner ring.
Dimension II e.g ------------------------ 42.12 mm
※ Special tool
Straightedge 5870 200 022
Gauge blocks 5870 200 067
Digital depth gauge 5870 200 072
Figure 249

Example :
Dimension I ----------------------------- 43.65 mm
Dimension II ---------------------------- - 42.12 mm
Difference ------------------------------- = 1.53 mm
Bearing preload --------------- e.g. + 0.02 mm
Resulting shim(s) ------------- s = 1.55 mm
(3) Put on the shim.

Figure 250

(4) Heat the bearing inner ring and place it

until contact.
Use safety gloves.
※ Install the bearing inner ring after cooling
down subsequently (press).

Figure 251

3-151
(5) Grease the rectangular rings (3EA,
arrows) and centrally align them.

Figure 252

(6) Install the O-ring (arrow) and grease it.

Heat the inner diameter of the bearing
cover (bearing seat).
※ Special tool
Hot-air blower 230V 5870 221 500
Hot-air blower 115V 5870 221 501

Figure 253

(7) Install two adjusting screws.

Assemble the bearing cover and tighten it
equally until contact by means of hexagon
screws.
·Torque limit (M10/8.8) :
4.69 kgf·m (33.9 lbf·ft)
※ Observe the radial installation position.
※ Special tool
Adjusting screws 5870 204 007 Figure 254

(8) Check the function of both clutches by

means of compressed air.
※ In case of a decisive pressure loss, the
possible cause might be the breakage of
one or several rectangular rings (see
arrow , figure 252).
Replace the rectangular rings, if required.

Figure 255

3-152
Adjust the bearing preload of clutch KR/K2
= 0.0~0.05 mm (figure 258~262)
※ For installation of a new bearing cover, 1
both finished bores have to be sealed by
means of a plug. 2
Finished bores are located opposite (18˚)
to each other, also see arrow/Figure 256 (S)
and 257.
1 Bearing cover-KR/K2
Figure 256
2 Plug
(S) Special tool
※ Special tool
Hand mounting tool 5870 320 014 1
Ratchet spanner 5870 320 018
2

(S)

Figure 257

(1) Install both studs (arrows).

※ Wet the thread with loctite (type No. 243).
·Torque limit (M10) :
1.33 kgf·m (9.59 lbf·ft)

Figure 258

(2) Install the bearing outer ring until contact.

※ Pay attention to exact contact.

Figure 259

3-153
Housing dimension :
(3) Determine Dimension I, from the bearing
outer ring to the mounting face.
Dimension I e.g ------------------------- 16.13 mm

Figure 260

Cover dimension :
(4) Determine Dimension II, from the contact/
bearing outer ring to the mounting face.
Dimension II e.g ------------------------ 17.75 mm
※ Special tool
Digital depth gauge 5870 200 072

Figure 261

Example :
Dimension II ---------------------------- 17.75 mm
Dimension I ---------------------------- - 16.13 mm
Difference ------------------------------- = 1.62 mm
Bearing preload --------------- e.g. + 0.03 mm
Resulting shim (s) ------------- s = 1.65 mm
(5) Fix the shim with assembly grease into
the cover. Install the O-ring (arrow).
Figure 262

(6) Grease the rectangular rings (arrows) and

centrally align them.

Figure 263

3-154
(7) Pull the bearing cover equally until
contact.
·Torque limit (M10/8.8) :
4.69 kgf·m (33.9 lbf·ft)

Figure 264

(8) Check the function of both clutches by

means of compressed air.
※ In case of a decisive pressure loss, the
possible cause might be the breakage of
one or several rectangular rings (see fig-
ure 263).
Replace the rectangular rings, if required.

Figure 265

3-155
Adjust the bearing preload of clutch KV/K1
= 0.0~0.05 mm (figure 267~270) 1
※ For installation of a new bearing cover,
both finished bores have to be sealed by
means of a plug.
Installation position, see arrows/Figure 2
266.
(S)
1 Bearing cover-KV/K1
2 Plug
Figure 266
(S) Special tool
※ Special tool
Hand mounting tool 5870 320 014
Ratchet spanner 5870 320 018

(1) Put the bearing outer ring over the

bearing inner ring.
Housing dimension :
Press on equally the bearing outer ring
and determine Dimension I, from the
mounting face to the bearing outer ring.
Dimension I e.g -------------------------- 52.67 mm
※ Take several measuring points and
determine the mean value. Figure 267

(2) Put the ring with the chamfer showing

downwards into the bearing cover.

Figure 268

3-156
Cover dimension :
(3) Determine Dimension II, from the mount-
ing face to the ring.
Dimension II e.g ------------------------ 50.75 mm
※ Special tool
Digital depth gauge 5870 200 072
Gauge blocks 5870 200 067

Figure 269

Example :
Dimension I ----------------------------- 52.67 mm
Dimension II --------------------------- - 50.75 mm
Difference --------------------------- e.g. 1.92 mm
Bearing preload ---------------------- + 0.03 mm
Resulting shim (s) ------------- s = 1.95 mm
(4) Put in the shim.

Figure 270

(5) Install the bearing outer ring until contact.

Assemble the O-ring (arrow).

Figure 271

(6) Grease the rectangular rings (arrows) and

centrally align them.

Figure 272

3-157
(7) Heat the bearing bore.
※ Special tool
Hot-air blower 230V 5870 221 500
Hot-air blower 115V 5870 221 501

Figure 273

(8) Install two adjusting screws.

Place the bearing cover until contact and
fasten it by means of hexagon screws.
※ Observe the radial installation position,
see figure.
※ Special tool
Adjusting screws 5870 204 007

Figure 274

(9) Check the function of both clutches by

means of compressed air.
※ In case of a decisive pressure loss, the
possible cause might be the breakage of
one or several rectangular rings (see
arrow, figure 272).
Replace the rectangular ring (s), if
required.

Figure 275

3-158
Output
Installation of the output shaft
(1) Heat the inner diameter of the output gear.
※ Special tool
Hot-air blower 230V 5870 221 500
Hot-air blower 115V 5870 221 501

Figure 276

(2) Assemble the output shaft with the long

gearing showing downwards until contact.

Figure 277

(3) Rotate the transmission housing into the

vertical position (90˚).
By means of the mounting tool the output
shaft has preliminarily to be fixed axially
(figure 278 and 279) at the convert-er
side.
※ Special tool
Mounting tool 5870 048 265
Then rotate the transmission housing
Figure 278
back again (90˚).

Figure 279

3-159
Adjust the axial play of the output bearing
= 0.3~0.5 mm (figure 280~282)
(4) Determine Dimension I, from plane face/
housing to end face/output shaft.
Dimension I e.g ------------------------- 66.90 mm
※ Special tool
Digital depth gauge 5870 200 072

Figure 280

(5) Measure Dimension II, from plane face/

housing to contact face/ball bearing.
Dimension II e.g ------------------------ 64.20 mm
Example :
Dimension I ------------------------------ 66.90 mm
Dimension II --------------------------- - 64.20 mm
Difference ------------------------------- = 2.70mm
Required axial play ---------- e.g. - 0.40 mm
(0.3~0.5 mm)
Figure 281
Resulting shim ------------- s = 2.30 mm

(6) Install the shim.

Figure 282

(7) Install the ball bearing (figure 283) and

pull it until contact by means of the output
flange (figure 284).
Then remove the output flange again.

Figure 283

3-160
 Figure 284

(8) Fasten the ball bearing by means of

retaining ring.
※ Clamping pliers 5870 900 021

Figure 285

(9) Remove the converter-side mounting tool

again.
Install the shaft seal, (arrow) with the
sealing lip showing to the oil sump.
※ Using of the specified mounting tool (S),
results in the exact installation position
(without retaining ring = 20 mm).
Grease the sealing lip.
※ Special tool
Figure 286
Mounting tool 5870 048 265
※ Depending on the version different shaft
seals can be used :
Outer diameter rubber-coated-wet it with
spirit. Outer diameter metallic-wet it with
sealing compound (loctite, type No. 574).

3-161
Adjust gap size X = 0.3~0.8 mm
2
(figure 289~292) :

X Gap size
1 Shim
1
2 O-ring.

Figure 289

(1) Install the output flange until contact.

Measure Dimension I, from the plane face
of the output flange to the end face of the
output shaft.
Dimension I e.g --------------------------37.00 mm
※ Special tool
Digital depth gauge 5870 200 072

Figure 290

(2) Measure Dimension II, from the plane

face to the collar of the output flange.
Dimension II e.g. ---------------------- 36.00 mm
Example :
Dimension I ------------------------------ 37.00 mm
Dimension II --------------------------- - 36.00 mm
Difference ------------------------------- = 1.00 mm
Gap size X ----------------------- e.g. - 0.50 mm
(0.3~0.8 mm)
Figure 291
Resulting shim ------------------ s = 0.50 mm

3-162
(3) Place the O-ring (arrow) into the space
between output flange and shaft (see also
figure 289) and put on the shim.

Figure 292

(4) Put on the washer and fasten the output

flange by means of hexagon screws.
·Torque limit (M10/8.8) :
4.69 kgf·m (33.9 lbf·ft)

Figure 293

(5) Fasten the hexagon screws by means of

the lock plate.
※ Specail tool
Mounting tool 5870 057 009
Handle 5870 260 002

Figure 294

3-163
Output flange - parking brake
(1) Press on the screen sheet (arrow) until
contact.
※ The installation position of the screen
sheet is identical with the output flange.
Pressing bush 5870 506 138

Figure 295

(2) Install the output flange-brake disk until

contact.

Figure 296

Mount the brake (figure 297~301)

For working on the brake system, the
instructions and specifications of the
brake manufacturer are mandatory.
(3) Remove the screw cap and loosen the
locking nut (wrench size 30).
Unscrew the adjusting screw in
>13
counterclockwise direction until a
demension > 13.0 mm (brake disc shim)
Figure 297
results (figure 297).

(4) Position the brake and fasten it with cap

screws.
Tightening torque M14/8.8) : 12.7 kgf·m
(92.2 lbf·ft)
Socket spanner 5870 656 047

Figure 298

3-164
Adjust the nominal clearance = 2.0 mm (figure
299~301)
(5) Make the pressure connection and apply
the required release pressure = 150 bar to
the brake (cup spring set preloaded).
Fasten the adjusting screw in clockwise
direction until both brake lining carriers
contact the brake disc (turning of the
adjusting screw is then not possible or
admissible any more without a higher Figure 299

application of force).
Then turn back the adjusting screw by 4/5
turns in counterclockwise direction. 4/5
turns is equal to a nominal clearance of
2.0 mm.

(6) Keep the adjusting screw positioned and

fix it by means of a lock nut.
HP-Pump 5870 287 007
Mini-measuring hub 5870 950 102

Figure 300

(7) Put new O-Ring into the screw cap and

grease it.
Install the screw cap.

Figure 301

3-165
Output Flange (converter side)
(1) Install the shaft seal (arrow) with the
sealing lip showing to the oil sump.
※ Using of the specified mounting tool,
results in the exact installation position
(with retaining ring = 7.0 mm).
Grease the sealing lip.
※ Special tool
Mounting tool 5870 048 265 Figure 302

※ Depending on the version different shaft

seals can be used :
Outer diameter rubber-coated-wet it with
spirit. Outer diameter metallic-wet it with
sealing compound (loctite, Type No. 574).

(1) Press the screen sheet (arrow) over the

collar of the output flange until contact.
※ Observe the installation position, see
figure 304.
※ Special tool
Pressing bush 5870 506 138

Figure 303

1 Screen sheet
2 Output flange
1

Figure 304

3-166
(2) Install the output flange until contact.
※ Setting of the gap size as well as fixing of
the output flange is identical with the
installation of the output flange at the
transmission rearside, see page 3-155
and 3-156.

Figure 305

Installation of the idler shaft

(1) Align the layshaft gear and the single
components centrically.
Heat the layshaft gearing (figure 306).
※ Special tool
Hot-air blower 230V 5870 221 500
Hot-air blower 115V 5870 221 501

Figure 306

(2) Install the adjusting screw.

※ Special tool
Adjusting screws 5870 204 007

Figure 307

(3) Install the idler shaft until contact.

Figure 308

3-167
(4) Remove the adjusting screw and fasten
the axle by means of hexagon screw.
※ Wet the thread of the hexagon screw with
Loctite (type No. 243).
·Torque limit (M10/8.8) :
4.69 kgf·m (33.9 lbf·ft)

Figure 309

(5) Insert the sealing covers (arrow), with the

concave side showing downwards, flush
to the housing surface.
※ Wet contact face with Loctite (type No.
262).

Figure 310

Transmission pump
(with 2nd/3rd or 4th power take-off)
(1) Press the needle sleeve (arrow), with the
reinforced coating towards the press-in
tool until contact.
Mounting tool 5870 058 041
Handle 5870 260 002

Figure 311

(2) Locate the bearing outer ring until contact.

Figure 312

3-168
(3) Install the O-Ring (arrow) and grease it.

Figure 313

(4) Heat the housing bore.

Preheating bush 5870 801 006
Hot-air blower 230 V 5870 221 500
Hot-air blower 115 V 5870 221 501

Figure 314

(5) Install two adjusting screws and assemble

the pump until contact.
※ Observe the radial installation position.
Adjusting screws 5870 204 021

Figure 315

(6) Put the O-Ring (arrow) into the annular

groove of the pump flange.
※ Depending on the transmission version,
differences as regards the version and
fastening of the pump flange are possible.
Obligatory is the respective parts list.

Figure 316

3-169
(7) Fasten the pump flange and pump
respectively by means of cap screws.
※ Wet thread of both cap screws (position,
see arrows) with loctite, Type No. 574
(through holes).
※ Tightening torque (M12/8.8) : 8.06 kgf·m
(58.3 lbf·ft)

Figure 317

(8) Rotate the transmission housing by 180˚.

Snap the V-rings (3X) into the recess of
the driver (internal gearing).
Install the key (arrow).

Figure 318

(9) Install shim s = 2.0 mm and locate the

bearing inner ring until contact.

Figure 319

(10) Install shim s = 2.0 mm.

Figure 320

3-170
(11) Install the driver by means of clamping
plate until contact and fasten it by means
of cap screw.
※ Tightening torque M10/8.8, DIN 6912) :
3.26 kgf·m (23.6 lbf·ft)
※ Wet thread of the cap screw with loctite
(Type No. 243).

Figure 321

(12) Press the bearing inner ring until contact.

Figure 322

(13) Snap in the retaining ring (arrow) and

install the input gear.
Set of external pliers 5870 900 015

Figure 323

(14) Snap-in and lock the rectangular ring

(arrow).

Figure 324

3-171
(15) Install the preassembled input shaft until
contact.
※ Pay attention to align the key to the
keyway.

Figure 325

Adjust the axial play of the input shaft bearing

= 0.0~0.05 mm (figure 326~328) :
(16) Put on the gasket.
Put on the bearing outer ring, press it on
equally and determine Dim. I, from the
mounting face (gasket) to the bearing
outer ring.
Dim I e.g. .................................. 128.50 mm
※ Take several measuring points and Figure 326

determine the mean value.

(17) Measure Dim II, from the mounting face/

converter bell to the mounting face/
bearing outer ring.
Dim II e.g. ................................ 127.46 mm
Straightedge 5870 200 022
Gauge blocks 5870 200 080
Digital depth gauge 5870 200 072

Figure 327

Example :
Dim I ....................................... 128.50 mm
Dim II ...................................... - 127.46 mm
Difference ............................... = 1.04 mm
Axial play ................................ - 0.04 mm
resulting shim(s) s = 1.00 mm
Put in the shim and locate the bearing
inner ring until contact.

Figure 328

3-172
Transmission pump
(with 1st power take-off)
(1) Press the needle sleeve (arrow), with the
reinforced coating towards the press-in
tool until contact.
※ Special tool
Mounting tool 5870 058 041
Handle 5870 260 002
Figure 329

(2) Snap the V-Rings (3EA) into the recess of

the driver (internal gearing).
Install the key (arrow).

Figure 330

(3) Press the ball bearing over the collar of

the driver until contact.

Figure 331

(4) Install the ball bearing and driver

respectively and press it until contact.
※ Pay attention to align the key to the
keyway.

Figure 332

3-173
(5) Fasten the ball bearing by means of
retaining ring.
※ Special tool
Set of internal pliers 5870 900 013

Figure 333

(6) Install the O-ring (arrow) and grease it.

Figure 334

(7) Heat the housing bore.

※ Special tool
Preheating bush 5870 801 006
Hot-air blower 230V 5870 221 500
Hot-air blower 115V 5870 221 501

Figure 335

(8) Install two adjusting screws and assemble

the pump until contact.
※ Observe the radial installation position.
※ Special tool
Adjusting screws 5870 204 021

Figure 336

3-174
(9) Put the O-ring (arrow) into the annular
groove of the pump flange.
※ Depending on the transmission version,
differences as regards the version and
fastening of the pump flange are possible.
Obligatory is the respective parts list.

Figure 337

(10) Fasten the pump flange and the pump

respectively by means of hexagon screws.
※ Wet thread of both hexagon screws
(position, see arrows) with Loctite, Type
No. 574 (through holes).
·Torque limit (M12/8.8) :
8.06 kgf·m (58.3 lbf·ft)
Then rotate the transmission housing by
90˚. Figure 338

(11) Snap-in and lock the rectangular ring

(arrow).

Figure 339

(12) Install both shims (each 2.0 mm thick)

※ Use assembly grease.

Figure 340

3-175
(13) Heat the bevel bearing inner ring.
※ Special tool
Hot-air blower 230V 5870 221 500
Hot-air blower 115V 5870 221 501

Figure 341

(14) Install the input shaft until contact.

Figure 342

(15) Fasten the input shaft by means of

clamping plate and cap screw (arrow).
·Torque limit (M10/8.8) :
3.26 kgf·m (23.6 lbf·ft)
※ Wet thread of the cap screw with Loctite
(type No. 243).

Figure 343

3-176
Input-Converter Bell
※ To install a new converter bell the finished
bores (3EA) have to be sealed with plugs.
Installation position, see arrow, figure 344.
※ Special tool
Lever riveting tongs 5870 320 016

Figure 344

(1) Locate the bearing outer ring into the

housing bore until contact and install the
bearing inner ring, see arrow.

Figure 345

(2) Install the spur gear (arrow) with the long

collar showing upwards and position it.

Figure 346

(3) Heat the spur gear bore (arrow).

※ Special tool
Hot-air blower 230V 5870 221 500
Hot-air blower 115V 5870 221 501

Figure 347

3-177
(4) Install the input shaft until contact.

Figure 348

(5) Heat the bearing inner ring and install it

until contact.
Use safety gloves.

Figure 349

(6) Install the bearing outer ring until contact.

Figure 350

(7) Snap in the rectangular ring (arrow) into

the annular groove of the input shaft and
lock it.
Then grease the rectangular ring and
centrally align it.

Figure 351

3-178
(8) Install the converter safety valve (arrow 1)
and fasten it by means of slotted pin
(arrow 2).
※ Flush-mount slotted pin to recess.
1
Put the O-ring (arrow 3) into the annular
groove.

3 2
Figure 352

(9) Press the needle bearing (arrow), with the

reinforced coating towards the press-in
tool into the bore of the bearing cover until
contact.
※ Special tool
Mounting tool 5870 058 051
Handle 5870 260 002

Figure 353

(10) Flush-mount the shaft seal (arrow) with

the sealing lip showing (downwards) to
the oil sump.
※ Wet the outer diameter with spirit.
Grease the sealing lip.
※ Special tool
Mounting tool 5870 048 030

Figure 354

※ Make the following steps (figure 355~358)

in direct time sequence to secure the
precise contact of the oil supply flange.
(11) Heat the housing bore.
※ Special tool
Preheating bush 5870 801 006
Hot-air blower 5870 221 500
Hot-air blower 5870 221 501
Figure 355

3-179
(12) Install two adjusting screws and put in the
oil supply flange until contact.
※ Observe the radial installation position.
※ Special tool
Adjusting screws 5870 204 007

Figure 356

(13) Place the O-ring (arrow) with assembly

grease into the annular groove of the
bearing cover.

Figure 357

(14) Put on the bearing cover and fasten it by

means of hexagon screws.
·Torque limit (M10/8.8) :
4.69 kgf·m (33.9 lbf·ft)

Figure 358

(15) Install the single components according to

the opposite figure.
1 Screw plug : 15.3 kgf·m (110 lbf·ft)
2 Screw plug : 2.55 kgf·m (18.4 lbf·ft) 2
3 Temperature sensor :
2.55 kgf·m (18.4 lbf·ft)
and screw plug respectively(depending
on the version) : 3.57 kgf·m (25.8 lbf·ft) 1 3

※ Always install new O-ring.

Figure 359

3-180
Converter pressure back-up valve
(figure 360~361)
(1) Install the slotted pin (6×50 mm) until
contact.

Figure 360

(2) Assemble piston and compression spring.

Provide screw plug with a new O-ring and
install it.
·Torque limit (M36×1.5) :
13.3 kgf·m (95.9 lbf·ft)

Figure 361

(3) Fasten the gasket and cover plate by

means of hexagon screws (install the
washers).
·Torque limit (M6/8.8) :
0.97 kgf·m (7.0 lbf·ft)

Figure 362

(4) Install two adjusting screws and put on

the gasket (arrow 1). Put the O-ring
(arrow 2) into the annular groove.
※ Special tool 1
Adjusting screws 5870 204 021

Figure 363

3-181
(5) Install the converter bell by means of
lifting tackle until contact.
※ Slight rotary motions of the input shaft
facilitate the installation (protect teeth from
damage). Observe the radial installation
position.
※ Special tool
Lifting tackle 5870 281 047
Eyebolts assortment 5870 204 002
Figure 364

(6) Fasten the converter bell by means of

hexagon screws.
·Torque limit (M8/10.9) :
3.47 kgf·m (25.1 lbf·ft)
·Torque limit (M12/10.9) :
11.7 kgf·m (84.8 lbf·ft)

Figure 365

(7) Fasten flexible plate (3EA) by means of

hexagon screws (install the washers).
※ Wet thread of the hexagon screws with
Loctite (type No. 243).
·Torque limit (M10/8.8) :
4.69 kgf·m (33.9 lbf·ft)

Figure 366

(8) Install the rectangular ring (arrow) into the

annular groove and lock it.
Then grease the rectangular ring and
centrally align it.

Figure 367

3-182
(9) Assemble converter by means of lifting
tackle until contact (figure 368).
※ At a control dimension < 43 mm, the exact
installation position of the converter is
ensured, see Figure 369.
※ Special tool
Eyebolts assortment 5870 204 002
Lifting chain 5870 281 047
Figure 368

Figure 369

Until installation of the transmission, fix

the converter axially, see figure 370.

Figure 370

3-183
Coarse Filter
(1) Install filter (assy) into the housing bore.
※ Oil the sealing (arrow).

Figure 371

(2) Fasten the cover by means of hexagon

screws (install the washers).
※ Install the new O-ring (arrow).
·Torque limit (M8/8.8) :
2.35 kgf·m (17.0 lbf·ft)

Figure 372

Inductive and speed transmitters

(1) Following sketches show the installation
position of the single inductive and speed
transmitters. 9
5
14 Inductive transmitter n-Turbine
9 Inductive transmitter n-Engine 14
5 Inductive transmitter n-Intenal
speed input
13 Speed transmitter n-Output

13

Figure 373

3-184
※ The following figures describe the
installation and setting respectively of the
inductive transmitter n-Engine (9).
Installation of the inductive transmitter
n-Turbine (14) and n-internal speed input

"S"
"A"
I
(5) is to be made analogously.
Observe the different setting dimens-

X
ions "X" :
Inductive transmitter n-Engine (9)
Figure 375
X = 0.5+0.3 mm
Inductive transmitter n-Turbine (14)
X = 0.5+0.3 mm
Induct. transmitter n-int. speed input (5)
X = 0.3
0.3±0.10.1 mm

Adjust Dimension "X" by means of shim

ring (s) (figure 376~381)
(1) Measure Dimension I on the inductive
transmitter, from contact face to screw-in
face.
※ Dimension I e.g -------------------------- 30.00 mm

Figure 376

(2) Turn in the counting disc radially until one

tooth tip is centrally to the inductive
transmitter bore.
Turn the plug gauge until contact.
Locate anvil at the tooth tip and lock it by
means of threaded pin (figure 377 and
378).
※ Special tool
Plug gauge 5870 200 104
Figure 377

※ Special tool
Plug gauge 5870 200 104
II

Figure 378

3-185
(3) Turn out the plug gauge and determine
Dimension II (also see figure 378).
Dimension II e.g ------------------------- 30.10 mm

Figure 379

Example "A1" :
Dimension II 30.10 mm
Dimension X (0.5+0.3 mm) - 0.60 mm
Results in installation dimension A
= 29.50 mm

Example "A2" :
Dimension I 30.00 mm
Installation dimension A - 29.50 mm
Results in shim ring (s) s = 0.50 mm

(4) Install the adequate shim ring (s) and wet

the thread (arrow) with Loctite (type No.
574).

Figure 380

(5) Install the inductive transmitter n-Engine

(9), see arrow.
·Torque limit : 3.06 kgf·m (22.1 lbf·ft)
Set and install the inductive transmitter
n-Turbine (14) and n-internal speed input
(5) analogously.
※ Observe the different setting dimensions.
Installation position of the single inductive
transmitters, also see page 3-171. Figure 381

3-186
Install speed transmitter n-Output/Speedo
X
(13) (figure 382~387)
2
1 Housing 13
2 Spur gear K3 1
3 Disc carrier
13 Speed transmitter (hall sensor) 3
X Setting dimension "X" =1.0+0.5 mm

Figure 382

(1) Opposite figure shows the speed

transmitter (hall sensor).

Figure 383

(2) Determine Dimension I, from the housing

face to spur gear K3.
Dimension I e.g -------------------------- 39.70 mm
※ Special tool
Digital depth gauge 5870 200 072

Figure 384

(3) Measure Dimension II, from the contact

face to the mounting face.
Dimension II e.g ------------------------ 40.00 mm
※ Special tool
Digital depth gauge 5870 200 072

Figure 385

3-187
 Example "B1" :
Dimension I 39.70 mm
Dimension X(1.0 +0.5 mm) - 1.20 mm
Results in installation dimension
= 38.50 mm

Example "B2" :
Dimension II 40.00 mm
Installation dimension A - 38.50 mm
Results in shim(s) s = 1.50 mm Figure 386

(4) Install shims (3EA, s = 0.50 mm) and

grease the O-ring (arrow).

(5) Fasten the speed transmitter by means of

cap screw.
·Torque limit (M8/8.8) :
2.35 kgf·m (17.0 lbf·ft)
※ Installation position of the speed
transmitter, also see figure 373.

Figure 387

3-188
3. AXLE
1) DISASSEMBLY
(1) Disassembly output and brake
① Fix axle to assembly truck.
Assembly truck 5870 350 000
Fixtures 5870 350 077
Clamping brackets 5870 350 075
Support 5870 350 125
7809AX01
※ Before clamping the axle fully turn in the
support.
Position axle first onto the two fixtures,
secure with clamping brackets and then
unbolt the support until contact with the
axle is obtained.

② Loosen screw plugs (3EA, see figure

AX02 and AX03) and drain oil from the
axle.

7809AX02

7809AX03

3-189
③ Remove the breather valve (see arrow).
※ To avoid any damage, the breather valve
must be removed when separating the
output.

7809AX04

④ Secure the output with the lifting device

and loosen hexagon screws.
Then separate the output assy from the
axle housing.
Load carrying device AA00 685 875
※ Fix the load carrying device with wheel
nuts.

7809AX05

⑤ Pull stub shaft and sun gear shaft.

※ Pay attention to potentially releasing
shim(s).

7809AX06

⑥ Fix output to assembly truck.

Assembly truck 5870 350 000
Fixtures (2EA) 5870 350 113

7809AX07

3-190
⑦ Use a lever to remove the cover from the
output shaft.

7809AX08

⑧ Loosen locking screws and remove the

releasing cover.

7809AX09

⑨ Lift the planetary carrier out of the brake

housing by means of the lifting device.
· Rear axle (planetary carrier with 3
planetary gears)
Internal extractor 5870 300 019
Eye bolt 5870 204 073
· Front axle (planetary carrier with 4
planetary gears)
Internal extractor 5870 300 008
7809AX10
Eye nut AA00 680 376

⑩ Pull the tapered roller bearing from the

planetary carrier.
Rapid grip AA00 693 459
Basic tool 5873 004 001
Clamping cylinder 5873 003 016
Pump 5870 287 010

7809AX70

3-191
⑪ Disengage retaining ring.

7809AX71

⑫ Pull off planetary gear.

Extractor AA00 696 012
Clamping cylinder 5873 003 016
Pump 5870 287 010

7809AX72

⑬ Lift the end plate out of the brake

housing.

7809AX73

⑭ Lift the disk package out of the brake

housing.

7809AX12

3-192
⑮ Loosen hexagon screws, remove
releasing disk and cup spring.

7809AX13

16 Mount breather valve and press piston

out of the brake housing by means of
compressed air.

7809AX14

17 If necessary, remove guide ring, back-up

rings and grooved rings out of the
annular grooves of the brake housing
(see arrows).
※ For the installation position of the single
parts please also refer to the following
sketch.

7809AX15

3-193
 Legend to sketch :
1 = Brake housing 1
2 = Guide ring
3 = Back-up ring
4 = Grooved ring
5 = Grooved ring
6 = Back-up ring 2
3
7 = Slide ring seal 4
8 = Output shaft 5
6

7809AX16

18 Lift the brake housing from the output

shaft by means of the lifting device.

7809AX17

19 Use a lever to remove the slide ring seal

from the brake housing.
If necessary, force out both bearing outer
rings.
Resetting device 5870 400 001

7809AX18

3-194
20 Use a lever to remove the slide ring seal
from the output shaft.
Resetting device 5870 400 001

7809AX74

21 Pull the tapered roller bearing from the

output shaft.
Gripping device AA00 633 495
Adapter ring AA00 633 500
Basic tool 5873 004 001
Pressure piece AA00 696 181
Clamping cylinder 5873 003 016
Pump 5870 287 010

7809AX75

3-195
(2) Disassembly axle housing
① Secure axle housing with the lifting
device and loosen the hexagon screws.
Then separate the axle housing from the
axle drive housing.

7809AX19

② Loosen the threaded connections and

remove the releasing brake tube.

7809AX20

③ Loosen both screw necks.

7809AX21

(3) Disassembly axle drive housing

① Secure axle drive housing with the lifting
device and loosen the hexagon screws.
Then separate the axle drive housing
from the axle housing.
Eyebolt (M20) 5870 204 086
Thread insert AA00 677 715

7809AX22

3-196
② Fix axle drive housing to the assembly
truck.
Assembly truck 5870 350 000
Fixtures (2EA) 5870 350 113

7809AX76

③ Loosen cylindrical screws and lift the

releasing bearing housing with the lifting
device.
Inner extractor 5870 300 008
Eye bolt AA00 680 376

7809AX77

④ Pull the bearing outer ring (see arrow)

out of the bearing hole and remove the
shim behind.

7809AX78

⑤ Press the piston out of the bearing

housing by means of compressed air.

7809AX79

3-197
⑥ Lift differential out of the axle drive
housing with the lifting device.
Inner extractor 5870 300 008
Eye nut AA00 680 376
※ Disassembly of the various differentials
is described as of page 3-201.

7809AX80

⑦ Pull the bearing outer ring (see arrow)

out of the bearing hole and remove the
shim behind.

7809AX81

⑧ Heat slotted nut by means of hot-air

blower.
※ Slotted nut is secured with Loctite # 262.

7809AX82

⑨ Loosen the slotted nut and remove the

shim behind.
Wrench 5870 401 093
Fixing device AA00 695 905
Clamping device 5870 240 002

7809AX83

3-198
⑩ Pull input flange from the input pinion
and use a lever to lift the shaft seal ring
behind out of the axle drive housing.

7809AX84

⑪ Use a two-armed puller to press the

input pinion out of the axle drive housing
and remove the releasing tapered roller
bearing.

7809AX85

⑫ Remove the spacer and pull the tapered

roller bearing from the input pinion.
Gripping device AA00 253 881
Basic tool 5873 003 000
Clamping cylinder 5873 003 016
Pump 5870 287 010

7809AX86

⑬ Loosen the threaded connection and

remove the releasing oil tube.

7809AX87

3-199
⑭ If necessary pull the internal bearing
outer ring out of the axle drive housing
and remove the shim behind.
Assembly device AA00 696 770
Counter support 5870 300 020

7809AX88

⑮ If necessary pull the external bearing

ring out of the axle drive housing.
Assembly device AA00 696 770
Counter support 5870 300 020

7809AX89

3-200
(4) Disassembly
isassembly differentials
Disassembly
isassembly multi-disk differential lock
① Remove axial roller cage (arrow).

7809AX90

② Pull both tapered roller bearings from the

differential.
Crown wheel side
Rapid grip AA00 303 274
Basic tool 5873 004 001
Pressure piece AA00 694 360
Opposite side
Grab sleeve 5873 004 026
Basic tool 5873 004 001
Clamping cylinder 5873 003 016 7809AX91

Pump 5870 287 010

③ Preload the differential by means of the

press and loosen the locking screws.
Pressure piece AA00 694 360

7809AX92

④ Lift the differential cover from the

differential housing by means of the
lifting device.
Inner extractor 5870 300 008
Eye nut AA00 680 376

7809AX93

3-201
⑤ Preload the compression spring by
means of the press and disengage the
retaining ring.
Then pull the sliding sleeve out of the
differential cover and remove the
releasing compression springs.

7809AX94

⑥ Remove single parts.

1 = Disk
2 = Pressure piece
3 = Cage
4 = Lever (15EA)
5 = Disk carrier
6 = Disk package

7809AX95

⑦ Loosen hexagon screws and remove the

releasing disk.

7809AX96

⑧ Remove thrust washer and axle bevel

gear from the differential housing.

7809AX97

3-202
⑨ Force out slotted pins (4EA).

7809AX98

⑩ Pull spider shafts (4EA) and remove the

releasing spider gears with the thrust
washers from the differential housing.

7809AX99

⑪ Remove the axle bevel gears and the

shims behind.

7809AX100

⑫ Support the crown wheel and force out

the differential housing.

7809AX101

3-203
2) ASSEHBY
(1) Assembly differentials
Assembly multi-disk differential lock
① Mount two adjusting screws and press
the heated crown wheel onto the
differential housing until contact is
obtained.
Adjusting screws 5871 204 040
7809AX102

② Insert disk and thrust washer into the

differential housing

7809AX103

③ Insert axle bevel gear.

7809AX104

④ Insert spider gears with thrust washers

into the differential housing and fix them
with the spider shaft.
※ Thrust washers must be positioned with
the tabs (see arrow 1) in the recesses of
the differential housing.
Pay attention to radial installation position
of the spider shafts (fixing holes, arrow
2).
7809AX105

3-204
⑤ Fix spider shafts with slotted pins (2
pieces / hole).
※ Press the slotted pins with 180° offset
openings into flush position.

7809AX106

⑥ Mount second axle bevel gear and thrust

washer.

7809AX107

⑦ Mount disk and fix it with hexagon

screws.
· Tightening torque (M10/10.9) :
5.1 kgf·m (36.9 lbf·ft)

7809AX108

3-205
 Setting of disk package
⑧ Premount single parts according to the
adjacent sketch.
1 = Differential cover
2 = Pressure piece
3 = Disk
4 = Cage
5 = Lever (15EA)
6 = End plate
7809AX109
7 = Outer disks (optional)
8 = Inner disks

⑨ Preload disk package with an axial force

of F = 7 ton.
Then check the setting dimension A =
15.5 - 0.2 mm from the mounting face of
the differential cover to the plane face of
the outer disk (see also below sketch).
※ Any deviation from the specified setting
dimension must be corrected with a
corresponding outer disk.
7809AX110

Legend to sketch:
A = Setting dimension = 15.5 -0.2 mm

7809AX111

⑩ Engage the snap ring (see arrow) into

the annular groove of the disk carrier.

7809AX112

3-206
⑪ Insert the premounted disk carrier onto
the axle bevel gear.

7809AX113

⑫ Mount outer and inner disks.

※ For the number of disks and disk
arrangement please refer to the parts
manual.
※ Pay attention to the radial installation
position of the disk package, as shown
on the adjacent figure.

7809AX114

⑬ Insert end plate.

7809AX115

⑭ Mount cage and lever (15EA).

7809AX116

3-207
⑮ Insert pressure piece (see arrow) and
install disk.

7809AX117

16 Insert compression springs (6EA) into

the differential cover.

7809AX118

17 Insert sliding sleeve.

7809AX119

18 Preload the compression springs by

means of the press and engage the
retaining ring into the annular groove of
the sliding sleeve.

7809AX120

3-208
19 Mount two adjusting screws and insert
the differential cover by means of the
lifting device.
Adjusting screws 5870 204 040
Inner extractor 5870 300 008
Eye nut AA00 680 376

7809AX121

20 Preload the differential by means of the

press and bolt with new locking screws.
· Tightening torque (M16/12.9) :
40.7 kgf·m (295 lbf·ft)
Pressure piece AA00 694 360

7809AX122

21 Heat both tapered roller bearings and

insert until contact is obtained.
※ Adjust tapered roller bearing after
cooling down.

7809AX123

22 Insert axial roller cage (see arrow).

7809AX124

3-209
(2) Assembly axle drive housing
※ If crown wheel or input pinion are
damaged, both parts must be jointly
replaced.
In case of a new installation of a
complete bevel gear set pay attention to
an identical mating number of input
pinion and crown wheel.

Determination
etermination of shim thickness to
obtain a correct contact pattern
※ The following measuring procedures
must be carr ied out with utmost
accuracy.
Inaccurate measurements lead to an
incorrect contact pattern requiring an
additional disassembly and reassembly
of input pinion and differential.

① Read dimension I from the axle drive

housing.
Dimension I e.g . . . . . . . . . . . . 331.25 mm

7809AX125

② Read dimension II (pinion dimension).

Dimension II e.g . . . . . . . . . . . 265.00 mm

7809AX126

3-210
③ Determine dimension III (bearing width).
Dimension III e.g. . . . . . . . . . . . . 63.60 mm
Calculation example A :
Dimension I . . . . . . . . . . . . . . . . 331.25 mm
Dimension II . . . . . . . . . . . . . . - 265.00 mm
Dimension III . . . . . . . . . . . . . . - 63.60 mm
Difference = shim s = 2.60 mm

7809AX127

Reassembly of input pinion

① Undercool the external bearing outer

ring and insert it into the axle drive
housing until contact is obtained.
Driver tool 5870 050 007
Handle 5870 260 004

7809AX128

② Insert the determined shim e.g. s = 2.60

mm into the housing hole.

7809AX129

③ Undercool the internal bearing outer ring

and bring it into contact position in the
housing hole by using the assembly
fixture.
Assembly fixture AA00 623 955

7809AX130

3-211
④ Heat the tapered roller bearing and
insert it into the input pinion until contact
is obtained.

7809AX131

Setting of rolling torque of input pinion

bearing 0.1~0.5 kgf
kgf·m (without shaft seal
ring)
⑤ Insert spacer (e.g. s = 7.13 mm).
※ According to our exper ience the
necessary rolling torque is obtained
when reusing the spacer which has been
removed during disassembly (e.g. s =
7.13 mm).
7809AX132
A later check of the rolling torque,
however, is absolutely necessary.

⑥ Insert the preassembled input pinion into

the axle drive housing and insert the
heated tapered roller bearing until
contact is obtained.

7809AX133

⑦ Press the protection plate onto the input

flange (see arrow) until contact is
obtained.
※ Do not fit the shaft seal ring until the
contact pattern has been checked (page
3-218).

7809AX134

3-212
⑧ Insert input flange and fix it by means of
disk and slotted nut.
ᆞTightening torque :
122 kgf·m (885 lbf·ft)
Wrench 5870 401 093
Fixing device AA00 695 905
Clamping device 870 240 002
※ Preliminarily mount slotted nut without
Loctite. 7809AX135

※ While tightening rotate the input pinion

several times in both directions.

⑨ Check rolling torque (0.15~0.51 kgf·m

without shaft seal ring).
※ When installing new bearings try to
achieve the upper value of the rolling
torque.
※ In case of deviations from the necessary
rolling torque correct with a corresponding
spacer (figure AX132, page 3-212) as
specified below. 7809AX136
Insufficient rolling torque - install thinner
spacer ring.
Excessive rolling torque - install thicker
spacer ring.

⑩ Mount threaded connection.

ᆞTightening torque :
10.2 kgf·m (73.8 lbf·ft)

7809AX137

3-213
⑪ Mount oil tube.
ᆞTightening torque :
10.2 kgf·m (73.8 lbf·ft)

7809AX138

⑫ Grease O-rings (see arrows) and insert

them into the annular grooves of the
piston.

7809AX139

⑬ Insert piston (see arrow) into the bearing

housing until contact is obtained.

7809AX140

3-214
 Determination
etermination of shims for setting of
bearing rolling torque (differential
housing) and backlash (bevel gear set)
※ Determine the required shims on the basis
of the read value (deviation/test dimension)
and the corresponding specifications of the
table below: (KRS – SET – RIGHT) (KRS =
bevel gear set):
① Deviation see crown wheel rear side.
7809AX141

The test dimension 108 is stamped into

the crown wheel rear side. If no + or –
deviation is indicated, this value
corresponds to the actual value 0 in the
table below. According to this value, the
required shims are allocated in the table
below.
※ A ny + o r – d ev i a t i o n o f t h e t e s t
dimension caused by production is also
marked on the crown wheel rear side
(e.g.- 20 or - 10 or 10 or 20) . 7809AX142

In accordance with this deviation, the

required shims are allocated in the table
below.
Legend to sketch:
1 = Bearing housing
2 = Shim (crown wheel side)
3 = Shim (differential carrier side)
4 = Axle drive housing

Shims for differential

Crow wheel
- 30 - 20 - 10 0 10 20
marking
Deviation - 0.3 - 0.2 - 0.1 0 0.1 0.2
Shim
diff cage side 1.1 1.2 1.3 1.4 1.5 1.6
shim thickness
Shim
ZGAQ-03681 ZGAQ-03676 ZGAQ-03677 ZGAQ-03678 ZGAQ-03679 ZGAQ-03680
P/No.
Shim
crown wheel side 1.7 1.6 1.5 1.4 1.3 1.2
shim thickness
Shim
ZGAQ-03687 ZGAQ-03686 ZGAQ-03685 ZGAQ-03684 ZGAQ-03683 ZGAQ-03682
P/No.

3-215
② Insert the determined shim (e.g. s = 1.4
mm) into the hole of the axle drive
housing and reset until contact with the
bearing outer ring is obtained.

7809AX143

③ Cover some drive and coast flanks of the

crown wheel with marking ink.
Then insert the premounted differential
into the axle drive housing.
Inner extractor 5870 300 008
Eye nut AA00 680 376

7809AX144

④ Insert the determined shim (e.g. s = 1.4

mm) into the bearing housing and reset
the bearing outer ring until contact is
obtained.

7809AX145

⑤ Place the premounted bearing housing

onto the axle drive housing by means of
the lifting device.
Inner extractor 5870 300 008
Eye nut AA00 680 376
※ Preliminarily mount the bearing housing
without O-ring.

7809AX146

3-216
⑥ Fix the bearing housing by means of
cylindrical screws (3EA).
ᆞTightening torque (M12/10.9) :
5.1 kgf·m (36.9 lbf·ft)

7809AX147

Leakage test of lock

⑦ Pressurize the lock (p = 1 bar), close
shut-off valve and remove air line.
※ No noticeable pressure loss is allowed to
occur within 10 sec.

7809AX148

⑧ By rotating the input flange, roll crown

wheel over the input pinion in both
directions several times.
Then remove the bearing housing again
and lift the differential out of the axle
drive housing.
Compare the obtained contact pattern
with contact pattern.
※ In case of any contact pattern deviation,
a measuring error was made when 7809AX149

determining the shim (Figure AX129,

page 3-211), which must be corrected by
all means.

⑨ After the contact pattern check insert the

differential again into the axle drive
housing.

7809AX150

3-217
 Reassembly of shaft seal ring (figure
AX151~153)
⑩ Loosen slotted nut and pull the input
flange from the input pinion.
Wrench 5870 401 093
Fixing device AA00 695 905
Clamping device 5870 240 002

7809AX151

⑪ Mount the shaft seal ring with the seal lip

showing to the oil chamber.
Driver tool AA00 623 986
※ The exact installation position of the
shaft seal ring is obtained when using
the specified driver tool.
※ Wet the outer diameter of the shaft seal
ring with spirit directly before installation
and fill the space between seal and dust 7809AX152

lip with grease.

⑫ Insert input flange and finally tighten by

means of disk and slotted nut.
·Tightening torque :
122 kgf·m (12.5 lbf·ft)
Wrench 5870 401 093
Fixing device AA00 695 905
Clamping device 5870 240 002
※ Cover the thread of the slotted nut with
loctite #262. 7809AX153

⑬ Grease O-ring (see arrow) and insert it

into the annular groove of the bearing
housing.

7809AX154

3-218
⑭ Insert the bearing housing by means of
the lifting device and finally tighten it with
cylindrical screws.
·Tightening torque (M12/10.9) :
5.1 kgf·m (36.9 lbf·ft)

7809AX155

⑮ Grease O-rings (see arrows) and insert

them on both sides of the axle drive
housing.

7809AX156

16 Mount two adjusting screws and bring

axle drive housing in contact position
with the axle housing by using the lifting
device.
Then fix the axle drive housing with
hexagon screws.
·Tightening torque (M20/10.9) :
57.1 kgf·m (413 lbf·ft)
Adjusting screws (M20) 5870 204 024
Eye bolt (M20) 5870 204 086 7809AX157

Thread insert AA00 677 715

※ After mounting the axle drive housing
unbolt the suppor t until contact is
obtained.

3-219
(3) Assembly axle housing

① Mount both fittings.

·Tightening torque : 3.67 kgf·m
(26.6 lbf·ft)

7809AX158

② Mount brake tube.

·Tightening torque : 10.2 kgf·m
(73.8 lbf·ft)

7809AX159

③ Mount two adjusting screws and bring

the axle housing into contact position
with the axle drive housing by using the
lifting device.
Then fix the axle housing by means of
hexagon screws.
·Tightening torque (M20/10.9) :
57.1 kgf·m (413 lbf·ft)
Adjusting screws (M20) 5870 204 024
7809AX160

※ After assembling the axle housing

secure the axle with clamping brackets.

3-220
(4) Aeassembly output and brake
① Pull in wheel stud into the output shaft
until contact is obtained.
Wheel stud puller - basic tool
5870 610 001
Insert (M22x1.5) 5870 610 002
※ Special tool may only be used for repair
solution when exchanging individual
wheel studs with mounted output shaft. 7809AX28

When using a new output shaft, mount

the wheel studs with the press.

② Heat tapered roller bearing and insert it

into the output shaft until contact is
obtained.

7809AX29

② Wet O-ring of the slide ring seal and

locating hole with spirit.
Snap new slide ring seal (1) into the
output shaft.
Then mount new slide ring seal (part 2)
accordingly into the brake housing.
※ For the installation position of the seal
please also refer to sketch AX34, page
3-223.
7809AX30
※ The surface of the slide ring seal may not
have any grooves, scratches or other
types of damage. Take care that the
sealing surface is parallel to the housing
face.
The O-rings must be mounted evenly
into the locating hole and must not bulge
out of the hole. Risk of injury - Metal
rings have extremely sharp edges. Wear
protective gloves.

7809AX31

3-221
③ Insert the premounted brake housing by
means of the lifting device over the
output shaft until contact is obtained.
※ Before clamping the seal rings to
installation dimension, clean the sliding
surfaces and apply an oil film. We
recommend to use a leather cloth
soaked with oil.

7809AX31

④ Insert back-up rings and grooved rings

into the annular grooves of the brake
housing (see arrows).
※ Pay attention to the installation position;
please also refer to sketch AX34, page
3-223.

7809AX32

⑤ Clean the annular groove of the brake

housing with spirit.
Then insert the guide ring into the
annular groove (see also the following
sketch) and fix it with loctite #415 at its
extremities (see arrows).
※ The full circumference of the guide ring
must be in an exact contact position.
※ Upon installation the orifice of the guide
7809AX33
ring must show upwards (12 o’clock).

3-222
 Legend to sketch:
1 = Brake housing 1
2 = Guide ring
3 = Back-up ring
4 = Grooved ring
5 = Grooved ring
2
6 = Back-up ring 3
7 = Slide ring seal 4
5
8 = Output shaft
6

7809AX34

⑥ Insert the piston into the brake housing

and carefully install with the fixing device
until contact is obtained.
Fixing device AA00 680 530
※ Sufficiently oil seal surface of piston/
back-up rings, grooved rings and guide
ring (W-10 oils to be used).

7809AX35

⑦ Insert cup spring into the piston with the

convex side showing upwards.

7809AX36

3-223
⑧ Inser t disk and fix it by means of
hexagon screws.
·Tightening torque (M8/10.9) :
3.47 kgf·m (25.1 lbf·ft)

7809AX37

⑨ Mount outer and inner disks.

※ For the number of disks and the disk
arrangement please refer to the relating
spare parts list.

7809AX38

⑩ Insert end plate.

7809AX39

Setting of installation dimension 57.25~

57.79 mm
⑪ Measure installation dimension from the
mounting face of the brake housing to
the front face of the end plate.
Installation dimension e.g . . . . . 57.50 mm
※ Any deviation from the necessary
installation dimension must be corrected
with an appropriate outer disk (see spare 7809AX40

parts manual).

3-224
⑫ Press stop bolt into the cover until
contact is obtained.
Then insert the premounted cover into
the planetary carrier until contact is
obtained.
Legend to sketch:
1 = Stop bolt
2 = Cover
3 = Planetary carrier
7809AX161

⑬ Insert the cylindrical roller bearing into

the planetary gear – for this purpose
press the cylindrical roller bearing
through the packaging sleeve until the
snap ring engages into the annular
groove of the planetary gear.
※ Use packaging sleeve to facilitate
assembly.
1 = Cylindrical roller bearing
7809AX162
2 = Packaging sleeve
3 = Snap ring
4 = Planetary gear

⑭ Heat bearing inner rings and insert the

premounted planetary gears with large
radius facing the planetary carrier
(downwards) until contact is obtained.
※ Adjust bearing inner rings after cooling
down.
Then fix planetary gears by means of
retaining rings.
7809AX163

⑮ Heat tapered roller bearing and install it

to the planetary carrier until contact is
obtained.

7809AX164

3-225
16 Wet front face (contact face bearing
inner ring, arrow 1) and profile (teeth,
arrow 1) in the output shaft with anti-
1
corrosive agent. 2

7809AX41

17 Align disk package centrally and radially.

Then insert the planetary carrier by
means of the lifting device into the teeth
of the output shaft until contact is
obtained.

· Rear axle (planetary carrier with 3

planetary gears)
Inner extractor 5870 300 019
Eye bolt 5870 204 073
7809AX42
· Front axle (planetary carrier with 4
planetary gears)
Inner extractor 5870 300 008
Eye nut AA00 680 376

18 Pivot output 90°.

Insert disk and fix planetary carrier with
new locking screws.
※ Tighten locking screws successively with
a tightening torque of 20.4 kgf·m (147.5
lbf·ft).
Then retighten the locking screws
successively with a tightening torque of
51 kgf·m (369 lbf·ft).
7809AX43

3-226
19 Install O-ring (see arrow) to the cover.

7809AX44

20 Insert the cover into the output shaft until

contact is obtained.

7809AX45

Set the axial play of the sun gear shaft

0.5~2.0 mm
20 Determine dimension I, from the mounting
face of the brake housing to the front face
of the stop bolt.
Dimension I e.g. . . . . . . . . . . . . . 58.60 mm
Gauge blocks 5870 200 066
Straightedge 5870 200 022
7809AX46

21 Insert stub shaft into the teeth of the axle

bevel gear until contact is obtained.
※ Pay attention to the installation position;
mount the stub shaft with the long teeth
showing to the differential.

7809AX47

3-227
22 Insert the sun gear shaft until contact is
obtained.

7809AX48

23 Measure dimension II, from the front face

of the sun gear shaft to the mounting
surface of the axle housing.
Dimension II e.g. . . . . . . . . . . . . 56.60 mm
Straightedge 5870 200 022
Calculation example :
Dimension I . . . . . . . . . . . . . . . . 58.60 mm
Dimension II . . .. . . . . . . . . . . . . - 56.60 mm
Difference . . . . . . . . . . . . . . . . . . 2.00 mm 7809AX49

Required axial play e.g. . . . . . . - 1.00 mm

Difference = shim e.g. s = 1.00 mm

24 Insert sun gear shaft into the planetary

carrier.

7809AX50

25 Fix determined shim e.g. s = 1.00 mm

with grease into the sun gear shaft.

7809AX51

3-228
26 Fix O-ring (see arrow) with grease into
the countersink of the brake housing.

7809AX52

27 Grease O-ring (see arrow) and install it

to the axle housing.

7809AX53

28 Mount two adjusting screws and use the

lifting device to bring the output into
contact position with the axle housing.
Then fix the output by means of hexagon
screws.
·Tightening torque (M20/10.9) ;
57.1 kgf·m (413 lbf·ft)
Adjusting screws (M20) 5870 204 024
Load-carrying device AA00 685 875
7809AX54

※ Fix load carrying device with wheel stud.

29 Mount breather (see arrow).

7809AX55

3-229
30 Check brake hydraulics for leakages.

※ Before starting the test, completely

breathe the brake hydraulics.
Then pressurize the brake temporarily
(5EA) with p = 100 bar max.
High-pressure test :
Build up test pressure p = 100 -10 bar
max. and close connection to HP pump
via shut-off valve.
7809AX56
A pressure drop of max. 2 % (2 bar) is
permissible during a 5 minute testing
time.
Low-pressure test :
Low-pressure
Reduce test pressure p = 5 bar and
close shut-off valve.
No pressure drop is allowed during a 5
minute testing time.
Test media
media :
Engine oils SAE 10-W
HP pump 5870 287 007
Clutch 0501 207 939
Reduction (M18x1.5) 5870 950 161
Oil collector bottle 5870 286 072

31 Check operability of differential hydraulic

lock
Build up pressure p = 20 bar max. and
close connection to HP pump via shut-off
valve.
Lock on:
When rotating the input flange, both
outputs must have the same direction of
rotation.
7809AX165

Lock off:
When rotating the input flange one side
holds or has the opposite direction of
rotation.
※ Prior to putting the axle into operation, fill
it with oil according to the related
lubrication and maintenance instructions.

3-230
 SECTION 4 BRAKE SYSTEM

Group 1 Structure and Function -------------------------------------------------------------------------------------- 4-1

Group 2 Operational Checks and Troubleshooting -------------------------------------------------------- 4-29
Group 3 Tests and Adjustments -------------------------------------------------------------------------------------- 4-36
Group 4 Disassembly and Assembly ------------------------------------------------------------------------------ 4-38
 SECTION 4 BRAKE SYSTEM
GROUP 1 STRUCTURE AND FUNCTION

1. OUTLINE
※ The brakes are operated by a pressure compensated, closed center hydraulic system.
Flow is supplied by a fixed displacement, gear type brake pump.

BRAKE SYSTEM
The fixed displacement brake pump supplies flow to the cut-off valve for service brake circuit and
park brake circuits. It flows to three accumulator. The accumulator has a gas precharge and an
inlet check valve to maintain a pressurized volume of oil for reserve brake applications.
Oil through the accumulator flows to the brake valves. The brake valve is a closed center design,
dual circuit operated by a pedal.
The front and rear brakes will operate simultaneously with only one brake pedal depressed.
The differential contains annular brake piston and double sided disk.
Brake pump flow also goes to the parking brake solenoid valve in cut-off valve.
The brake system contains the following components:
·Brake pump
·Parking brake solenoid valve in cut-off valve
·Cut-off valve
·Brake valve
·Accumulators
·Pressure switches

4-1
FULL POWER HYDRAULIC BRAKE
SYSTEM
ADVANTAGES - The full power hydraulic Response time
brake system has several advantages over Full power brake actuation VS
Air/Hydraulic brake actuation
traditional brake actuation systems. These
systems are capable of supplying fluid to a 1000
range of very small and large volume
service brakes with actuation that is faster 900
than air brake systems. Figure represents 800
a time comparison between a typical air/ Brake pressure
700 (Full power)

Brake torque(lb·in)
hydraulic and full power hydraulic brake
actuation system. 600
Brake pressure
Full power systems can supply significantly 500 (Air/hydraulic)
higher brake pressures with relatively low Brake torque
400
reactive pedal forces. The reactive pedal (Air/hydraulic)
force felt by the operator will be proportional 300
Brake torque
to the brake line pressure being generated. 200 (Full power)
This is referred to as brake pressure
modulation. 100
Another key design feature of full power
0 1 2 3 4
systems is the ability to control maximum
brake line pressure. In addition, because Time(seconds)
these systems operate with hydraulic oil,
filtration can be utilized to provide long
component life and low maintenance
operation.
Because these systems are closed center,
by using a properly sized accumulator,
emergency power-off braking that is
identical to power-on braking can be
achieved. These systems can be either
dedicated, where the brake system pump
supplies only the demands of the brake
system or non-dedicated, where the pump
supplies the demands of the brake system
as well as some secondary down stream
hydraulic device.
Another important note is that all seals
within these system must be compatible
with the fluid medium being used.

4-2
2. HYDRAULIC CIRCUIT

Parking
T/M
40
22
Front

20 20 P1
A1
T1

P2
39
A2 23
T2

20 19 B1 A1 B2 A2

Rear
A3

21
PS

T1
PS
Return line
B

21
PS

PS1

P T
25
Return line
30
26
Fan drive motor
27 3
T/M
Return line 29
28
Return line
24
Main pump

78094BS01

3 Fan & brake pump 23 Pressure switch 28 Strainer

19 Cut-off valve 24 Hydraulic tank 29 Oil cooler
20 Accumulator 25 Air breather 30 Pressure filter
21 Pressure sensor 26 Return filter 39 Axle
22 Brake valve 27 Bypass valve 40 Parking brake at T/M

4-3
 1) SERVICE BRAKE RELEASED

Parking
T/M
40
22
Front

20 20 P1
A1
T1

P2
39
A2 23
T2

20 19 B1 A1 B2 A2

Rear
A3

21
PS

T1
PS
Return line
B

21
PS

PS1

P T
25
Return line
30
26
Fan drive motor
27 3
T/M
Return line 29
28
Return line
24
Main pump

78094BS02

When the pedal of brake valve (22) is released, the operating force is eliminated by the force of the
spring, and the spool is returned.
When the spool removes up, the drain port is opened and the hydraulic oil in the piston of axles
return to the tank (24).
Therefore, the service brake is kept released.

4-4
 2) SERVICE BRAKE OPERATED

Parking
T/M
40

22 Front

20 20 P1
A1
T1

P2
39
A2 23
T2

20 19 B1 A1 B2 A2

Rear
A3

21
PS

T1
PS
Return line
B

21
PS

PS1

P T
25
Return line
30
26
Fan drive motor
27 3
T/M
Return line 29
28
Return line
24
Main pump

78094BS03

When the pedal of brake valve (22) is depressed, the operating force overcomes the force of the
spring, and is transmitted to the spool. When the spool moves down, the inlet port is opened, and
at the same time the hydraulic oil controlled the pressure level by the cut-off valve (19) enters the
piston in the front and rear axles. Therefore, the service brake is applied.

4-5
 3) PARKING BRAKE RELEASED

Parking
T/M
40
22
Front
B
A 20 20 P1
A1
T1

39
P

P2
A2 23
T2

Parking brake switch 20 19 B1 A1 B2 A2

Rear
A3

21
PS

T1
PS
Return line
B

21
PS

PS1

Parking brake P T
25 solenoid
Return line
30
26
Fan drive motor
27 3
T/M
Return line 29
28
Return line
24
Main pump

78094BS04

When the parking brake switch is pressed A position, the solenoid valve is energized and the
hydraulic oil controlled the pressure level by the cut-off valve (19) enters the parking brake. It
overcomes the force of the spring and pushes the piston rod. This releases the brake.
Therefore, the hydraulic oil pressure is applied to the parking brake piston through the solenoid
valve and the parking brake is kept released.

4-6
 4) PARKING BRAKE OPERATED

Parking
T/M
40
22
Front
B
A 20 20 P1
A1
T1

39
P

P2
A2 23
T2

Parking brake switch 20 19 B1 A1 B2 A2

Rear
A3

21
PS

T1
PS
Return line
B

21
PS

PS1

Parking brake P T
25 solenoid
Return line
30
26
Fan drive motor
27 3
T/M
Return line 29
28
Return line
24
Main pump

78094BS05

When the parking brake switch is pressed B position, the solenoid valve is deenergized and the
valve open the drain port.
At the same time, the hydraulic oil in the parking brake return to the tank through the solenoid
valve. When the piston rod is returned by the force of the spring, the parking brake is applied.

4-7
3. BRAKE PUMP (+FAN PUMP)
1) STRUCTURE

26

Fan pump
28
25
24
18
5
8

14
11
3 10 16
21
22 13 27
29

20
9
6

19
15
12
2
1

4 Brake pump
7

23 17

78094BS06

1 Body 11 Screw 21 Shaft seal

2 Rear cover 12 Screw 22 Ring
3 Front cover 13 Nut 23 Ring
4 Thrust plate 14 Screw 24 Ring
5 Bushing 15 Washer 25 Sleeve bearing
6 Drive gear 16 Washer 26 Hub
7 Driven gear 17 Seal 27 Dowel pin
8 Drive shaft 18 Seal 28 Steel bushing
9 Driven gear 19 Seal 29 Housing
10 Stud bolt 20 Seal

This gear pump have a maximum delivery pressure of 150 kgf/cm2.

The pressure loaded type gear pump is designed so that the clearance between the gear and the
bushing can be automatically adjusted according to the delivery pressure. Therefore, the oil leakage
from the bushing is less than that in the case of the fixed bushing type under a high discharge pressure.
Consequently, no significant reduction of the pump delivery occurs, even when the pump is operated
under pressure.

4-8
2) PRINCIPLE OF OPERATION
(1) Mechanism for delivering oil
The drawing at r ight shows the
operational principle of an external gear
pump in which two gears are rotating in
mesh.
The oil entering through the suction port Suction Discharge
is trapped in the space between two gear
teeth, and is delivered to the discharge
port as the gear rotates.
Except for the oil at the bottom of the gear
teeth, the oil trapped between the gear
teeth, is prevented from returning to the
suction side with the gears in mesh.
Since the gears are constantly delivering
oil, the oil delivered to the discharge port
is forced out of the port.
The amount of discharge increases with
the speed of rotation of the gear.
If there is no resistance in the oil passage
into which the discharged oil flows, the oil
merely flows through the passage,
producing no increase in pressure.
If however, the oil passage is blocked with
something like a hydraulic cylinder, there
will be no other place for the oil to flow, so
the oil pressure will rise. But the
pressure which rises in this way will never
go higher, once the hydraulic cylinder
piston starts moving because of the oil
pressure.
As described earlier, the pump produces
the oil flow, but not the oil pressure. We
can therefore conclude that pressure is a
consequence of load.
In other words, the pressure depends on
a counterpart.

(770-3ATM) 4-9

4-9
(2) Internal oil leakage
Oil leaks from a place under higher
pressure to a place under lower pressure,
provided that a gap or a clearance exists
in between.
In the gear pump, small clearances are
provided between the gear and the case
and between the gear and the side plate
to allow the oil to leak out and to serve as
a lubricant so that the pump will be rge
protected from seizure and binding. ischa
D
The drawing at right shows how the
leaked oil flows in the pump. As such,
there is always oil leakage in the pump
from the discharge side (under higher
pressure) to the suction side. The delivery
n
of the pump is reduced by an amount uctio
S
equal to the pump discharge.
In addition, the delivery of the pump will
also decrease as the amount of oil
leakage increases because of expanded
radial clearance resulting from the wear of
pump par ts, the lower oil viscosity
resulting from increases in the oil
temperature, and the initial use of low
(770-3ATM) 4-10
viscosity oil.

4-10
(3) Forces acting on the gear
The gear, whose outer surface is
subjected to oil pressure, receives forces
jointing towards its center.
Due to the action of the delivery pressure,
the oil pressure in higher on the delivery
side of the pump, and due to suction
pressure, is lower on the suction side. In
the intermediate section, the pressure will
gradually lower as the position moves
from the delivery side to the suction side. Drive gear
This phenomenon is shown in the
drawing at right.
In addition, the gears in mesh will receive Suction Discharge
interacting forces. side side
These forces pushing the gears toward
the suction side are received by the
bearings. Since the gears are pressed Driven gear
toward the suction side by these forces,
the radial clearance becomes smaller on
the suction side in the case. In some
pumps, the clearance may become zero, Pressure distribution
thus allowing the gear teeth and the case
to come into light contact.
For this reason, an excessive increase in
the delivery pressure must be avoided,
since it will produce a large force which
will act on the gears, placing an overload
on the bearings, and resulting in a
shortened service life of the bearing or
(770-3ATM) 4-11
interference of the gear with the case.

4-11
4. BRAKE VALVE
1) STRUCTURE

35
34
28

29
30
31
32 27
33
26

14 25

34 24
35 23
11
22
10
9
8 21

7 20

19
6
18
5
4 17
3 16
2 15
1
75794BS07

1 Plug 15 Spacer 27 Boot

2 Retainer 16 Retaining ring 28 Left pedal and base assy
3 O-ring 17 Retainer 29 Sensor
4 Spring 18 Shim 30 Washer
5 Cap screw 19 Spring 31 Cap screw
6 Washer 20 Spring 32 Cover
7 Housing 21 Spring 33 Screw
8 Lower spool 22 Piston 34 Lever assy (option)
9 O-ring 23 Quad ring 35 Right pedal and base assy
10 O-ring 24 O-ring (option)
11 Upper spool 25 Retainer
14 Housing 26 Cup

4-12
2) OPERATION

Left pedal and base assy Right pedal and base assy(opt)

A1 A

A2

Test connection

P1
A1
T1 T1
P1
P2
T2
A2
T2 Pressure switch P2

Hydraulic circuit
VIEW A - A

Port Port name Port size

P1, P2 Pressure port 3/4-16UNF
T1, T2 Return port 3/4-16UNF
A1, A2 Brake cylinder port 3/4-16UNF
75794BS08

· Brake pressure specification : 80±5 bar (1160±70 psi)

4-13
(1) Purpose
The purpose of the brake valve is to sensitively increase and decrease the braking pressure
when the brake pedal is actuated.
(2)
2) Ready position
When the braking system is ready for operation, its accumulator pressure acts directly on ports
(P1, P2) of the brake valve. A connection is established between ports (A1, A2) and ports (T1,
T2) so that the wheel brakes ports (A1, A2) are pressureless via the returns ports (T1, T2).
(3) Partial braking
(3
When the brake valve is actuated, an amount of hydraulic pressure is output as a ratio of the foot
force applied.
The spring assembly (21) beneath base (28) is designed in such a way that the braking pressure
changes depending on the angle. In the lower braking pressure range, the machine can be
slowed sensitively.
When the braking process is commenced, the upper spool is mechanically actuated via spring
assembly (21), and the lower spool is actuated hydraulically by spool. As spools (11, 8) move
downward, they will first close returns (T1, T2) via the control edges, thus establishing a
connection between accumulator ports (P1, P2) and ports (A1, A2) for the wheel brake cylinders.
The foot force applied now determines the output braking pressure. The control spools(11, 8)
are held in the control position by the force applied (Spring assembly above the spools and the
hydraulic pressure below the spool (Balance of forces).
After output of the braking pressure, spools (11, 8) are in a partial braking position, causing ports
(P1, P2) and ports (T1, T2) to close and holding the pressure in ports (A1, A2).
(4) Full braking position
(4
When pedal is fully actuated, end position of the brakes is reached and a connection established
between accumulator ports (P1, P2) and brake cylinder ports (A1, A2). Returns (T1, T2) are
closed at this point.
When the braking process is ended, a connection is once again established between brake
cylinder ports (A1, A2) and return ports (T1, T2), closing accumulator ports (P1, P2).
The arrangement of spools in the valve ensures that even if one braking circuit fails the other
remains fully operational. This is achieved by means of the mechanical actuation of both spools
and requires slightly more pedal travel.
(5) Failure of a circuit
In the event of the lower circuit failing, the upper circuit will remain operational. Spring assembly
(21) will mechanically actuate spool. In the event of the upper circuit failing, the lower circuit will
remain operational since the lower spool (8) is mechanically actuated by spring assembly (21)
and spool (11).
(6) Installation requirements
Return lines (T1, T2) must be connected directly to the tank.
The connecting lines must be installed is such a way as to permit proper bleeding.

4-14
(7) Maintenance of the brake valve
No special maintenance beyond the legal requirements is necessary.
When using high-pressure cleaners on the machine, please make sure that the water jet is not
aimed directly at the brake valve (to prevent damaging the bellows).
For safety reasons the whole of the brake valve must be replaced if parts other than those
listed above are damaged.
(8) Repair work
(8
When working on the braking system, always make sure that there is absolutely no pressure
in the system. Even when the engine is switched off there will be some residual pressure in
the system.
※ When doing repair work, make sure your environment is very clean.
Immediately close all open ports on the components and on pipes using plugs.
(9) Replacing the complete actuating mechanism
Carefully clamp the unit vertically in a fixture. The actuating mechanism can be removed by taking
out the three bolts. Make sure that spring assembly (21) does not fall out. When installing the new
actuating mechanism, make sure that spring assembly (21) is fitted in the right order. Tighten the
three bolts (5).

4-15
5. CUT-OFF VALVE
1) STRUCTURE

3 C B
1
7
D D
2

P PS1
A A
C B
SECTION A - A SECTION B - B

B1 A1 B2 A2
6
A1 A2
A3
PS
T1
PS T1

B
B1 B2
4 PS1
A3
B
P T

SECTION C - C SECTION D - D Hydraulic circuit

75794BS20

1 Manifold 5 Check valve Part name Port size

2 Solenoid valve 6 Cut-off valve P, T PF 1/2
3 Coil 7 Relief valve A1, A2, A3, B, B1, B2, T1 PF 3/8
4 Check valve PS, PS1 PF 1/4

2) OPERATION
When the pump works, the oil under the pressure flows into P port.
The oil in P port is stored in the accumulator on A3 port.
As the pressure on P line rises to 150bar, the cut off valve (6) starts cut-offing and the oil in the P
port is unloaded. The pressure on P line goes down 120 bar by the minute leakage from valve and
other factors.
At this pressure, the cut-off valve starts cut-ining.
This process is repeated in the regular period of 30~40 seconds.

4-16
6. BRAKE ACCUMULATOR
1) STRUCTURE

31LL-40020
Item
(item20)
Diameter 167 mm
Mounting height 219 mm
Norminal volume 2.0ℓ
Priming pressure 50 kgf/cm2
B Operating medium Oil
Operating pressure Max 210 kgf/cm2
A Thread M22×1.5
Priming gas Nitrogen
C
A Fluid portion C Diaphragm
B Gas portion D Valve disk
D

75794BS09

2) OPERATION
(1) Purpose
Fluids are practically incompressible and are thus incapable of accumulating pressure energy. In
hydropneumatic accumulators, the compressibility of a gas is utilized to accumulate fluid. The
compressible medium used in the accumulators is nitrogen.
In braking systems, the purpose of the accumulators is to store the energy supplied by the
hydraulic pump. They are also used as an energy reserve when the pump is not working, as a
compensator for any losses through leakage, and as oscillation dampers.
(2) Operation
(2
The accumulator consists of a fluid portion (A) and a gas portion (B) with a diaphragm (C) as a
gas-tight dividing element. The fluid portion (A) is connected to the hydraulic circuit, causing the
diaphragm accumulator to be filled and the gas volume to be compressed as the pressure rises.
When the pressure falls, the compressed gas volume will expand, thus displacing the
accumulated pressure fluid into the circuit.
The diaphragm bottom contains a valve disk (D) which, if the diaphragm accumulator is
completely empty, closes the hydraulic outlet, thus preventing damage to the diaphragm.
3) Installation requirements
(3)
The accumulators can be fitted in the hydraulic circuit, directly on a component or in blocks on
suitable consoles.
They should be fitted in as cool a location as possible.
Installation can be in any position.

4-17
(4) Maintenance of the accumulator
No special maintenance beyond the legal requirements is necessary.
The accumulator should be checked annually. It should be replaced if the initial gas pressure has
fallen by more than 30% (please refer to Performance testing and checking of the accumulator).
(5) Disposal of the accumulator
Before the accumulator is scrapped, its gas filling pressure must be reduced. For this purpose,
drill a hole through gas chamber (B) using a drill approx. 3mm in diameter. The gas chamber is
located on the side opposite the threaded port above the welding seam around the center of the
accumulator.
※ Wear safety goggles when doing this job.
(6) Performance testing and checking of the accumulator
The accumulator is gradually pressurized via the test pump; until the initial gas pressure is
reached, the hydraulic pressure in the accumulator will rise abruptly. This is apparent from gauge
M. If the initial gas pressure is more than 30% below the prescribed value, the accumulator needs
to be replaced. If the measuring process needs to be repeated, wait for intervals of 3 minutes
between the individual tests. Any accumulator whose initial gas pressure is insufficient must be
scrapped following the instructions under Disposal of the accumulator
accumulator.
The amount of initial gas pressure can also be checked from the vehicle. Start the vehicle's
engine. The pump will now supply oil to the accumulators. Until the initial gas pressure is
reached, the hydraulic pressure in the accumulator will rise abruptly. This is apparent from the
gauge in the cab. If the initial gas pressure is more than 30% below the prescribed value, that
initial pressure lies outside the permissible range for at least one of the accumulators fitted in the
vehicle. This accumulator can be traced only by using the method described above, i.e. all
accumulators have to be individually tested. The accumulator whose initial gas pressure is
insufficient must be replaced and scrapped following the instruction under Disposal of the
accumulator.
accumulator

Accumulator
Pressure gauge(M)

Ball valve for

shutting off pump flow
Safety valve

Ball valve for

reducing pressure
75794BS10

(7) Repair work

When working on the braking system, always make sure that there is absolutely no
pressure in the system. Even when the engine in switched off there will be some residual
pressure in the system.
※ When doing repair work, make sure your environment is very clean.
Immediately close all open ports on the components and on pipes using plugs.
For safety reasons the accumulators need to be replaced as a whole if damaged.

4-18
7. PRESSURE SENSOR AND SWITCH
1) STRUCTURE

Connector
- Normally closed
300mm

H1
H1

- Normally open

H2

H2
G G
H1
75794BS11

2) TECHNICAL DATA
H1 H2 Adjusting range Actuating pressure Voltage
Item Type Medium G
mm mm kgf/cm2 kgf/cm2 V
Parking
NC Oil PF 1/4" 49.6 11 0 ~ 200 100 ± 5 Max 30
pressure sensor
Charging
NC Oil PF 1/4" 49.6 11 0 ~ 200 100 ± 5 Max 30
pressure sensor
Brake stop
NO Oil PF 1/4" 49.6 11 1 ~ 10 5±1 Max 32
pressure switch
NC : Normally closed NO : Normally open

4-19
2) OPERATION
(1) Purpose
The pressure switches are used to visually or audibly warn the driver of the pressure within the
system.
(2) Make contact / circuit closer
The pressure switch can be fitted in the braking system or directly on one of its components.
The system pressure acts on an absorption area within the switch, making an electrical contact
as the pressure on that area is increased. The resulting current is used to activate a warning
facility, for instance.
(3) Break contact / circuit breaker
The pressure switch can be fitted in the braking system or directly on one of its components.
The system pressure acts on a absorption area within the switch, breaking an electrical contact
as the pressure on that area is increased. The current is now broken, e.g. to deactivate a warning
facility.
(4) Installation requirements
No special measures need to be taken.
(5) Maintenance of the pressure switch
No special maintenance beyond the legal requirements is necessary.
When using high-pressure cleaners on the vehicle, please make sure that the water jet is not
directed at the pressure switch (corrosion of contacts).
(6) Repair work
When working on the braking system, always make sure that there is absolutely no
pressure in the system. Even when the engine is switched off there will be some residual
pressure in the system.
※ When doing repair work, make sure your environment is very clean.
Immediately close all open ports on the components and on pipes using plugs.
※ For safety reasons the pressure switch needs to be replaced as a whole if damaged.

4-20
8. PARKING BRAKE SYSTEM
1) STRUCTURE

2
9

4
8
7
3
6

78094BS21

1 Housing 4 Adjust screw 7 Lining pad

2 Pressure ring 5 Bank of cup springs 8 Lining pad
3 Thrust bolt 6 Piston 9 Gliding bolt

2) OPERATION
The two identical brake pads and slide freely on the guide bolt, which is fastened in the housing.
The guide bolts are guided in an additional brake anchor plate which in turn is screwed onto the
vehicle, i.e. its axle.
On actuation, the brake generates a clamping force at the brake lining pads, which cause a
tangential force/braking moment to be generated at the brake disk, the extent of which depends on
the coefficients of friction generated by the linings.
The clamping force is generated by the bank of cup springs, during which the piston is moved
together with the adjusting screw, the thrust bolt and the brake pad towards the brake disk.
When the brake pad comes into contact with the brake disk, the reaction force shifts the housing
onto the guide bolts until the brake pad is also pressed against the brake disk.
The brake is released by complete pre-tensioning of the bank of cup springs. During this process,
through application of the necessary release pressure after overcoming the cup spring force, the
piston must move back until it comes to rest against the pressure ring.
The clamping force diminishes with wear of the brake lining and brake disk. The brake must be
adjusted at the latest at the times indicated by the adjusting specification followings.

4-21
3) MOUNTING AND BASIC SETTING REGULATIONS
Basic brake setting is required after mounting new brake lining plates or brake disks, as well as
during all repair stages and in the event of insufficient braking performance.

6
2

1
3
4

P
5
S

100D7BS112

1 Thrust bolt 4 Screw cap P Even surface

2 Bank of cup springs 5 Lock nut S Socket wrench
3 Adjusting screw 6 Piston

※ All mounting and basic setting work must be carried out on the brake when cold.

(1) Mounting the brake

① Stand the vehicle on an even surface and secure against rolling away.
② Release the screw cap.
③ Release the lock nut (size 24 or 30) and turn the adjusting screw anticlockwise using a size 8 or
10 socket wrench until the pressure bolt comes to rest against the even surface of the piston. In
this status, the brake can be mounted onto the brake disk and fastened.
④ Mount the pressure connection again.
Apply the necessary release pressure to the brake until the bank of cup springs is completely
pre-tensioned. Following carry out the following page basic setting regulation.

4-22
(2) Basic setting regulation
① Turn the adjusting screw manually clockwise until both brake pads make contact with the brake
disk. Then it is not longer possible to turn the adjusting screw without exerting a major amount
of force.
② Turn the adjusting screw anticlockwise in order to set the following rated clearances.

Adjusting screw Clearance (mm) Turns

Min. 1.0 1/4
M20 (SW 10) Clearance 2.0 1/2
Max. 3.0 3/4

③ Hold the adjusting screw in position with a hexagonal socket wrench and lock with lock nut.
④ Mount the screw cap and tighten as far as possible manually.
⑤
Mount the pressure connection in accordance with the instructions of the axle.
※ For bleeding the piston chamber use the socket spanner size 13 for the bleeding valve.

(3) Adjusting regulations

During this adjusting process, the parking brake must be released, i.e. the bank of cup springs
must be completely pre-tensioned.
① Stand the vehicle on an even surface and secure against rolling away.
② Release the parking brake by using the required release pressure.
③ Release the screw cap and unscrew.
④ Release the lock nut (size 24 or 30) and turn the adjusting screw with socket wrench size 8 or 10
manually clockwise until the two brake pads make contact with the brake disk.
⑤ Turn the adjusting screw anti-clockwise and set the clearance specified in the above table.
⑥ Hold the adjusting screw in position with the hexagonal socket wrench and lock with the lock nut.
⑦ Mount the screw cap and tighten as far as possible manually.
※ Actuate the brake valve several times and check the braking efficiency of the parking brake on a
slope.

4-23
4) EMERGENCY RELEASE OF THE PARKING BRAKE
After the failure of the pressure release the parking brake by using following manual procedure.

2
1
P
S 4
5 3

100D7BS117

1 Thrust bolt 4 Screw cap P Even surface

2 Bank of cup springs 5 Lock nut S Socket wrench
3 Adjusting screw 6 Piston

(1) The vehicle has to be secured against rolling away.

(2) Release the screw cap and unscrew
(3) Release the lock nut (size 24 or 30) and turn the adjusting screw with socket wrench size 8 or 10
manually counter-clockwise until the brake disc is free.
For the emergency release is an actuation torque of 40
40Nm
Nm respectively 70
70Nm
Nm required.
(4) Mount the lock nut and the screw cap and tighten both as far as possible manually. (protection
against dirt)
Now, the vehicle do not have any brake function. The vehicle must be secured against
moving away with proper means. Before putting the vehicle into operation again, the brake
has to be adjusted again. Refer to previous page. "Assembly and basic setting regulations".

4-24
5) MAINTENANCE AND REPAIR WORK
(1) Maintenance and exchange of brake pads
The brake pads themselves are maintenance free. All that is required here is a check for
damaged parts, as well as inspection to ensure that the brake disk remains easy running.
The thickness of the brake lining must be subjected to a visual inspection at regular intervals,
which depend on vehicle usage, but every six months at the latest. In the event of a minimal
residual lining thickness, these intervals must be reduced accordingly in order to avoid major
damage to the brake or disk.
Min. residual thickness 2.0 mm per lining pad (8 mm carrier plate thickness).

1
2

S1 2

4
P
3
S

100D7BS113

1 Piston S Socket wrench

2 Adjusting screw S1 Screwdriver
3 Lock nut P Inside of the piston
4 Thrust bolt

※ Only original spare lining plates may be used. If any other spare parts are used, no warranty
claims will be accepted either for the brakes or their functional characteristics.
① Stand the vehicle on an even surface and secure against rolling away.
② Release the parking brake by applying the required release pressure.
③ Release the screw cap and unscrew.
④ Release the lock nut (size 24 or 30) and turn the adjusting screw with socket wrench size 8 or 10
manually clockwise until it lies flush with the inside of the piston.
⑤ Press back the thrust bolt using a suitable screwdriver until it has contact with the piston.

4-25
 6b

6a
1
4
5
3 2

100D7BS114

1 Guide bolt 5 Castellated nut

2 Lining pad 6a Safety splint
3 Lining pad 6b Safety clip
4 Permanent magnet

⑥ Depending on the free space available, release one of the two guide bolts, removing the safety
splint, unscrewing the castellated nut and pulling the guide bolt out of the brake anchor plate.
Now, the brake lining pads can be removed tangentially to the brake disk.
※ In the event of minimal clearance, i.e. it is not possible for space reasons to exchange the brake
lining plate in accordance with these instructions, the brake must be removed completely. To do
this, pull both guide bolts out of the brake anchor plate.
Check the pressure hose. If the pressure hose is to short, it must be unscrewed to remove
the brake. Before the pressure hose can be released the brake must be emergency
released.
⑦ Exchange the brake pads and insert the guide bolts into the brake anchor plate. If you have
removed the complete brake you have to amount the brake on both guide bolt again, now.
⑧ Check both permanent magnets if they still have sufficient magnetic force to hold the brake lining
plates. Should this not be the case, the permanent magnets must also be changed by using a
suitable screw driver.
⑨ Secure the guide bolt with the castellated nut and the safety splint respective safety clip.

After mounting new brake lining plates or their repair, the brake must be correctly set in
accordance with the instructions "Adjusting regulations".

4-26
(2) Changing the seal

A
B

3
1 2
8
9 4
7
6
5

DETAIL A DETAIL B

100D7BS115

1 Piston 5 Circlip 9 Bank of cup spring

2 Adjusting screw 6 Seal A Detail of the seal
3 Lock nut 7 Guide bolt B Detail of the seal
4 Housing 8 Thrust bolt

※ Faulty seals must be exchanged in accordance with the instructions below.

① Stand the vehicle on an even surface and secure against rolling away.
② Release the parking brake by applying the necessary release pressure.
③ Release the screw cap and unscrew.
④ Release the lock nut (size 24 or 30) and turn the adjusting screw with socket wrench size 8 or 10
manually counter clockwise until the adjuster screw is flush with the inner side of the piston.
⑤ Push back the thrust bolt until it has contact with the piston. Following actuate the hand brake
valve (no pressure must be in the piston chamber). The bank of cup springs is now completely
depressurized.
⑥ Unscrew the pressure hose and remove the brake.
⑦ Release the circlip and remove the pressure ring of the housing.
⑧ Release the bank of cup spings and the piston.
Pay attention to the mounting direction of the seal rings, otherwise leaks can occur.
Use for mounting the new seal rings a suitable mounting needle with rounded edge.
Be careful.

4-27
⑨ Change all seals and mount the parts of the brake in other way round order. By mounting the
piston, the sliding and sealing surfaces must be greased lightly using lubricating grease to DIN
51825. The dust protection cap is fitted with a vulcanized-in steel ring which is used to press it
through the locating hole. For exchanging, "lever out" the ring using a suitable tool. The new
dust protection cap must be pressed in with the aid of a suitable mounting ring and screw
clamps or a lever press.
(2) General
Any discovered defects or damage to parts not listed here must naturally be repaired or replaced
using original parts.
For any other information not contained in these instructions or for more detailed instructions,
please contact Hyundai dealer.

4-28
GROUP 2 OPERATIONAL CHECKS AND TROUBLESHOOTING

1. OPERATIONAL CHECKS
This procedure is designed so the mechanic can make a quick check of the system using a minimum
amount of diagnostic equipment. If you need additional information, read structure and function
function,
Group 1.
A location will be required which is level and has adequate space to complete the checks.
The engine and all other major components must be at operating temperature for some checks.
Locate system check in the left column and read completely, following the sequence from left to right.
Read each check completely before performing.
At the end of each check, if no problem is found (OK), that check is complete or an additional check is
needed. If problem is indicated (NOT OK), you will be given repair required and group location.
If verification is needed, you will be given next best source of information:

Chapter 2 : Troubleshooting


Group 3 : Tests and adjustments

4-29
öHydraulic oil must be at operating temperature for these checks (refer to page 6-56).

Item Description Service action

Parking brake capacity Start engine. OK
check Check completed.
Fasten seat belt.
Seat belt must be worn
NOT OK
while doing this check to Release parking brake and put
Inspect parking brake. Go
prevent possible injury transmission in 2nd gear forward.
to group 3.
when machine stops
Drive machine at 8 km/hr and
suddenly.
switch parking brake ON.
ON LOOK/FEEL : Machine must
Release
come to a stop within 2 meters (6
feet) when parking brake is
P

engaged at 8 km/hr.
Transmission must shift to neutral.
Parking brake Turn parking brake to ON. OK
transmission lockout Check completed.
Place transmission in 1st forward.
check
P

NOT OK
Engine running. Slowly increase engine speed to
Go to transmission control
high idle.
circuit in section 3.
LOOK : Machine must not move.

4-30
 Item Description Service action
Service brake pump flow Stop engine. OK
check Check completed.
Operate brake pedal approximately
ö Hydraulic oil must be at
20 times. NOT OK
operating temperature
Start engine and run at low idle. Check for brake circuit
for the check.
leakage.
Engine OFF. Record number of seconds
required for low brake pressure Go to next page.
indicator lamp to go out.
IF OK
LOOK : Indicator lamp must go out I n s t a l l a c a p o n l i n e
in less than 4 seconds from time connected to inlet of brake
engine starts. valve and repeat pump
flow check.
NOTE : Indicator will not come on
approximately 1 second after If time does not decrease,
starting engine. check for wor n brake
pump.
Service brake capacity Turn clutch cut-off mode switch OK
check OFF. Check completed.
OFF

Engine running.
Apply service brakes, release park NOT OK
L

M H
brake and put transmission in 2nd Check brake pressure.
forward.
IF OK
Increase engine speed to high idle. Inspect brake disk.
LOOK : Machine may not move or
P

move at a very slow speed.

Repeat check three times to ensure
accurate results.

4-31
 Item Description Service action
Brake accumulator S t a r t a n d r u n e n g i n e fo r 3 0 OK
precharge check seconds. Check completed.
öThe axles and hydraulic
Stop engine and turn start switch to NOT OK
oil must be at operating
ON and wait 5 seconds. Make sure brake pedal is
temperature for this
not binding and keeping
check. NOTE : Engine oil pressure lamp
brakes partially engaged.
will be on due to no engine oil
pressure. Bleed brakes in group 3.
Count the number of times the C h e c k b r a k e s y s t e m
brake pedal can be fully depressed pressure.
before the low brake pressure
NOT OK
warning lamp comes ON.
If light comes ON with
LOOK : Warning lamp must come e n g i n e r u n n i n g ,
ON in 1~5 applications. accumulator has lost it's
charge. Inspect and
Start engine and operate at low
recharge accumulator.
idle.
Observe cluster while applying
brake pedal with maximum force.
LOOK/LISTEN : Brake pressure
indicator must not come ON.
Brake system leakage Start engine and wait 30 seconds. OK
check Check completed.
Stop engine.
NOT OK
Wait 2 minutes.
If brake leakage is
Turn start switch to ON and wait 5 indicated with brakes
seconds. released, check leakage at
accumulator inlet check
LOOK : Brake oil pressure warning
valve and brake valve. If
lamp must not come ON within 2
brake leakage is indicated
minutes after stopping engine.
with brakes applied, check
for leakage at brake valve
and brake pistons.
Check individual
component leakage.

4-32
 Item Description Service action
S e r v i c e b ra ke p e d a l Slowly depress brake pedal. OK
check Check completed.
Listen for a hissing noise that
indicates oil is flowing to brake NOT OK
pistons. Inspect for debris under
brake pedal.
LISTEN/FEEL : A hissing noise
must be heard when pedal is
depressed.
Service and parking Position machine on gradual slope. OK
brake system drag Check completed.
Lower bucket approximately 50 mm
checks
(2 in) from ground.
Engine running NOT OK
Release parking and ser vice Adjust park brake.
brakes.
NOT OK
LOOK : Machine must move or
Check floor mat interfer-
coast.
P

ence to pedal or debris

NOTE : If machine does not move, build-up.
check brake pedals to be sure they
fully release when feet are removed IF OK
from pedals. Check for brake pressure
when brake is released.
Drive machine at high speed for
about 5 minutes.
Go to brake pressure test.
Brake drag is indicated if brake
areas in differential case are hot.
NOTE : Observe parking brake.
If disk is hot, parking brake drag is
indicated.
Clutch cut-off check Place clutch cut-off mode switch in OK
L position. Check completed.
Release parking brake. NOT OK
Adjust clutch cut-off switch.
Run engine at half speed in 1st
forward.
Firmly depress brake pedal.
F E E L : Tr a n s m i s s i o n m u s t
disengage when brake pedal is
depressed at 30% of pedal stroke.
OFF

NOTE : Clutch cut-off mode switch

L

M H
can be selected to operator
preference to match your loading
needs.

4-33
2. TROUBLESHOOTING
1) SERVICE BRAKE
Diagnose malfunction charts are arranged from most probable and simplest to verify, to least likely,
more difficult to verify. Remember the following steps when troubleshooting a problem :
Step 1. Operational check out procedure (see section 1)
Step 2. Operational checks (in this group)
Step 3. Troubleshooting
Step 4. Tests and adjustments (see group 3)

Problem Cause Remedy

Poor or no brakes Brake accumulator charge low. Do brake accumulator check.
Brake pump standby pressure Do brake pump standby pressure test.
low.
Brake pressure low. Do brake valve pressure test.
Air in system. Bleed brakes.
Worn brake surface material. Inspect brake surface material.
Leakage in brake valve. Do brake valve leakage test.
Leakage in brake piston seal. Check for an over filled differential.
Apply brakes and check for leakage from check
plug.
öIt is normal for the oil level to be slightly
above the check plug.
Aggressive brakes Internal restriction in circuit. Remove lines and components.
Brake valve malfunction. Disassemble and inspect.
Low oil level. Check oil level.
Brakes drag Brake pedal not retur ning Inspect floor mat and pedal.
properly.
Debris holding valve partially Do brake valve pressure test.
open in brake valve.
Warped brake disk. Inspect brake disk.
Stuck brake piston. Repair.
Brakes lock up Brake valve malfunction. Clean or replace brake valve.

4-34
 Problem Cause Remedy
Brakes chatter Air in brake system. Do brake bleed procedure.
Worn brake surface material. Inspect brake surface material.
Wrong oil in differential. Drain.Refill.
H i s s i n g n o i s e w h e n Leakage in brake valve, or brake Do brake system leakage test.
brake pedal is held with piston.
engine stopped
Brake pressure warning M a l f u n c t i o n i n b r a k e l o w Replace switch.
light will not go out or pressure warning switch.
stays on excessively long
Brake accumulator pressure too Recharge accumulator.
after start-up
low.
L ow b r a ke p u m p s t a n d by Do brake pump standby pressure test.
pressure setting.
Leakage in pressure reducing Do pressure reducing valve manifold leakage
manifold block. test.
Leakage in brake system. Do brake system components leakage tests.
Worn brake pump. Do brake pump flow test.
Leakage in par king brake Do parking brake pressure test.
solenoid.

2) PARKING BRAKE MALFUNCTIONS

Problem Cause Remedy

Brake will not hold Pads not adjusted correctly. Adjust parking brake.
Malfunctioning parking brake Inspect and replace.
solenoid.
Worn brake disk and / or brake Disassemble, inspect, repair.
pads.
Brake piston hangs up in bore. Remove and inspect. Repair.
Brake disk overheats Pads out of adjustment. Adjust parking brake.
Brake not released. Release parking brake.
Disassemble, inspect brake.
Repair if necessary.
Inspect for loosen or broken lines between brake
pressure switch and indicator on dash.
Parking brake indicator in Faulty wiring or switch. Inspect for loose or broken lines between brake
monitor does not come pressure switch and indicator on dash.
on when brake applied Inspect for a faulty indicator on dash. Replace if
necessary.
Brake will not apply Pads out of adjustment. Adjust parking brake.
Malfunctioning wiring, switch, or Check electric circuit.
solenoid.
Restriction between brake valve Remove hose and inspect. Replace.
and brake.

4-35
GROUP 3 TESTS AND ADJUSTMENTS

1. PARKING BRAKE PERFORMANCE

1) MEASUREMENT
EASUREMENT CONDITION
(1) Tire inflation pressure : Specified pressure
(2) Road surface : Flat, dry, paved surface
with 1/5 (11˚20') gradient.
(3) Machine : In operating condition 20%
gradient 11 20'
Item Standard valve
Parking brake Keep machine on 20%
performance (11˚20') gradient 78094BS17

2) MEASURING PROCEDURE
(1) Start the engine and drive the machine
straight up a 1/5 gradient with the bucket
unloaded.
(2) Depress the service brake, place the gear
selector lever in neutral, then stop the
engine.
20%
(3) Turn the parking brake switch ON, then gradient
11 20'
slowly release the service brake pedal
and the machine must be kept stopped.
ö The measurement must be made with
the machine facing either up or down
78094BS18
the slope.

2. ADJUSTMENT OF PARKING BRAKE

(1) External brake inspection
ÂInspect for wear of brake pad

(2) Refer to the PARKING BRAKE SYSTEM

on the page 4-21.

Adjust nut

75794BS22

4-36
3. HYDRAULIC BRAKE BLEEDING PROCEDURE
Escaping fluid under pressure can
penetrate the skin causing serious injury.
Avoid the hazard by relieving pressure
before disconnecting hydraulic or other
lines. Tighten all connections before
applying pressure.
Search for leaks with a piece of cardboard.
Protect hands and body from high Air breather
pressure fluids.
ö If an accident occurs, see a doctor
immediately. Any fluid injected into the skin
must be surgically removed within a few Breather vent
hours or gangrene may result.
Doctors unfamiliar with this type of injury
should reference a knowledgeable medical
source.
Two people are required to bleed brake
system oil, one to operate brake valve and
other to open and close bleed screws.
A
1) Install frame locking bar. Engage parking
brake.
2) Put a clear plastic tube on bleed screw to
route low to hydraulic oil tank filler tube or
container (A).
3) Start engine and run at low idle.
4) Push and hold brake pedal down until
brake bleeding procedure is complete.
ö If bubbles continue for more than 2 Front
frame
minutes, stop bleeding procedure.
Check for and correct problem, then
continue.
Lock bar
lock position
5) Open on bleed screw on differential and
axle assembly until hydraulic oil starts to
flow. Close bleed screw when oil is free of
air. Release brake pedal.
6) Repeat steps 1)~5) for each bleed screw.
7) Push either brake pedal and hold down.
78094BS19
8) Check hydraulic oil level.

4-37
GROUP 4 DISASSEMBLY AND ASSEMBLY

1. BRAKE PUMP
1) STRUCTURE

26

Fan pump
28
25
24
18
5
8

14
11
3 10 16
21
22 13 27
29

20
9
6

19
15
12
2
1

4 Brake pump
7

23 17

78094BS06

1 Body 11 Screw 21 Shaft seal

2 Rear cover 12 Screw 22 Ring
3 Front cover 13 Nut 23 Ring
4 Thrust plate 14 Screw 24 Ring
5 Bushing 15 Washer 25 Sleeve bearing
6 Drive gear 16 Washer 26 Hub
7 Driven gear 17 Seal 27 Dowel pin
8 Drive shaft 18 Seal 28 Steel bushing
9 Driven gear 19 Seal 29 Housing
10 Stud bolt 20 Seal

4-38
2) DISASSEMBLY

26

Fan pump 28
25
18 24
5
8

14
3 11
10 16
21
22 13 27
29

20
9
6

19
15
12
2
1

4 Brake pump
7
2317

78094BS06-1

※ Before disassembling ensure that the unit itself, bench and tools are thoroughly clean.
(1) Lightly mark the rear cover (2), body (1) and housing (29) to ensure reassembly in the correct
position.
(2) Remove the screws (12) and separate the brake pump unit from the fan pump using a soft faced
hammer.
(3) Remove the hub (26).
(4) Remove the seal element (17, 23) and the body seal (20).
(5) Remove the rear cover (2) from the body (1).
(6) Remove the seal element (17, 23) and the body seal (20).
※ Before removing the internal components each bushing (4) must be marked to denote its location
within the body. On the plain area of the bush away from the seal location, lightly mark.
(7) With the unit laying on its side grasp hold of the drive gear (6) and pull it squarely out of the body
(1) bringing the bushing (4) with it.
(8) Remove the driven gear (7) and the remaining bushing (4).

4-39
3) INSPECTION AND REPAIR
(1) Assessment
Each components should be thoroughly cleaned, carefully examined and assessed for suitability
re-use. Below is a guide for inspecting the various components.
(2) Bo
Body
dy
① Inspect the body bore cut-in where both gears wipe into the body.
② The body can only be re-used if the cut-in is bright and polished in appearance and the depth
does not exceed 0.15 mm (0.006").
③ The body should be replaced if the surface is scored, has a matt appearance or shows signs
that the tip of the gears have dug in and torn away the surface material.
④ The body should be inspected to ensure that there is no superficial damage which may
adversely effect performance or sealing. Pay particular attention to the port threads and body
O-ring seal recesses.
(3) Plate and cover
① The inner surfaces should be inspected to ensure that there is no unusual wear or scoring in
the regions where the body O-rings and seals contact, which result in external leakage.
② Check the shaft seal recess for scoring or damage that could result in oil leakage around the
outer diameter of the shaft seal. Replacement shaft seals can be refitted with Loctite hydraulic
sealant to overcome slight damage in this area.
(4) Bushes
① The side faces which abut the gears should be perfectly flat showing no sign of scoring.
Characteristically there are bright polished areas on this surface caused by loading against the
gear side faces, which is often more pronounced on the low pressure side. The bush should be
replaced if there is any general scoring or fine scoring with a matt appearance or tearing of the
surface material. Often there is a witness where the tips of the opposing gears have wiped an
overlap reassembling a half moon shape. There must be no noticeable wear step as it is critical
that the bush side face is completely flat to the gear side face.
② The bearing liners are acceptable providing that they are not scored or show other damage.
The general outside area of the bush should not show any prominent signs of wear.
(5) Gears
① The gear side faces should be examined for bruising or scoring. Often operation on
contaminated fluid shows scoring between the root of the gear and the journal undercut, which
leaves a wear step. If a wear step can be felt, coincidental with the root diameter, by drawing a
sharp pointed tool across the surface from the undercut outwards towards the tip of the gear,
then the gear is unserviceable.
② The gear teeth should then be carefully examined to ensure that there are no signs of bruising or
pitting.
③ The journal bearing surfaces should be completely free from scoring or bruising. The surface
should appear highly polished and smooth to touch.
④ Examine the area where the shaft seal lips run on the drive shaft, this shows up as a polished
ring or rings. If a noticeable groove can be felt or there is scoring the shaft should be replaced.
⑤ Provided the drive shaft is not damaged from the drive-coupling and the gears have not been
harmed as described above, then the gears can be re-used. If, however, the gears are
damaged they must be replaced as a matched pair.
⑥ As a matter of good practice, when pumps have been disassembled, all the seals should be
replaced. It is most important that only the genuine seals are used.

4-40
4) ASSEMBLY

26

Fan pump 28
25
18 24
5
8

14
3 11
10 16
21
22 13 27
29

20
9
6

19
15
12
2
1

4 Brake pump
7
2317

78094BS06-1

※ Ensure that all parts are perfectly clean and lightly lubricate the bushes and gears with hydraulic
oil (ensure body seal recess and end faces remain free from oil). This will assist with their
assembly when they are later fitted into the body.
(1) Refit the bushing (4) into the undowelled end of the body (1) from where they were removed.
(2) Place the rear cover (2) against the body (1) and then stand the assembly on the cover so that
the hollow dowels are uppermost, i.e. the bushing should be at the bottom with the bushings
against the cover.
(3) Fit the drive gear (6) and driven gear (7) back into their original positions in the body (1).
(4) Refit the plate bushing (4) into their original bores.
(5) Fit the new body seal (20).
(6) Fit the new seal element (17, 23) to the bushing.

4-41
 ASSEMBLY

26

Fan pump 28
25
18 24
5
8

14
3 11
10 16
21
22 13 27
29

20
9
6

19
15
12
2
1

4 Brake pump
7
2317

78094BS06-1

(7) Fit the hub (26) to the body (1).

(8) Fit the rear cover (2), taking care not to dislodge the seal (20) and screw (12) the unit together.
·Tightening torque : 4.6 kgf·m (33.2 lbf·ft)
※ Pour a small amount of oil into a port and check that the drive gear can be rotated without undue
force using a smooth jawed hand wrench hooked around the gear or a suitable half coupling
locked against the key.

4-42
5) RUNNING-IN

Pressure gauge

Test unit Variable

Microbic restrictor
filter

Flow
meter
Relief valve

Strainer

Tank

(730TM-3C) 4-48

(1) A unit which has been re-assembled with either new gears, bushes or body, must be carefully
run-in before it is subjected to full working conditions.
(2) Ideally this should be done on a test rig (see figure) where pressure can be gradually applied and
any wipings from the body cut-in arrested by filters.
(3) It is recommended that the unit is run-in at 1500 rpm, initially, at zero pressure for one minute then
in stages with the pressure increased by 500 psi every minute, until maximum rated pressure has
been attained. Frequently check the system temperature, ensuring that it does not exceed the
maximum permissible figure of 80˚C. If the temperature exceeds the system or unit specification
the test must be delayed and operated off-load until acceptable temperatures are obtained.

4-43
2. BRAKE VALVE
1) STRUCTURE

35
34
28

29
30
31
32 27
33
26

14 25

34 24
35 23
11
22
10
9
8 21

7 20

19
6
18
5
4 17
3 16
2 15
1
75794BS07

1 Plug 15 Spacer 27 Boot

2 Retainer 16 Retaining ring 28 Left pedal and base assy
3 O-ring 17 Retainer 29 Sensor
4 Spring 18 Shim 30 Washer
5 Cap screw 19 Spring 31 Cap screw
6 Washer 20 Spring 32 Cover
7 Housing 21 Spring 33 Screw
8 Lower spool 22 Piston 34 Lever assy (option)
9 O-ring 23 Quad ring 35 Right pedal and base assy
10 O-ring 24 O-ring (option)
11 Upper spool 25 Retainer
14 Housing 26 Cup

4-44
2) DISASSEMBLY
※ Housing (7, 14) and spools (8, 11) are
manufactured as matched sets. These
sets (housing & spool) should not be 27
intermixed with other parts.
26
14
(1) Remove boot (27) from retainer (25) and 25
34
piston (22). 35
24
(2) Remove retainer (25), piston (22), springs 11 23
(21, 20, 19), shim (s) (18) and retainer 10
assembly (17) from housing (14). 22
9
8
※ Be aware of the number of shims (s)
being removed from housing. Retaining 21
7
ring (16) and spacer (15) need not be
20
removed from housing. 6
5 19
(3) Carefully remove cup (26), quad ring (23)
4 18
and O-ring (24) from retainer (25). Note
3 17
direction and order of cup and quad ring.
2 16
※ Be careful not to scratch or mar retainer
bore. 1 15

(4) Remove end plug (1), retainer (2) and

spring (4) from housing (7). Remove
O-ring (3) from end plug (1).
(5) Separate housings (7, 14) by removing
cap screws (5) and washer (6). Remove
O-rings (9, 10) from housings (7, 14).
(6) Carefully remove spools (8, 11) from
housings (7, 14).
※ Be careful not to damage spools or
housing bores.
※ Do not intermix spools & housings. Spool
(8) and housing (7) are a matched set as
are spool (11) and housing (14). 75794BS23

4-45
3) ASSEMBLY
※ Lubricate all rubber components from
repair kit with clean type fluid used in the 27
system. 26
14
(1) Clean all par ts thoroughly before 25
34
assembling. 35
24
(2) Lubricate spool (11) with clean system 11 23
fluid and carefully slide into bottom end of 10
22
housing (14) bore. Note direction of spool 9
8
(11).
※ Spool must slide freely into bore. If either 21
7
part is damaged, a new spool / housing 20
assembly may be required. 6
5 19
(3) Install new O-rings (9, 10) in proper
4 18
O-ring pockets on housings (7, 14).
3 17
(4) Reassemble housings (7, 14) using cap 2 16
screws (5) and washers (6). Use locite 1 15
#242 on cap screws (5) and torque
3.04~3.5 kgf·m (22~25 lbf·ft). 75794BS23
※ Make sure housings line up correctly and
that O-rings (9, 10) remain in their
pockets during assembly.
(5) Lubricate spool (8) with clean system fluid and carefully slide into housing (7) bore. Note direction
of spool (8).
※ Spool must slide freely into bore. If either part is damaged, a new spool / housing assembly may
be required.
(6) Install new O-ring (3) on end plug (1).
(7) Install spring (4), retainer (2) and end plug (1) into housing (7). Torque end plug 4.8~5.5 kgf·m
(35~40 lbf·ft).
(8) Carefully install new cap (26), new quad ring (23) and new O-ring (24) on retainer (25). Note
direction and order of cup and quad ring.
※ Be careful not to scratch or mar retainer bore.
(9) Assembly springs (19, 20, 21), shim (s) (18) and retainer assembly (17) in piston (22).
(10) Carefully install retainer (25) over piston (22) and install retainer (25) assembly into housing (14).
Torque retainer 8.3~9.7 kgf·m (60~70 lbf·ft).
(11) Install new boot (27) on retainer (25) and piston (22).
※ After service, the valve must develop the pressure indicated in the specifications. Shim (s) (18)
may be added or removed to obtain the correct pressure setting.
·Brake pressure setting : 80±5 bar (1160±70 psi)

4-46
 SECTION 5 STEERING SYSTEM

Group 1 Structure and Function ---------------------------------------------------------------------------------- 5-1

Group 2 Operational Checks and Troubleshooting ---------------------------------------------------- 5-18
Group 3 Tests and Adjustments ----------------------------------------------------------------------------------- 5-26
Group 4 Disassembly and Assembly -------------------------------------------------------------------------- 5-34
 SECTION 5 STEERING SYSTEM
GROUP 1 STRUCTURE AND FUNCTION

1. OUTLINE
The steering system of this machine consists of a variable displacement piston pump supplying a load
sensing steering system and a closed center loader system.
This system offers faster response from the priority valve of flow amplifier and the pump. Also if offers
advantages in connection with cold start up and improvements in system stability.
The components of the steering system are :
·Steering pump
·Flow amplifier
·Steering unit
·Steering cylinders
The flow amplifier contain a directional valve, an amplification stage, a priority valve, a pilot pressure
relief valve and shock and suction valve.
The steering pump draws hydraulic oil from the hydraulic tank.
Outlet flow from the pump flows to the priority valve of flow amplifier. The priority valve of flow amplifier
preferentially supplies flow, on demand, to the steering unit. When the machine is steered, the steering
unit routes flow to the steering cylinders to articulate the machine.
When the machine is not being steered, or if pump flow is greater than steering flow, the priority valve
supplies flow to the loader system.
That is, output flow from the steering pump enters into the main control valve for the operation of the
attachment.

5-1
 2. HYDRAULIC CIRCUIT
18

LH RH

CL CR
7

L R

EF
T
PP

HP LS HT

12
C2 C1
A2 A1

Down B2 B1 Up

MCV
B
43 B

DR A DR A
L R
10 6
31 31
9 B

X1 X2
8 P T LS
P 15 X3

T
M LS 2 1
PS

11 13
3 Return line

X1 X2
25
35 37 32 PS
S
P
36 26
PS

B1 B2
T
M
P1 1 2 27
T/M
34 M 28
S1 L2 L1 S2 L4 L3 24

Fan & brake pump

78095SE01

1 Steering pump 12 Shuttle valve (option) 28 Strainer

2 Loader pump 13 Pressure sensor 31 Check valve
6 Steering unit 15 Shuttle valve 32 Pressure sensor
7 Flow amplifier 18 Steering cylinder 34 Motor pump (option)
8 Controller (option) 24 Hydraulic tank 35 Check block (option)
9 Joystick (option) 25 Air breather 36 Pressure sensor (option)
10 Proportional valve (option) 26 Return filter 37 Check valve (option)
11 LS compensating valve (option) 27 Bypass valve 43 Stop valve (option)

5-2
 1) NEUTRAL

18

LH RH

CL CR
7

L R

EF
T
PP
D
HP LS HT

MCV

B 43 B

DR A DR A
L R
6 G
31 31

15
X1 X2

P T LS
X3

Return line

X1 X2
25
32 PS
B1 B2 26
1 2 27
T/M
28
S1 L2 L1 S2 L4 L3 24

Fan & brake pump

78095SE02

 The steering wheel is not being operated so control spool (G) does not move.
 The oil from the steering pump enters port HP of the priority valve of flow amplifier and the inlet pres-
sure oil moves the spool (D) to the right.
 Almost all of pump flow goes to the loader system (main control valve) through the EF port and partly
flows into the hydraulic tank (24) through the control spool (G).
This small flow is useful to prevent the thermal shock problem of the steering unit (6).

5-3
 2) LEFT TURN
18

LH RH

CL CR
7

L R

J
P

EF
T
PP
D
HP LS HT

MCV

B 43 B

DR A DR A
L R
6 G
31 31

X1 X2
P T LS
15 X3

Return line

X1 X2
25
32 PS
B1 B2 26
1 2 27
T/M
28
S1 L2 L1 S2 L4 L3 24

Fan & brake pump

78095SE03

 When the steering wheel is turned to the left, the spool (G) within steering unit (6) connected with
steering column shaft is pushed to the right direction.
 The oil discharged from the pump flows into HP port of flow amplifier (7).
 The delivered oil passes through the main orifice of steering unit (6), through the priority valve spool
(D) of flow amplifier (7). The position of priority spool (D) is determined when the pressure difference
between front and rear of main orifice is balanced with control spring (K) force.
 The oil supplied through the directional spool (J) from the steering unit (6) is combined with the direct
oil from the priority valve spool (D) in the amplifier spool (M). The amplified oil flows into the small
chamber of the left steering cylinder and large chamber of the right steering cylinder respectively.
 Oil returned from left and right cylinder returns to hydraulic tank through directional spool (J) of flow
amplifier (7).
 When the above operation is completed, the machine turns to the left.

5-4
 3) RIGHT TURN
18

LH RH

CL CR
7

L R

J
P

EF
T
PP
D K
LS HT

MCV

B 43 B

DR A DR A
L R
6
G
31 31

X1 X2
P T LS
15 X3

Return line

X1 X2
25
32 PS
B1 B2 26
1 2 27
T/M
28
S1 L2 L1 S2 L4 L3 24

Fan & brake pump

78095SE04

 When the steering wheel is turned to the right, the spool (G) within steering unit (6) connected with
steering column shaft is pushed to the right direction.
 The oil discharged from the pump flows into HP port of flow amplifier (7).
 The delivered oil passes through the main orifice of steering unit (6), through the priority valve spool
(D) of flow amplifier (7). The position of priority spool (D) is determined when the pressure difference
between front and rear of main orifice is balanced with control spring (K) force.
 The oil supplied through the directional spool (J) from the steering unit (6) is combined with the direct
oil from the priority valve spool (D) in the amplifier spool (M). The amplified oil flows into the small
chamber of the right steering cylinder and large chamber of the left steering cylinder respectively.
 Oil returned from left and right cylinder returns to hydraulic tank through directional spool (J) of flow
amplifier (7).
 When the above operation is completed, the machine turns to the right.

5-5
3. STEERING PUMP
1) STRUCTURE (1/2)
This steering pump is variable displacement piston pump.

L1 X1 B1
X1

B1

T/M

S1 L2 L1

Hydraulic circuit
L2 S1

78096WE88-1

Port Port name Port size

B1 Pressure port SAE 1 1/4"
S1 Suction port SAE 2 1/2"
L1, L2 Case drain port 1 5/16-12UN
X1 Pilot pressure port 7/16-20UNF

ö Function, disassembly and assembly : Refer to page 6-11~18 and 6-67~80.

5-6
 STRUCTURE (2/2)

27
23

6,31 2

51

33 16
12

1-2

1-1

30

7
17
22

15
20
25

78096WE11

1 Rotary group 8 Drive shaft 23 O-ring

1-1 High speed rotary group 12 Adjustment shim 25 V-ring
1-2 Control plate 15 Taper roller bearing 27 Socket screw
2 Adjusting piece 16 Taper roller bearing 30 Locking screw
5 Pump housing 17 Bearing liner 31 Double break-off pin
6 Port plate 20 Shaft seal ring 33 Cylinder pin
7 Swash plate 22 O-ring 51 Control valve

5-7
4. FLOW AMPLIFIER
1) STRUCTURE

21 7 38 4 9C 21

16
T

HT

2 2
24
28
CR CL
34 34
23
L HP R
1 P 29
9A 1

27 13,14

1 1
8 41
40 35
10

11,12

37
22
P
9B HP EF 30
LS
15 PP 16
2
2
31
42 6 19 20 5 36
(770-7) 5-6

1 O-ring 12 Spring washer 28 Spring

2 O-ring 13 Screw 29 Spring
4 O-ring 14 Spring washer 30 Spring
5 Washer 15 End cover 31 Throttle check valve
6 Washer 16 End cover 34 Orifice
7 O-ring 19 Relief valve 35 Orifice
8 O-ring 20 Plug 36 Orifice
9A Amplifier valve 21 Shock, suction valve 37 Plug
9B Priority valve 22 Spring seat 38 Plug
9C Directional valve 23 Spring seat 40 Spring
10 Check valve 24 Spring guide 41 Spring
11 Screw 27 Orifice 42 Orifice

5-8
2) OPERATION
(1) Introduction
The flow amplifier contain a directional valve, an amplification stage, a priority valve, a pilot pres-
sure relief valve and shock and suction valves.
The flow amplifier amplifies the oil flow from the steering unit cylinder ports L or R by an amplifi-
cation factor of 8. The amplified oil flow is directed from the flow amplifier ports CL or CR to the
steering cylinder. The amplified flow is proportional to the rate of the steering wheel rotation. If
the oil flow from the pump fails, the flow amplifier cuts off the amplification.
(2) Priority valve
(2
The priority valve is used in load sensing systems where the same pump supplies oil to both
steering system and working hydraulics.
The steering system always has first priority.
The pressure on the LS connection is almost zero during measuring (steering unit in neutral posi-
tion).
(3) Shock valves
(3
The shock valves protect the flow amplifier against shock from external forces on the steering cyl-
inders. The shock valves in flow amplifier limit the maximum pressure drop from CL to HT and
from CR to HT.
(4) HP-HT ports characteristic
(4
The pilot pressure relief valve protects the steering unit against excess pressure. The pilot pres-
sure relief valve together with the priority valve limit the maximum steering pressure HP-HT.

5-9
(5) Neutral

9C

T
HT

CR CL

L HP R
P

HP EF LS
PP

42 9B 30

CL CR

L R
L R 9C
Steering unit
P
LS
9A

EF TO MCV
42 T
P T PP
9B 30

HP LS HT

7707A5SE100

5-10
In neutral position, the oil passes from the pump across the integrated priority valve (9B) in the flow
amplifier for discharge through the EF port. With the steering unit in neutral, flow through it is blocked
and all flow through the priority valve (9B) in flow amplifier is directed out the EF port to the loader
control valve.
With the engine off, the priority valve spool (9B) is pushed to the left by the spring (30). The passage
to the EF port is blocked while the passage to the P port is open.
When the machine is first started, all pump flow is routed to the steering unit which blocks the flow.
With the flow blocked, the pressure increases.
Steering inlet pressure is supplied through the dynamic orifice (42) in the spool. This causes the priori-
ty valve spool (9B) to shift to the right against the spring (30) and open the EF port.
As long as the steering unit is in neutral, just enough pressure is maintained at the steering unit to
keep the priority valve spool (9B) shifted to the right.
The operating pressure in the loader system has no effect on the operation of the priority valve (9B) of
flow amplifier. With the loader actuated in relief, the priority valve (9B) will not shift until the machine
is steered.
Flow through the priority valve spool (9B) passes from the P port through the orifice (42) and into the
LS port. It flows through the steering unit LS passage which is routed to return when the steering unit
is in neutral. This provides a warm-up circuit for the steering unit to prevent binding of the steering
unit due to oil temperature extremes.
In neutral position, also the directional valve (9C) is in its center position.
This means that knock and impacts from the cylinder are not transmitted to the steering unit. The flow
amplifier is thus of the non-reaction type.

5-11
(6) Mid-turn

9C

T
HT

CR CL

L HP R
P

S
C

N
A
M

HP EF LS
PP

9B 9A

CL CR

L R
L R 9C
Steering unit
P
LS
9A

EF
T
P T PP
9B

HP LS HT

7707A5SE101

5-12
If the steering wheel is turned to the left, a LS signal is passed to the priority valve (9B). The priority
valve (9B) is reversed so that more oil is passed across the P port to the steering unit for discharge
through the L port of the flow amplifier.
The directional valve (9C) is reversed through the pressure being transmitted across the boring in the
spool whereby the spool is moved the right.
The opening shall allow connection between the pilot flow and the pressure control/amplifier valve
(9A).
The pilot pressure from the orifice in chamber C moves the valve to the left and passage for the pilot
flow therefore is possible out of hole F.
The main flow passes from the priority valve (9B) to the circular channel M. As the amplifier spool is
moved to the left, the passage will now be open across the holes N to the chamber S.
The spool goes to a position so that the pressure in chamber S equals the pressure in chamber C.
The passage is now open for the main flow through the priority valve (9B) across the holes A.
The main flow and pilot flow merge and is passed across the directional valve (9C) to the steering cyl-
inder through CL port.
The return oil passes across the directional valve (9C) to the hydraulic tank.

5-13
(7) Full turm

T
HT

CR CL

L HP R
P

HP EF LS
PP

9B T 30

CL CR

L R
L R 9C
Steering unit
P
LS

EF
TO MCV
T
P T PP
D

HP LS HT

7707A5SE102

5-14
When the machine is steered to a full turn, the frames bottom against the steering stops. To limit
steering system pressure, a relief system is built into the priority valve assembly (9B).
When the frames bottom is stopped, the pressure in the steering cylinders increases. This pressure
is sensed at the LS port. When the pressure in the LS port increases enough to push priority valve
spool (9B) off its seat, oil in the load sensing circuit flows to return through the T port. Load sensing
pressure is limited to the pressure setting of the relief valve.
Pressure to the steering unit (pilot pressure), which is sensed at the left end of the priority valve spool
(9B) in flow amplifier, continues to increase until it can move the spool to the right against the load
sensing pressure plus spring (30) force. At this time, all oil flows out of the EF port to the loader con-
trol valve.
If the loader attachment is being operated while steering, the loader function will slow until the
machine reaches the steering stops. At that time, the loader cycle speed will increase until the
machine is steered again.

5-15
4. STEERING UNIT
1) STRUCTURE

1 7

2 8

3 9

4 10
A A
5
11

6
12

SECTION A - A

7607SE17

1 Bearing 5 Gear wheel 9 Spool

2 Neutral position spring 6 Gear rim 10 Check valve
3 Cross pin 7 Sleeve 11 Distributor plate
4 Housing 8 Cardan shaft 12 End cover

2) OPERATION
The steering unit consists of a rotary valve and a rotary meter.
Via a steering column the steering unit is connected to the steering wheel of the machine.
When the steering wheel is turned, oil is directed from the steering system pump via the rotary
valve (spool and sleeve) and rotary meter (gear wheel set) to the cylinder ports L or R, depending
on the direction of turn. The rotary meter meters the oil flow to the steering cylinder in proportion to
the angular rotation of the steering wheel.
Spool (9) is connected directly to the drive shaft of steering wheel. It is connected to sleeve (7) by
cross pin (3) (not in contact with the spool when the steering wheel is at neutral) and neutral posi-
tion spring (2).
Cardan shaft(8) is meshed at the top with cross pin (3) and forms one unit with sleeve (7).
At the same time, it is meshed with gear rim (5) of the gerotor set by spline.
There are four ports in valve body. They are connected to the pump circuit, tank circuit, and the
head, and left and right steering cylinder. In addition, the pump port and tank port are connected
inside the body by the check valve. Therefore, if there is any failure in the pump of engine, oil can
be sucked in directly from the tank through the check valve.

5-16
5. STEERING CYLINDER
1) STRUCTURE

23 21

9,8 3 10 6,5 7 12,11 22 4 24, 25, 26 1 2 15,14 16 17 13 19 18

28,27 20

78095SE05

1 Tube assembly 11 O-ring 21 Pipe assy

2 Rod assy 12 Back-up ring 22 O-ring
3 Gland 13 Piston 23 Hexagon bolt
4 Du bushing 14 O-ring 24 U-bolt
5 Rod seal 15 Back-up ring 25 Hexagon nut
6 Back-up ring 16 Piston seal 26 Spring washer
7 Buffer ring 17 Wear ring 27 Spherical bearing
8 Dust wiper 18 Piston nut 28 Retaining ring
9 Retaining ring 19 Set screw
10 O-ring 20 Pipe assy

2) OPERATION
This machine use to cross connected cylinder for steering operation.
The steering cylinder use a gland (3) to remove piston and sealed seals. Dust wiper (8) located on
the in side of the rod cover protects cylinder inner parts from dust. The piston (13) is fastened to the
rod (2).
The piston uses a single wear ring (17) with a piston seal (16) to seal between the piston and tube.
The gland seals against the tube with two O-rings. The rod is sealed against the gland with a rod
seal (5).

5-17
GROUP 2 OPERATIONAL CHECKS AND TROUBLESHOOTING

1. OPERATIONAL CHECKS
This procedure is designed so the service man can make a quick check of the steering system using
a minimum amount of diagnostic equipment. If you need additional information, prefer to structure
and function in group 1.
A location will be required which is level and has adequate space to complete the checks.
The engine and all other major components must be at operating temperature for some checks.
Locate system check in the left column and read completely, following this sequence from left to right.
Read each check completely before performing.
At the end of each check, if no problem is found (OK), that check is complete or an additional check
is needed. If problem is indicated (NOT OK), you will be give repair required and group location. If
verification is needed, you will be give next best source of information :

ÂChapter 2 : Troubleshooting


ÂGroup 3 : Tests and adjustments

5-18
öHydraulic oil must be at operating temperature for these checks (refer to page 6-56).
Item Description Service action
Steering unit check Run engine at low idle. OK
Check completed.

A
Turn steering wheel until frames are
at maximum right (A) and then left NOT OK

B
(B) positions. Go to next check.
L O O K : Fra m e s mu s t m ove
smoothly in both directions.
When steering wheel is stopped,
frames must stop.
FEEL : Excessive effort must not be
required to turn steering wheel.
NOTE : It is normal for steering to
drift from stops when steering
wheel is released.
Steering system leakage Turn steering wheel rapidly until OK
check frames are against stop. Check completed.
Heat hydraulic oil to Left Right
Hold approximately 2 kg on steer- NOT OK
operating temperature.
ing wheel. Do steering system leakage
Run engine at high idle.
test in group 3 to isolate the
Count steering wheel revolutions
leakage.
for 1 minute.
Repeat test in opposite direction.
LOOK : Steering wheel should
rotate less than 7 rpm.
NOTE : Use good judgment;
Excessive steering wheel rpm does
not mean steering will be affected.
Priority valve (in flow Park machine on a hard surface. OK
amplifier) low pressure Check completed.
Hold brake pedal down.
check
NOT OK
Run engine at high idle.
Do flow amplifier pressure
Steer machine to the right and left test in group 3.
as far as possible.
LOOK : Machine must turn at least
half way to the right and left stops.
Priority valve (in flow Steer to steering stop and release OK
amplifier) high pressure steering wheel. Check completed.
check
Roll bucket back and hold over NOT OK
relief and observe engine rpm. Priority pressure is set too
Run engine at high idle.
high. Do flow amplifier pres-
Turn steering wheel to steering
sure test in group 3.
stop and hold, observe engine rpm.
LOOK : Steering stall engine rpm
must be higher than hydraulic stall
rpm.

5-19
2. TROUBLESHOOTING
ö Diagnose malfunction charts are arranged from most probable and simplest to verify, to least
likely, more difficult to verify. Remember the following steps when troubleshooting a problem :
Step 1. Operational check out procedure (see group 3 in section 1)
Step 2. Operational checks (in this group)
Step 3. Troubleshooting
Step 4. Tests and adjustments (see group 3)

Problem Cause Remedy

No steering Low oil level. Add recommended oil.
Failed steering pump. Remove and inspect return filter for
metal pump particles.
Failed main pump drive. Do main pump flow test.
Stuck priority valve spool. Remove and inspect priority valve spool.
Broken priority valve spring. Remove and inspect spring.
Relief valve in flow amplifier stuck open. Do relief cartridge leakage test in group 3.
No hydraulic functions Stuck open system relief valve. Replace relief valve.
steering normal Locked safety valve. Unlock safety valve.
Plugged pilot line filter. Inspect and replace.
Failed hydraulic pump. Remove and inspect the pump.
Low secondary pressure of RCV. Check the pressure and replace if nec-
essary.

5-20
 Problem Cause Remedy
Slow or hard steering Too much friction in the mechanical parts of Lubricate bearings and joints of steering
the machine. column or repair if necessary.
Check steering column installation.
Cold oil. Warm the hydraulic oil.
Low priority valve pressure setting. Do priority valve pressure test.
Clean or replace cartridge in flow amplifier.
Worn hydraulic pump. Do hydraulic pump performance check .
Sticking priority valve spool. Remove and inspect.
Broken priority valve spring. Remove and inspect.
C o n s t a n t s t e e r i n g t o Air in system. Check for foamy oil.
maintain straight travel
Leakage in steering system. Do steering system leakage check.
Worn steering unit. Do steering system leakage check.
Do steering unit neutral leakage test in
group 3.
Leaf spring without spring force or broken. Replace leaf springs.
Spring in double shock valve broken. Replace shock valve.
Gear wheel set worn. Replace gear wheel set.
Cylinder seized or piston seals worn. Replace defects parts.
S l o w s t e e r i n g w h e e l Leakage in steering unit gerotor. Do steering system leakage check.
movement will not cause
Worn steering unit gerotor. Do steering leakage check.
any frame movement
Steering wheel can be Leakage in steering system. Do steering system leakage check.
turned with frames
against steering stop
Steering wheel turns with Broken steering column or splined cou- Remove and inspect.
n o r e s i s t a n c e a n d pling.
causes no frame move-
Lack of oil in steering unit. Start engine and check steering operation.
ment
Leakage in steering system. Do steering system leakage test in group 3.

5-21
 Problem Cause Remedy
Erratic steering Air in oil. Check for foamy oil.
Low oil level. Add recommended oil.
Sticking priority valve spool. Remove and inspect spool.
Loose cylinder piston. Remove rod to inspect piston.
Damaged steering unit. Remove and inspect.
Spongy or soft steering Air in oil. Check for foamy oil.
Low oil level. Add recommended oil.
Free play at steer ing Loose steering wheel nut. Tighten.
wheel
Worn or damaged splines on steering col- Inspect.
umn or unit.
Steering unit binding or Binding in steering column or misalignment Inspect.
steering wheel does not of column.
immediately retur n to
High return pressure. Check for a pinched or damaged return
neutral when released
line.
Contamination in steering unit. Inspect hydraulic filter for contamination.
Repair cause of contamination. Flush
hydraulic system.
Large particles of contamination in steering Inspect hydraulic filter for contamination.
unit. Repair cause of contamination. Flush
hydraulic system.
Steering unit locks up ★ Thermal shock Do priority valve LS port flow test in group
5. This oil flow provides a warm -up flow to
steering unit when not using the steering.
Worn or damaged steering unit. Repair or replace steering unit.
Abrupt steering wheel Improperly timed gerotor gear in steering Time gerotor gear.
oscillation unit.
Steering wheel turns by Lines connected to wrong port. Reconnect lines.
itself
Vibration in steering sys- High priority valve setting. Do priority valve pressure test.
tem or hoses jump
Neutral position of steer- Steering column and steering unit out of Align the steering column with steering unit.
ing wheel cannot be line.
obtained, i.e. there is a
Too little or no play between steering col- Adjust the play and, if necessary, shorten
tendency towards
umn and steering unit input shaft. the splines journal.
"motoring"
Pinching between inner and outer spools. Contact the nearest service shop.
★ Thermal shock is caused by a large temperature differential(Approx. 30˚C, 50˚F) between the steering
valve and hydraulic oil. If the steering is not operated for a long period of time and the orifice in the bottom
of the priority valve spool is plugged, the steering valve may bind up when the steering is operated if the
hydraulic oil is hot enough.

5-22
 Problem Cause Remedy
"Motoring" effect. Leaf springs are stuck or broken and have Replace leaf springs.
The steering wheel can therefore reduced spring force.
turn on its own.
Inner and outer spools pinch, possibly due Clean steering unit or contact the nearest
to dirt. service shop.
Return pressure in connection with the Reduce return pressure.
reaction between differential cylinder and
steering unit too high.
Oil is needed in the tank. Fill with clean oil and bleed the system.
Steering cylinder worn. Replace or repair cylinder.
Gear wheel set worn. Replace gear wheel set.
Spacer across cardan shaft forgotten. Install spacer.

5-23
 Problem Cause Remedy
Backlash Cardan shaft fork worn or broken. Replace cardan shaft.
Leaf springs without spring force or broken. Replace leaf springs.
Worn splines on the steering column. Replace steering column.
"Shimmy" effect. The Air in the steering cylinder. Bleed cylinder.
steered wheels vibrate. Find and remove the reason for air collec-
(Rough tread on tires tion.
gives vibrations)
Mechanical connections or wheel bearings Replace worn parts.
worn.
High priority valve setting pressure. Set pressure as regular value.
Steering wheel can be One or both shock valves are leaky or are Clean or replace defective of missing
turned slowly in one or missing in steering valve. valves.
both directions without
the steered wheels turn-
ing.
Steering is too slow and Insufficient oil supply to steering unit, pump Replace pump or increase number of revo-
heavy when trying to turn defective or number of revolutions too low. lutions.
quickly.
Relief valve setting too low. Adjust valve to correct setting.
Relief valve sticking owing to dirt. Clean the valve.
Spool in priority valve sticking owing to dirt. Clean the valve, check that spool moves
easily without spring.
Too weak spring in priority valve. Replace spring by a stronger.
"Kick back" in steering Fault in the system. Contact authorized man or shop.
wheel from system. Kicks
from wheels.

5-24
 Problem Cause Remedy
Heavy kick-back in steer- Wrong setting of cardan shaft and gear- Correct setting as shown in this manual.
ing wheel in both direc- wheel set.
tions.
urning the steering wheel Hydraulic hoses for the steering cylinders Connect lines to correct ports.
activates the steered have been switched around.
wheels opposite.
Hard point when starting Spring force in priority valve too weak. Replace spring by a stronger.
to turn the steering wheel
Oil is too thick (cold). Let motor run until oil is warm.
Too little steering force Pump pressure too low. Correct pump pressure.
(possibly to one side
Too little steering cylinder. Fit a larger cylinder.
only).
Piston rod area of the differential cylinder Fit cylinder with thinner piston rod or 2 dif-
too large compared with piston diameter. ferential cylinders.
Leakage at either input Shaft defective. Replace shaft seal.
shaft, end cover, gear-
Screws loose. Tighten screws.
wheel set, housing or top
part. Washers or O-rings defective. Replace.

5-25
GROUP 3 TESTS AND ADJUSTMENTS

1. HYDRAULIC OIL CLEAN UP PROCEDURE USING PORTABLE FILTER CADDY

ö Service equipment and tool.
ÂPortable filter caddy
ÂTwo 3658 mm (12 ft) Ý 1" I.D. 100R1
hoses with 3/4 M NPT ends
ÂQuick disconnect fittings
ÂDischarge wand
ÂVarious size fittings and hoses
ö Brake system uses oil from hydraulic oil
tank. Flush all lines in the steering sys-
tem.
Disassemble and clean major compon-
ents for steering system.
Steering components may fail if steering
system is not cleaned after hydraulic oil
tank contamination.
1) If hydraulic system is contaminated due to
a major component failure, remove and dis-
assemble steering cylinders to clean debris
from cylinders.
2) Install a new return filter element. Clean fil-
ter housing before installing new element.
ö For a failure that creates a lot of debris,
remove access cover from hydraulic oil
tank. Drain and clean hydraulic oil tank of
fill the specified oil to hydraulic oil tank
through upper cover.
3) To minimize oil loss, pull a vacuum in
hydraulic oil tank using a vacuum pump.
Connect filter caddy suction line to drain
port at bottom of hydraulic oil tank using
connector. Check to be sure debris has not
closed drain port.
4) Put filter caddy discharge line into hydraulic
oil tank filter hole so end is as far away from
drain port as possible to obtain a through
cleaning of oil.

5-26
5) Start the filter caddy. Check to be sure oil
is flowing through the filters.
Operate filter caddy approximately 10 min-
utes so oil in hydraulic oil tank is circulated
through filter a minimum of four times.
ö Hydraulic oil tank capacity 234˶(61.8U.S.
gal).
Leave filter caddy operating for the next
steps.
6) Start the engine and run it at high idle.
ö For the most effective results, cleaning pro-
cedure must start with the smallest capacity
circuit then proceed to the next largest
capacity circuit.
7) Operate all functions, one at a time, through
a complete cycle in the following order:
clam, steering, bucket, and boom. Also
include all auxiliary hydraulic functions.
Repeat procedure until the total system
capacity has circulated through filter caddy
seven times, approximately 30 minutes.
Each function must go through a minimum
of three complete cycles for a through
cleaning for oil.
ö Filtering time for machines with auxiliary
hydraulic functions must be increased
because system capacity is larger.
8) Stop the engine. Remove the filter caddy.
9) Install a new return filter element.
10) Check oil level in hydraulic oil tank ; Add oil
if necessary.

5-27
2. TEST TOOLS
1) CLAMP-ON ELECTRONIC TACHOMET-
ER INSTALLATION
 Service equipment and tools
Tachometer
A : Clamp on tachometer.
Remove paint using emery cloth and B
connect to a straight section of injec- D
tion line within 100 mm (4in) of pump. C
Finger tighten only-do not over tighten.
B : Black clip (-). Connect to main frame.
C : Red clip (+). Connect to transducer. A
D : Tachometer readout. Install cable.
(770-3ATM) 5-30

2) DIGITAL THERMOMETER INSTALLATION

 Service equipment and tools
Digital thermometer
A : Temperature probe. A
Fasten to a bare metal line using a
tie band. Wrap with shop towel. B
B : Cable. C
C : Digital thermometer.

(770-3ATM) 5-30

3) DISPLAY MONITOR TACHOMETER

The display monitor tachometer is accurate
enough for test work.

mph

7807A3CD03

5-28
3. STEERING SYSTEM RESTRICTION TEST
 SPECIFICATION
Oil temperature 45Ü5˚C (113Ü9˚F)
Engine speed High idle
Maximum pressure 2.1MPa (21 bar, 300psi)
at flow amplifier
 GAUGE AND TOOL
Gauge 0~7 MPa (0~70 bar, 0~1000 psi) 2EA
 This test will check for restrictions in the Steering pump
steering system which can cause overheat-
ing of hydraulic oil.
1) Install temperature reader.
(see temperature reader installation proce- HP EF

dure in this group).

2) Heat hydraulic oil to specifications.
(see hydraulic oil warm up procedure at
page 6-56). Fitting

3) Connect fitting and install gauge.

Do not operate steering or loader funct-
ions or test gauge may be damaged.
4) Run engine at specification and read pres-
sure gauges.
If pressure is more than specification at the
flow amplifier, inspect flow amplifier for a
priority valve spool. Make sure orifice
plugs installed in ends of priority valve spool. 78095SE18

Check for plugged orifice in flow amplifier LS

port.

5-29
4. STEERING UNIT LEAKAGE TEST
 SPECIFICATION
Oil temperature 45Ü5˚C (113Ü9˚F)
Engine speed High idle
Maximum leakage 7.5˶/min (2 gpm) Cap fitting
 GAUGE AND TOOL
Temperature reader T
L
R
Measuring container (approx. 20˶)
Stop watch
1) Install frame locking bar to prevent machine
from turning.
2) Install temperature reader.
(see temperature reader installation proce-
dure in this group).
3) Heat hydraulic oil to specifications.
(see hydraulic oil warm up procedure at
page 6-56).
4) Disconnect return hose from fitting.
Install cap fitting.
5) Run engine at specifications. Rotate
steering wheel against locking bar using
approximately 1.2 kgfÂm of force. Front
frame
Measure oil flow from return hose for 1
minute.
6) Leakage is greater than specifications, Lock bar
lock position
repair or replace steering unit.

78095SE11

5-30
5. FLOW AMPLIFIER PRESSURE TEST
 SPECIFICATION
Oil temperature 45Ü5˚C (113Ü9˚F)
Engine speed High idle
Oil pressure 20.1~21.1 MPa
(205~215 bar, 2900~3100 psi) Relief valve

 GAUGE AND TOOL

Gauge 0~35 MPa (0~350 bar, 0~5000 psi) CR

Temperature reader CL

1) Connect gauge to test port.

2) Install temperature reader (see installation
procedure in this group). Test port
3) Install frame locking bar.
4) Heat hydraulic oil to specifications (see
hydraulic oil warm up procedure at page
6-57).
5) Run engine at specifications and turn
steering wheel rapidly hold approximately
22N (5lb force) pressure on wheel with
frames locked.
ö If steering wheel is turned slowly, it will
continue to with the frames locked.
This will give an incorrect pressure read-
ing. Front
frame
If steering wheel continues to turn rapidly
with the frames locked, steering system
leakage is indicated.
Lock bar
lock position
6) Read pressure gauge. This is the flow
amplifier relief pressure.
7) If pressure in not to specification, turn
adjusting screw in relief cartridge using a
hex head wrench to adjust pressure.
If pressure cannot be adjusted to specifica-
tion, disassemble and inspect flow amplifier. 78095SE07

5-31
6. FLOW AMPLIFIER LS PORT FLOW TEST
· SPECIFICATION
Oil temperature 45±5˚C (113±9˚F)
Engine speed Low idle
LS port flow (approx.) 1 mℓ/min
· GAUGE
GAUGE AND TOOL
Temperature reader
Measuring container
Stop watch

Flow amplifier LS port flow test will check

for a plugged or missing orifice in the bot- B
EF LS
tom of the priority valve spool. A plugged HP
orifice will block warm up flow to the steer-
ing unit which can cause thermal shock PP
(see for an explanation of thermal shock
A
page 5-22).
A missing orifice can cause the pump to be
loaded to high pressure at all times causing
overheating.
1) Install temperature reader (see temperature
reader installation procedure in this group.)
2) Heat hydraulic oil to specifications (see
hydraulic oil warm up procedure at page
6-56).
3) Disconnect line from LS port and install
plug (A).
4) Connect line (B) to flow amplifier.
5) Start engine and run at specification.
6) Measure flow from LS port for 1 minute.
7) If flow is low, low steering system neutral
pressure or a plugged orifice in bottom pri-
ority valve spool is indicated.
If flow is high, remove priority valve spool
and inspect for a missing orifice.
Do hydraulic system restriction test in this
group. 7707SE19

5-32
7. FLOW AMPLIFIER RELIEF CARTRIDGE
LEAKAGE TEST
 SPEC
SPECIFICATION
IFICATION
Oil temperature 45±5˚C (113±9˚F)
Engine speed High idle
Maximum leakage 1 m˶/min (16 drops per
min) A

 GAUGE AND TOOL

Temperature reader HT
Measuring container T
Stop watch
B
1) Install temperature reader.
(see temperature reader installation proce-
dure in this group).
2) Heat hydraulic oil to specifications.
C
(see hydraulic oil warm up procedure at
page 6-56).
3) Install plug (A) in HT port.
Disconnect line from T port on flow amplifi-
er. Install plug (B) in line.
4) Connect line (C) to flow amplifier.
5) Start engine and run at specification.
6) Measure oil leakage from T port.
7) If leakage is more than specification, disas-
semble and inspect cartridge for damage
or debris. 77095SE20

5-33
GROUP 4 DISASSEMBLY AND ASSEMBLY

1. FLOW AMPLIFIER
1) STRUCTURE
20
5

19
38
4
6

9 A

36
21

7 25
2
26

16 23
27 31
14 29
13 21 28
24
3 34
1 41 7
12
11 9C
35 15 11
2 12
34
24
28
9A 29
23
8 22

13
14
30
10
40 1
9B

42
A 37 7707ASE09

1 O-ring 12 Spring washer 28 Spring

2 O-ring 13 Screw 29 Spring
3 O-ring 14 Spring washer 30 Spring
4 O-ring 15 End cover 31 Throttle check valve
5 Washer 16 End cover 34 Orifice
6 Washer 19 Relief valve 35 Orifice
7 O-ring 20 Plug 36 Orifice
8 O-ring 21 Shock, suction valve 37 Plug
9 Housing 22 Spring seat 38 Plug
9A Amplifier valve 23 Spring seat 40 Spring
9B Priority valve 24 Spring guide 41 Spring
9C Directional valve 26 Name plate 42 Orifice
10 Check valve 27 Orifice
11 Screw

5-34
2) TOOLS
· Guide screws : M8×1.0
· Hook : Wire

(770-3ATM) FA001

· Hexagon keys : 4, 5, 6, 8 and 10 mm

· Ratchet for socket spanners
· Hex socket for external : 13, 17 & 19 mm
· Hex socket for internal : 8 & 10 mm
· Multigrip pliers
· Ring spanner : 13 mm
· Screwdrivers : 3 and 10 mm
· Steel Mandrels : 3, 5 and 8 mm
· Torque wrench : 12.2 kgf·m (88 lbf·ft)
(770-3ATM) FA002
· Magnetic rod

3) DISASSEMBLY
(1) Disassembly counter pressure valve
① Unscrew plug with O-ring (hexagon
socket for 8 mm internal hexagon).

(770-3ATM) FA003

② Take out small spring (hook).

(770-3ATM) FA004

5-35
③ Take out ball (magnetic rod).

(770-3ATM) FA005

④ Take out piston.

(770-3ATM) FA006

⑤ Take out spring.

(770-3ATM) FA007

⑥ Counter pressure valve shown

disassembled.

(770-3ATM) FA008

5-36
 ⑦ Counter pressure valve with orifice
shown disassembled.

(770-3ATM) FA009

(2) Removing pressure relief valve

① Unscrew plug with washer (hexagon
socket for 8 mm internal hexagon).

(770-3ATM) FA010

② Screw pressure relief valve out (10 mm

hexagon key).

(770-3ATM) FA011

③ Take out washer (magnetic rod).

(770-3ATM) FA012

5-37
(3) Disassembly pressure relief valve
① Hold cartridge (multigrip pliers) and
screw the adjustment screw out (5 mm
hexagon key).

(770-3ATM) FA013

② Pressure relief valve shown disassembl-

ed.

(770-3ATM) FA014

(4) Removing end cover at PP-connection

① Unscrew screws with spring washer
using hexagon socket for 13 mm external
hexagon and 10 mm internal hexagon.

(770-3ATM) FA015

② Remove end cover.

(770-3ATM) FA016

5-38
③ Remove stop and 2 springs.

(770-3ATM) FA017

④ Remove spring.

(770-3ATM) FA018

③ Remove plate and 6 O-rings.

(770-3ATM) FA019

④ Remove spring guide.

(770-3ATM) FA020

5-39
(5) Removing end cover at LS-connection
① Unscrew screws with spring washer
using hexagon socket for 13 mm external
hexagon and 10 mm internal hexagon.

(770-3ATM) FA021

② Remove end cover.

(770-3ATM) FA022

③ Remove stop and 2 springs.

(770-3ATM) FA023

④ Remove stop and spring.

(770-3ATM) FA024

5-40
⑤ Remove plate and 4 O-rings.

(770-3ATM) FA025

⑥ Remove spring guide.

(770-3ATM) FA026

(6) Removing spools

① Remove directional spool.

(770-3ATM) FA027

② Remove amplifier spool.

(770-3ATM) FA028

5-41
③ Remove priority valve spool.

(770-3ATM) FA029

(7) Removing orifices and throttle check

valve
① Unscrew orifice in LS-connection with
6 mm hexagon key.

(770-3ATM) FA030

② U n s c r ew t h r o t t l e c h e ck va l ve i n
PP-connection with 6mm hexagon key.

(770-3ATM) FA031

③ Unscrew orifice in housing with 4 mm

hexagon key.

(770-3ATM) FA032

5-42
(8) Removing shock valves
① Remove shock valve with screwdriver
and hexagon key.

(770-3ATM) FA033

(9) Overview of disassembled parts

① Housing and end cover with accessories.

(770-3ATM) FA034

② Spool with accessories.

(770-3ATM) FA035

(10) Disassembly of directional spool

① Unscrew orifice with 4mm hexagon key.
Use a mandrel.

(770-3ATM) FA036

5-43
 ② Directional spool shown disassembled.

(770-3ATM) FA037

(11) Disassembly of priority valve spool

① Unscrew plug or throttle check valve with
8 mm hexagon key.

(770-3ATM) FA038

② Priority valve spool with plug for external

PP shown disassembled.

(770-3ATM) FA039

③ Priority valve spool with throttle check

valve for internal PP shown disassembled.

(770-3ATM) FA040

5-44
(12) Disassembly of amplifier spool
① Carefully remove the spring ring from the
recess with 3mm screwdriver.
※ Avoid damage to the spring ring.

(770-3ATM) FA041

② Carefully guide the spring ring back.

(770-3ATM) FA042

③ Carefully take the spring ring from the

recess and guide it back with 3mm
screwdriver.
※ Avoid damage to the spring ring.

(770-3ATM) FA043

④ Press pin out gently with finger.

(770-3ATM) FA044

5-45
⑤ Take out plug.

(770-3ATM) FA045

⑥ Take out spring.

(770-3ATM) FA046

⑦ Take out pin 3mm screwdriver.

(770-3ATM) FA047

⑧ Take out inner spool.

(770-3ATM) FA048

5-46
 ⑨ Unscrew check valve with hexagon
socket for 17 mm external hexagon and
mandrel in the pin hole.
※ Avoid damaging the spool surface.

(770-3ATM) FA049

⑩ Unscrew orifice out of plug with 4 mm

hexagon key. Use a mandrel.

(770-3ATM) FA050

⑪ Amplifier spool shown disassembled.

(770-3ATM) FA051

(13) Disassembly of check valve

① Unscrew plug with 4 mm hexagon key
and hexagon socket for 17 mm external
hexagon.

(770-3ATM) FA052

5-47
 ② Check valve shown disassembled.

(770-3ATM) FA053

(14) Disassembly of shock valve / suction

valve
① Unscrew locknut with hexagon socket for
13 mm exter nal hexagon. Use a
mandrel.
※ When readjusting shock valve hold
locknut with 13 mm ring spanner.

(770-3ATM) FA054

② Take out disc and spring.

(770-3ATM) FA055

③ Take off housing.

(770-3ATM) FA056

5-48
④ Unscrew pilot valve with hexagon socket
for 19 mm external hexagon. Use a
mandrel.

(770-3ATM) FA057

⑤ Take out pilot valve and spring.

(770-3ATM) FA058

⑥ Take out spool.

(770-3ATM) FA059

⑦ Unscrew adjustment screw and take out

spring and ball.

(770-3ATM) FA060

5-49
⑧ Shock valve / suction valve shown
disassembled.

(770-3ATM) FA061

※ Cleaning
Clean all parts carefully with low aromatic
kerosene.
※ Inspection and replacement
Replace all gaskets and sealing washers.
Check all other parts carefully and
replace if necessary.
※ Lubrication
Before assembly, lubricate all parts with
hydraulic oil.

5-50
4) ASSEMBLY
(1) Assembly of shock valve / suction
valve
① Guide spring with cone into housing.

(770-3ATM) FA062

② Fit adjustment screw.

(770-3ATM) FA063

③ Fit spool.

(770-3ATM) FA064

④ Fit spring.

(770-3ATM) FA065

5-51
⑤ Fit pilot valve.
Remember O-ring.

(770-3ATM) FA066

⑥ Tighten with torque wrench for 19 mm

external hexagon. Use a mandrel.
·Tightening torque : 2±0.5 kgf·m
(14.5±3.6 lbf·ft)

(770-3ATM) FA067

⑦ Fit housing.

(770-3ATM) FA068

⑧ Fit spring.

(770-3ATM) FA069

5-52
 ⑨ Fit disc.

(770-3ATM) FA070

⑩ Fit locknut.
·Tightening torque : 1.5±0.2 kgf·m
(10.8±1.4 lbf·ft)

(770-3ATM) FA071

(2) Assembly of check valve

① Fit ball, spring and plug.
·Tightening torque : 0.5±0.1 kgf·m
(3.6±0.7 lbf·ft)

(770-3ATM) FA072

(3) Assembly of amplifier spool

① Fit orifice in plug.
·Tightening torque : 0.5±0.1 kgf·m
(3.6±0.7 lbf·ft)

(770-3ATM) FA073

5-53
② Fit check valve.
·Tightening torque : 2±0.3 kgf·m
(14.5±2.2lbf·ft)
※ Avoid damaging spool surface.
Remember O-ring.

(770-3ATM) FA074

③ Place inner spool in the correct position.

(770-3ATM) FA075

④ Guide inner spool in.

(770-3ATM) FA076

⑤ Fit pin.

(770-3ATM) FA077

5-54
⑥ Push spring ring into position. Place
spring ring into the recess with ends
facing away from pin holes.

(770-3ATM) FA078

⑦ Fit spring.

(770-3ATM) FA079

⑧ Fit plug.

(770-3ATM) FA080

⑨ Fit pin.

(770-3ATM) FA081

5-55
 ⑩ Push spring ring into position. Place
spring ring into the recess with ends
facing away from pin holes.

(770-3ATM) FA082

(4) Assembly of priority valve spool

① Fit plug or throttle check valve.
External PP : Plug.
Internal PP : Throttle check valve.
·Tightening torque : 1±0.3 kgf·m
(7.2±2.2 lbf·ft)

(770-3ATM) FA083

(5) Assembly of directional spool

① Screw in orifice.
·Tightening torque : 0.5±0.1 kgf·m
(3.6±0.7 lbf·ft)

(770-3ATM) FA084

(6) Installation of orifice and throttle check

valve
① Fit orifice in housing.
·Tightening torque : 0.5±0.1 kgf·m
(3.6±0.7 lbf·ft)

(770-3ATM) FA085

5-56
 ② Fit orifice in LS - connection.
·Tightening torque : 1±0.3 kgf·m
(7.2±2.2 lbf·ft)

(770-3ATM) FA086

③ F i t t h r o t t l e c h e ck va l ve i n P P -
connection.
·Tightening torque : 1±0.3 kgf·m
(7.2±2.2 lbf·ft)

(770-3ATM) FA087

※ Comments on flow amplifiers with internal PP :

1. 1/4 BSP. F in PP - connection.
Fit washer and plug.
·Tightening torque : 4.1±0.3 kgf·m
(29.7±2.2 lbf·ft)
2. 7/16 - 20 UNF in PP - connection.
Fit O-ring and plug.
·Tightening torque : 1.5±0.5 kgf·m
(10.8±3.6 lbf·ft)

(7) Installation of shock valves

① Guide shock valve in and secure it by
hand.
Remember O-ring.

(770-3ATM) FA088

5-57
(8) Assembly of pressure relief valve
① Guide adjustment screw, spring and
cone up into the cartridge.

(770-3ATM) FA089

② Screw the adjustment screw so far in that

the 10 mm hexagon key fully engages.

(770-3ATM) FA090

(9) Installation of pressure relief valve

① Let the washer drop into the hole.

(770-3ATM) FA091

② Fit pressure relief valve.

·Tightening torque : 3.1±0.3 kgf·m
(22.4±2.2 lbf·ft)

(770-3ATM) FA092

5-58
 ③ Fit plug with washer.
·Tightening torque : 6±0.5 kgf·m
(44.1±3.6 lbf·ft)

(770-3ATM) FA093

(10) Installation of back pressure valve

① First fit spring in piston with vaseline.
Fit assembled piston and spring.

(770-3ATM) FA094

② Let the ball drop down.

(770-3ATM) FA095

③ Fit spring in plug with vaseline.

Fit assembled plug and spring.
Remember O-ring.
·Tightening torque : 2.6±0.3 kgf·m
(18.8±2.2 lbf·ft)

(770-3ATM) FA096

5-59
(11) Installation of spools
① Fit directional spool.
Fit priority valve spool.
※ Spring control must be placed in correct
position against LS - connection.

(770-3ATM) FA097

② Fit spring.
※ Spring must be by the LS - connection.

(770-3ATM) FA098

③ Fit amplifier spool.

※ The orifice must be placed in correct
position against LS - connection.

(770-3ATM) FA099

(12) I n s t a l l a t i o n o f e n d c ove r a t P P -
connection
① Fit spring with vaseline on amplifier
※ spool.
The spring must be fitted at the PP -
connection.

(770-3ATM) FA100

5-60
② Fit spring guide with vaseline.

(770-3ATM) FA101

③ Fit large and small springs with vaseline.

(770-3ATM) FA102

④ Fit guide screws.

(770-3ATM) FA103

⑤ Fit 4 large and 2 small O-rings.

(770-3ATM) FA104

5-61
⑥ Guide plate in.

(770-3ATM) FA105

⑦ Fit stop (thickness : 5 mm) in end cover

with vaseline.

(770-3ATM) FA106

⑧ Guide end cover in.

(770-3ATM) FA107

⑨ Fit screw with spring washer.

(770-3ATM) FA108

5-62
 ⑩ Fit screws with spring washer.
·Tightening torque : 2.6±0.5 kgf·m
(18.8±3.6 lbf·ft)
·Tightening torque : 8.2±1 kgf·m
for large screw (59.3±7.2 lbf·ft)

(770-3ATM) FA109

(13) I n s t a l l a t i o n o f e n d c ove r a t L S -
connection
① Fit guide screws.
Fit remote control with vaseline.

(770-3ATM) FA110

② Fit large and small springs with vaseline.

(770-3ATM) FA111

③ Guide in plate with 4 O-rings.

(770-3ATM) FA112

5-63
④ Fit stop for priority valve spool (thickness
: 8 mm) with vaseline.

(770-3ATM) FA113

⑤ Fit stop for directional spool (thickness :

5 mm) with vaseline.

(770-3ATM) FA114

⑥ Guide in end cover.

(770-3ATM) FA115

⑦ Fit large screw with spring washer.

(770-3ATM) FA116

5-64
⑧ Fit screws with spring washers.
·Tightening torque : 2.6±0.5 kgf·m
(18.8±3.6 lbf·ft)
·Tightening torque : 8.2±1 kgf·m
for large screw (59.3±7.2 lbf·ft)

(770-3ATM) FA117

⑨ Fit plastic plugs.

(770-3ATM) FA118

This completes assembly.

5-65
2. STEERING UNIT
1) STRUCTURE

7707SE21

1 Dust seal ring 9 Cross pin 17 End cover

2 Housing, Spool, sleeve 11 Shaft 18 Washer
3 Ball 12 Spring set 20 Pin screw
4 Bushing 13 O-ring 21 Screw
5 Lip seal 14 Distributor plate 32 Check valve
7 Bearing assy 15 Gearwheel set
8 Ring 16 O-ring

5-66
2) TOOLS
(1) Holding tool.

(770-3ATM) 5-69(1)

(2) Assembly tool for O-ring and kin-ring.

(770-3ATM) 5-69(2)

(3) Assembly tool for lip seal.

(770-3ATM) 5-69(3)

(4) Assembly tool for cardan shaft.

(770-3ATM) 5-69(4)

5-67
(5) Assembly tool for dust seal.

(770-3ATM) 5-70(1)

(6) Torque wrench 0~7.1 kgf·m

(0~54.4 lbf·ft)
13 mm socket spanner
6, 8 mm and 12 mm hexagon sockets
12 mm screwdriver
2 mm screwdriver
13 mm ring spanner
6, 8 and 12 mm hexagon socket spanners
Plastic hammer
(770-3ATM) 5-70(2)
Tweezers

5-68
3) TIGHTENING TORQUE AND HYDRAULIC CONNECTIONS
(1) Hydraulic connections

L: Left port
R: Right port
T: Tank
TLPR P: Pump

(770-3ATM) 5-71

(2) Tightening torque

Max. tightening torque [ kgf·m (lbf·ft) ]
Screwed
connection With cutting With copper With aluminum With O - ring
edge washer washer
1/4 BSP.F 4.1 (29.7) 2.0 (14.5) 3.1 (22.4) -
3/8 BSP.F 6.1 (44.1) 2.0 (14.5) 5.1 (36.9) -
1/2 BSP.F 10.2 (73.8) 3.1 (22.4) 8.2 (59.3) -
7/16-20 UNF - - - 2.0 (14.5)
3/4-16 UNF - - - 6.1 (44.1)
M 12×1.5 4.1 (29.7) 2.0 (14.5) 3.1 (22.4) 2.0 (14.5)
M 18×1.5 7.1 (51.4) 2.0 (14.5) 5.1 (36.9) 5.1 (36.9)
M 22×1.5 10.2 (73.8) 3.1 (22.4) 8.2 (59.3) 7.1 (51.4)

5-69
4) DISASSEMBLY
(1) Disassemble steering column from
steering unit and place the steering unit in
the holding tool.
Screw out the screws in the end cover(6-
off plus one special screw).

(770-3ATM) 5-72(1)

(2) Remove the end cover, sideways.

(770-3ATM) 5-72(2)

(3) Lift the gearwheel set (with spacer if

fitted) off the unit.
Take out the two O-rings.

(770-3ATM) 5-72(3)

(4) Remove cardan shaft.

(770-3ATM) 5-72(4)

5-70
(5) Remove distributor plate.

(770-3ATM) 5-73(1)

(6) Screw out the threaded bush over the

check valve.

(770-3ATM) 5-73(2)

(7) Remove O-ring.

(770-3ATM) 5-73(3)

(8) Take care to keep the cross pin in the

sleeve and spool horizontal. The pin can
be seen through the open end of the
spool. Press the spool inwards and the
sleeve, ring, bearing races and needle
bearing will be pushed out of the housing
together.

(770-3ATM) 5-73(4)

5-71
(9) Take ring, bearing races and needle
bearing from sleeve and spool. The outer
(Thin) bearing race can sometimes "stick"
in the housing, therefore check that it has
come out.

(770-3ATM) 5-74(1)

(10) Press out the cross pin. Use the special

screw from the end cover.

(770-3ATM) 5-74(2)

※ A small mark has been made with a

pumice stone on both spool and sleeve
close to one of the slots for the neutral
position springs (see drawing).
If the mark is not visible, remember to
leave a mark of your own on sleeve and
spool before the neutral position springs
are disassembled.

(770-3ATM) 5-74(3)

(11) Carefully press the spool out of the sleeve.

(770-3ATM) 5-74(4)

5-72
(12) Press the neutral position springs out of
their slots in the spool.

(770-3ATM) 5-75(1)

(13) Remove dust seal and O-ring.

(770-3ATM) 5-75(2)

(14) The steering unit is now completely

disassembled.

(770-3ATM) 5-75(3)

※ Cleaning
Clean all parts carefully in Shellsol K or
the like.
※ Inspection and replacement
Replace all seals and washers. Check all
par ts carefully and make any
replacements necessary.
※ Lubrication
Before assembly, lubricate all parts with
hydraulic oil.

5-73
5) ASSEMBLY
(1) Assemble spool and sleeve.
※ When assembling spool and sleeve only
one of two possible ways of positioning
the spring slots is correct. There are
three slots in the spool and three holes in
the sleeve in the end of the spool / sleeve
opposite to the end with spring slots.
Place the slots and holes opposite each (770-3ATM) 5-76(1)

other so that parts of the holes in the

sleeve are visible through the slots in the
spool.

(2) Place the two flat neutral position springs

in the slot.
Place the curved springs between the flat
ones and press them into place (see
assembly pattern).

(770-3ATM) 5-76(2)

※ Assembly pattern.
· Weak springs (blue)
2 - off flat, blue : Part no. 150-0748
2 - off curved, blue : Part no. 150-0749
· Blue set
Spare set : Part no. 150-4265

(770-3ATM) 5-76(3)

(3) Line up the spring set.

(770-3ATM) 5-76(4)

5-74
(4) Guide the spool into the sleeve. Make
sure that spool and sleeve are placed
correctly in relation to each other (see
page 3-76, No.(1)).

(770-3ATM) 5-77(1)

(5) Press the springs together and push the

neutral position springs into place in the
sleeve.

(770-3ATM) 5-77(2)

(6) Line up the springs and center them.

(770-3ATM) 5-77(3)

(7) Guide the ring down over the sleeve.

※ The ring should be able to rotate free of
the springs.

(770-3ATM) 5-77(4)

5-75
(8) Fit the cross pin into the spool / sleeve.

(770-3ATM) 5-78(1)

(9) Fit bearing races and needle bearing as

shown on below drawing.

(770-3ATM) 5-78(2)

※ Assembly pattern for standard bearings

1
1 Outer bearing race 2
2 Needle bearing 3
3 Inner bearing race
4 Spool
5 Sleeve 4

5
(770-3ATM) 5-78(3)

Installation instruction for O-ring

(10) Turn the steering unit until the bore is
horizontal. Guide the outer part of the
assembly tool into the bore for the spool /
sleeve.

(770-3ATM) 5-78(4)

5-76
(11) Grease O-ring with hydraulic oil and place
them on the tool.

(770-3ATM) 5-79(1)

(770-3ATM) 5-79(2)

(12) Hold the outer part of the assembly tool in

the bottom of the steering unit housing
and guide the inner part of the tool right to
the bottom.

(770-3ATM) 5-79(3)

(13) Press and turn the O-ring into position in

the housing.

(770-3ATM) 5-79(4)

5-77
(14) Draw the inner and outer parts of the
assembly tool out of the steering unit
bore, leaving the guide from the inner part
in the bore.

(770-3ATM) 5-80(1)

Installation instructions for lip seal

(15) Lubricate the lip seal with hydraulic oil and
place it on the assembly tool.

(770-3ATM) 5-80(2)

(770-3ATM) 5-80(3)

(16) Guide the assembly tool right to the

bottom.

(770-3ATM) 5-80(4)

5-78
(17) Press and turn the lip seal into place in
the housing.

(770-3ATM) 5-81(1)

(18) With a light turning movement, guide the

spool and sleeve into the bore.
※ Fit the spool set holding the cross pin
horizontal.

(770-3ATM) 5-81(2)

(19) The spool set will push out the assembly

tool guide. The O-ring are now in
position.

(770-3ATM) 5-81(3)

(20) Turn the steering unit until the bore is

vertical again. Put the check valve ball
into the hole indicated by the arrow.

(770-3ATM) 5-81(4)

5-79
(21) Screw the threaded bush lightly into the
check valve bore. The top of the bush
must lie just below the surface of the
housing.

(770-3ATM) 5-82(1)

(22) Grease the O-ring with mineral oil approx.

viscosity 500 cSt at 20 C .

(770-3ATM) 5-82(2)

(23) Place the distributor plate so that the

channel holes match the holes in the
housing.

(770-3ATM) 5-82(3)

(24) Guide the cardan shaft down into the bore

so that the slot is parallel with the
connection flange.

(770-3ATM) 5-82(4)

5-80
(25) Place the cardan shaft as shown - so that
it is held in position by the mounting fork.

(770-3ATM) 5-83(1)

(26) Grease the two O-rings with mineral oil

approx. viscosity 500 cSt at 20 C and
place them in the two grooves in the gear
rim. Fit the gearwheel and rim on the
cardan shaft.

(770-3ATM) 5-83(2)

(27) Important
Fit the gearwheel (rotor) and cardan shaft
so that a tooth base in the rotor is
positioned in relation to the shaft slot as
shown.
Turn the gear rim so that the seven
through holes match the holes in the
housing.

(770-3ATM) 5-83(3)

(28) Fit the spacer, if any.

(770-3ATM) 5-83(4)

5-81
(29) Place the end cover in position.

(770-3ATM) 5-84(1)

(30) Fit the special screw with washer and

place it in the hole shown.

(770-3ATM) 5-84(2)

(31) Fit the six screws with washers and insert

them. Cross-tighten all the screws and
the rolled pin.
·Tightening torque : 3.1±0.6 kgf·m
(22.4±4.3 lbf·ft)

(770-3ATM) 5-84(3)

(32) Place the dust seal ring in the housing.

(770-3ATM) 5-84(4)

5-82
(33) Fit the dust seal ring in the housing.

(770-3ATM) 5-85(1)

(34) Press the plastic plugs into the connection

ports.
※ Do not use a hammer!

(770-3ATM) 5-85(2)

5-83
3. STEERING CYLINDER
1) STRUCTURE

23 21

9,8 3 10 6,5 7 12,11 22 4 24, 25, 26 1 2 15,14 16 17 13 19 18

28,27 20

78095SE05

1 Tube assembly 11 O-ring 21 Pipe assy

2 Rod assy 12 Back-up ring 22 O-ring
3 Gland 13 Piston 23 Hexagon bolt
4 Du bushing 14 O-ring 24 U-bolt
5 Rod seal 15 Back-up ring 25 Hexagon nut
6 Back-up ring 16 Piston seal 26 Spring washer
7 Buffer ring 17 Wear ring 27 Spherical bearing
8 Dust wiper 18 Piston nut 28 Retaining ring
9 Retaining ring 19 Set screw
10 O-ring 20 Pipe assy

5-84
 2) TOOLS AND TIGHTENING TORQUE
(1) Tools
Tool name B Remark

B
L-wrench 5

Spanner 70

Wrench For gland

(-) Driver Small and large sizes
Torque wrench Capable of tightening with the specified torques

(2) Tightening torque

Torque
Part name Item Size
kgf·m lbf·ft
Gland 3 M110×2 88±9 637±65
Piston 13 M 45×2 75±8 542±58
Piston nut 18 M 45×2 100±10 723±72.3
Set screw 19 M 10×1.5 3.2±0.3 23.1±2.2

5-85
3) DISASSEMBLY
(1) Remove cylinder head and piston rod
① Hold the clevis section of the tube in a
vise.
※ Use mouth pieces so as not to damage
the machined surface of the cylinder
tube. Do not make use of the outside
piping as a locking means.

② Pull out piston rod (2) about 200 mm (7.8

in). Because the piston rod is rather
m
heavy, finish extending it with air 20
0m
pressure after the oil draining operation.

5-88(1)

③ Loosen and remove the gland (3).

※ Cover the extracted piston rod (2) with Wrench
rag to prevent it from being accidentally
damaged during operation.

3
2

5-88(2)

④ Draw out gland (3) and piston rod (2)

assembly together from cylinder tube (1).
Lift
※ Since the piston rod assembly is heavy
in this case, lift the tip of the piston rod
(2) with a crane or some means and
draw it out. However, when piston rod
(2) has been drawn out to
approximately two thirds of its length, lift Pull straight Oil pan
it in its center to draw it completely. sideways
5-88(3)

5-86
 ※ Note that the plated surface of piston rod
(2) is to be lifted. For this reason, do not
use a wire sling and others that may
damage it, but use a strong cloth belt or
a rope.

⑤ Place the removed piston rod assembly

on a wooden V-block that is set level.
Piston rod assy
※ Cover a V-block with soft rag.

Wooden block
5-89(1)

(2) Remove piston and gland assembly

① Remove the set screw (19). 15,14 16 17 13 19 18
② Remove the piston nut (18).
③ Remove piston assembly (13), back up
ring (15) and O-ring (14).

78095SE09

③ Remove the gland (3) assembly from Lift with a crane

piston rod (2).
※ If it is too heavy to move, move it by 9,8 6,5 7 4
striking the flanged part of gland (3) Plastic
hammer
with a plastic hammer.
Pull straight
※ Pull it straight with gland assembly lifted
with a crane.
Exercise care so as not to damage the
lip of rod bushing (4) and packing 3 2
78095SE21
(5,6,7,8,9) by the threads of piston rod
(2).

5-87
(3) Disassemble the piston assembly
① Remove wear ring (17) and piston seal 15,14 16 17
(16).
Remove back up ring (15) and O-ring
(14).
※ Exercise care in this operation not to
damage the grooves.

78095SE22

(4) Disassemble gland assembly

① Remove back up ring (12), and O-ring 9,8 10 6,5 7 12,11
(11).
② Remove O-ring (10).
③ Remove retaining ring (9) and dust wiper
(8).
④ Remove back up ring (6), rod seal (5)
and buffer ring (7).
※ Exercise care in this operation not to
78095SE23
damage the grooves.
※ Do not remove seal and ring, if does not
damaged.

5-88
4) ASSEMBLY
(1) Assemble gland assembly
※ Check for scratches or rough surfaces if
found smooth with an oil stone.
① Coat the inner face of gland (3) with
hydraulic oil.

78095SE34

② Coat dust wiper (8) with grease and fit

Press here(Straight down)
dust wiper (8) to the bottom of the hole of
dust wiper. Metal
At this time, press a pad metal to the 8
metal ring of dust seal.
③ Fit retaining ring (9) to the stop face.

78095SE24

④ Fit back up ring (6) and rod seal (5), and

buffer ring (7) to corresponding grooves,
in that order.
※ Coat each packing with hydraulic oil
Wrong Right
before fitting it.
※ Insert the backup ring until onside of it is
inserted into groove.

7577ASE42

※ Rod seal (5) has its own fitting direction.

Therefore, confirm it before fitting them. Push bar
※ Fitting rod seal (5) up side down may
damage its lip. Therefore check the
correct direction that is shown in fig.

78095SE43

5-89
 ⑤ Fit back up ring (12) to gland (3).
※ Put the backup ring in the warm water of 10 12,11 4
30~50˚C.
⑥ Fit O-ring (11, 10) to gland (3). 3
⑦ Fit bushing (4) to gland (3).

78095SE25

(2) Assemble piston assembly

※ Check for scratches or rough surfaces.
① If found smooth with an oil stone. 13
Coat the outer face of piston (13) with
hydraulic oil.

5-92(2)

② Fit piston seal (16) to piston

※ Put the piston seal in the warm water of 16
60~100˚C for more than 5 minutes.
※ After assembling the piston seal, press
its outer diameter to fit in.

5-92(3)

③ Fit wear ring (17) to piston (13).

15 14 17 13
④ Fit back up ring (15) and O-ring (14) to
piston (13).

5-92(4)

5-90
(3) Install piston and gland assembly
① Fix the piston rod assembly to the work
bench. Gland assembly Piston rod
② Apply hydraulic oil to the outer surface of
piston rod (2), the inner surface of piston
and gland.
③ Insert gland assembly to piston rod (2).

78095SE29

④ Fit piston assembly to piston rod.

⑤ Tighten piston nut (18) to piston rod (2). 2 Piston assembly 19
·Tightening torque : 100±10 kgf·m
(723±72 lbf·ft)
⑥ Tighten set screw (19) to piston nut (18).
·Tightening torque : 3.2±0.3 kgf·m
(23.1±2.2 lbf·ft)

18 78095SE30

(4) Overall assemble

Fix with bar
① Place a V-block on a rigid work bench.
Mount the cylinder tube assembly on it Lift
and fix the assembly by passing a bar
through the clevis pin hole to lock the
assembly.
Straight
② Insert the piston rod assembly in to the
cylinder tube assembly, while lifting and
moving the piston rod assembly with a Apply liquid packing
5-94(1)
crane.
※ Be careful not to damage piston seal by
thread of cylinder tube.
③ Fit gland to the tube.
·Tightening torque : 88±9 kgf·m Tube
(637±65 lbf·ft)
Piston rod

Wrench

Gland
5-94(2)

5-91
4. CENTER PIVOT PIN
1) CONSTRUCTION
Figure shows the construction of the center pivot pin assembly. This assembly serves to connect
the front frame with the rear frame; two sets of assemblies are provided, one each for the upper
and lower parts. The numbers in parentheses following the parts name denote the item numbers
shown in the figure in the disassembly and assembly procedures.

24 23 6,20 26 8 7 32

21
22 19,20
12
2
20,25
17
4,5 4,5
31
31
1
3 18
16
9
28 13,14,15
10

32 11 29,30 6,20

UPPER LOWER

78095SE13

1 Bearing 12 Dust seal 23 Hexagon bolt

2 Cover 13 Shim (0.1 t) 24 Hardened washer
3 Cover 14 Shim (0.5 t) 25 Hexagon bolt
4 Shim (0.1 t) 15 Shim (2.0 t) 26 Plate
5 Shim (0.5 t) 16 Bushing 28 Plate
6 Hexagon bolt 17 Cover 29 Hexagon bolt
7 Pin 18 Cover 30 Hardened washer
8 Collar 19 Hexagon bolt 31 Front frame
9 Collar 20 Hardened washer 32 Rear frame
10 Plate 21 Dust seal
11 Pin 22 Bushing

5-92
2) DISASSEMBLY
After supporting the front frame and the
rear frame as horizontally as possible using
wood blocks and jacks, disassemble as
fo l l o w s : I n o r d e r t o fa c i l i t a t e t h e
disassembly/assembly of the center pivot
pins, remove the drive shaft, hydraulic line
and steering cylinder first.
(1) Maintain the horizontal level of front frame
(31) and rear frame (32), and then UPPER
remove hexagon bolt (6, 23, 29), washer 24 23 6,20 26
(20, 24) and plate (26, 28).
(2) Take out upper pin (11) to the downside
using a metal punch.

31

28

32 11 29,30
78095SE14

(3) Maintain the front frame horizontal level,

LOWER
remove hexagon bolts (6) and then
7 32
remove the plate (10) and shims (13, 14,
15).
(4) Take out lower pin (7) to the upside using
a metal punch carefully.
31
(5) Jack up or lifting the front frame (31)
9
slightly, the collar (9) protrudes over the
rear frame.
Remove the collar (9). 10 13,14,15

(6) Lift the frame by passing the slinging wire 6,20

78095SE15
rope at four positions of front frame, in
order to separate it from the rear frame.
(7) Support the front frame safely.

5-93
 (8) Remove bolt (25), washer (20) and then
UPPER
take out cover (2) and shims (4, 5).
20,25 21 2
(9) Take out dust seal (21) from the cover (2).
(10) Remove the bearing (1), and dust seal 4,5
(21). 31

21 1
78095SE16

(11) Remove bolt (19), washer (20) and then LOWER

take out cover (17, 18) and shims (4, 5).
19,20 8 12 17
(12) Take out the dust seal (12) from the cover
(17, 18).
4,5
(13) Remove the bearing (1) and collar (8).
31

1 12 18
78095SE17

3) INSPECTION
(1) Check the bearing sliding surface for excessive wear, scorching or scratches; replace if
necessary.
(2) Replace all dust seals (12, 21) with new ones.
(3) Grind any pins (7, 11) dented with an oilstone or replace any pins abrasive excessively.
(4) Check inside cover (2, 3, 17, 18) and collar (8, 9) for dents or scratches; if any damage is found,
correct with a grinder or replace.
(5) The serviceable limit of pins and bushings is shown in the table below. Unit : mm

Std Serviceable limit

Item No. Name Remedy
dimension Outer dia Inner dia Clearance
7, 11 Pin 99.5
1 Tapered roller bearing 100 100.5 0.8 Replace
8, 9 Collar 100.5
12, 21 Dust seal When removed Replace

5-94
 4) ASSEMBLY

24 23 6,20 26 8 7 32

21
22 19,20
12
2
20,25
17
4,5 4,5
Clearance A 31
1 31
3 18
16
9
28 13,14,15
Clearance B

32 11 29,30 10 6,20

UPPER LOWER
78095SE19

Assemble the center pivot group by reversing the order of disassembly while paying close attention
to the following.
(1) Put the dust seal (12,21) into cover (2, 3, 17, 18).
※ Apply grease to the lip of the dust seal. Insert the dust seal so that the dust seal lip faces out and
punch four places on the outer circumference of the seal to lock it.
(2) Lower the temperature of the lower bearing cup to -75±5˚C (-103±9˚F ) and install it to front
frame until it contacts the bottom of the frame.
(3) Place the cover (3, 18).
(4) Coat lightly with oil and install lower bearing in bore in front frame. Coat lightly with oil and install
upper bearing in bore in upper front frame.
(5) Place the cover (2, 17) and hold in place with bolt (19, 25). At this time, adjust shims (4, 5) to
press the shoulder of bearing (1) against retainer.
Adjustment method of clearance A
① Install bearing (1) and cover (2, 17) without shim (4, 5)
Install four of bolt (19, 25) so that each bolt is separated by 90 degrees.
Tightening torque : 1.5~1.7 kgf m (10.8~12.3 lbf ft)
② Adjust shims (4, 5) in order to control the clearance A.
Clearance A : Below 0.1 mm
Shim thickness : 0.1 mm, 0.5 mm

5-95
 (5) Apply grease to lower collar (8) and insert it to the lower of roller bearing.
(6) After setting the bearing so that its upper surface is horizontal, tighten the all the bolt (19, 25).
After tightening, confirm that tapered roller bearing moves lightly ; if does not move smoothly, add
shims (4, 5).
Tightening Torque : 35~43 kgf m (253~311 lbf ft)
Apply loctite #243.
(7) Move the front frame and join it to the rear frame so that match the pin hole at the center.
(8) Apply grease to pin (11), bushing (22) and insert it into tapered roller bearing (1).
(9) Apply grease to lower collar (9) and insert it to the lower of roller bearing through rear frame (32).
(10) Apply grease to pin (7) and insert it into tapered roller bearing (1).
(11) Before tightening bolt (6), adjust shims (13, 14, 15) in order to control the clearance between the
plate (21) and rear frame (32).
Adjustment method of clearance B
① Install pin (7) and plate (10) without shim (13, 14, 15).
Install four of bolt (6) so that each bolt is separated by 90 degrees.
Tightening torque : 1.5~1.7 kgf m (10.8~12.3 lbf ft)
② Adjust shims in order to control the clearance B.
Clearance B : 0.1~0.2 mm
Shim thickness : 0.1 mm, 0.5 mm, 2.0 mm
(12) Tighten the all the bolts (6).
Tightening Torque : 35~43 kgf m (253~311 lbf ft)
Apply loctite #243.

5) TROUBLESHOOTING
Trouble Probable cause Remedy
Capscrew for fixing steering valve is loose Retighten
Faulty center pivot pin mounting bolts Retighten
Shock is felt when steering
Center pivot pins have worn out Readjust or replace
Faulty hydraulic system See hydraulic system
Fault fixing of connecting capscrews Retighten
Center pins have worn out Readjust or replace
Shock is felt when moving
Bearings of support unit have worn out Retighten
backward or forward
Drive shaft damaged See drive system
Faulty transmission See transmission system

5-96
 SECTION 6 WORK EQUIPMENT

Group 1 Structure and Function ----------------------------------------------------------------------------------- 6-1

Group 2 Operational Checks and Troubleshooting ----------------------------------------------------- 6-41
Group 3 Tests and Adjustments ----------------------------------------------------------------------------------- 6-52
Group 4 Disassembly and Assembly --------------------------------------------------------------------------- 6-67
 SECTION 6 WORK EQUIPMENT
GROUP 1 STRUCTURE AND FUNCTION

1. HYDRAULIC SYSTEM OUTLINE

The loader hydraulic system is a pilot operated, closed center system which is supplied with flow
from the variable displacement piston main hydraulic pump.
The loader system components are :
·Loader pump
·Main control valve
·Bucket cylinder
·Boom cylinders
·Remote control valve (Pilot control valve)
·Safety valve

Flow from the steering pump not used by the steering system leaves the flow amplifier EF port.
It flows to the inlet port plate of two section or three section block type main control valve.
The main control valve is load pressure independent flow distribution system which routes flow to the
boom, bucket or auxiliary cylinders (not shown) when the respective spools are shifted.
Flow from the loader pump is routed to the main control valve where pump outlet pressure is
reduced to pilot circuit pressure. The main control valve flow to the remote control valve.
The remote control valve routed flow to either end of each spool valve section in the main control
valve to control spool stroke.
A accumulator mounted on safety valve supplies a secondary pressure source to operated remote
control valve so the boom can be lowered if the engine is off.
The return circuit for the main hydraulic system have return filter inside the hydraulic tank. The return
filter uses a filter element and a bypass valve. The bypass valve is located in the upside of filter.

6-1
 2. HYDRAULIC CIRCUIT
32
PS
39 40
32

PS
38 T X1 X2 Dump Crawd
16 Up
Down
Down Up
MX
18 17
16 RH
RH LH
a2 a3 a4
LS
LH RH
BUCKET BOOM BOOM
B A CL CR 4 T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
7 MP
X X
P2
X

L R
)(

EF T2
T MT1 X

PP

HP LS HT

C2 12 C1
b1 A1 B1 A2 B2
A2 A1

B2 B1 17 b2 b3 b4
LH Dump Crawd

B 43 B 5 B.D/F B.U IN OUT

PARKING
A A T/M
DR DR
L R 1 3 4T P2 1.1 2.1
22
10 6 FRONT

P1
9 B
A1 T1 A1

31 31 14 23
A 20 20 P2
A2
T2
8 P T LS 19 B1A1 B2 A2
P
REAR
P1 T 20
15 A3
M LS
T 2 41
PS

T1
1 PS
X2
21
PS

X1
11 3 13 B
X3
42 A B
21
PS

PS1
X1 X2
35 32 25 P T P T
S
37 PS

P
36 30
PS

T
M 1 B1 2 B2 26
P1
M L 33
34 27 P
T/M
M
T/M
28 3 T/M T

S1 L2 L1 S2 L4 L3 24

29
78096WE01

1 Steering pump 16 Boom cylinder 31 Check valve

2 Loader pump 17 Bucket cylinder 32 Pressure sensor
3 Fan & brake pump 18 Steering cylinder 33 Fan motor
4 Main control valve 19 Cut-off valve 34 Pump motor (opt)
5 Remote control valve 20 Accumulator 35 Check block (opt)
6 Steering unit 21 Pressure sensor 36 Pressure sensor (opt)
7 Flow amplifier 22 Brake valve 37 Check valve (opt)
8 Controller (opt) 23 Pressure switch 38 Ride control valve (opt)
9 Joystick (opt) 24 Hydraulic tank 39 Accumulator (opt)
10 Proportional valve (opt) 25 Air breather 40 Accumulator (opt)
11 LS compensating valve (opt) 26 Return filter 41 Quick coupler cylinder (opt)
12 Shuttle valve (opt) 27 By pass valve 42 Solenoid valve (opt)
13 Pressure sensor (opt) 28 Strainer 43 Stop valve (opt)
14 Safety valve 29 Oil cooler
15 Shuttle valve 30 Pressure filter

6-2
 3. WORK EQUIPMENT HYDRAULIC CIRCUIT

16 Up
Down
Dump Crawd Down Up

17
16 RH
RH LH
a2 a3 a4
LS
BUCKET BOOM BOOM
4 T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

T2
MT1 X

b1 A1 B1 A2 B2

17 b2 b3 b4
LH Dump Crawd

5 B.D/F B.U IN OUT

Return line
1 3 4T P2 1.1 2.1

A1

31 31 14
Flow amplifier
EF port

P1 T
Flow amplifier 15
LS port X1 X2
X3

X1 X2 Return line
32 25
PS
Steering system

1 B1 2 B2 26
27
T/M
T/M
28
S1 L2 L1 S2 L4 L3 24 Fan & brake pump

78096WE02

1 Steering pump 15 Shuttle valve 26 Return filter

2 Loader pump 16 Boom cylinder 27 Bypass valve
4 Main control valve 17 Bucket cylinder 28 Strainer
5 Remote control valve 24 Hydraulic tank 31 Check valve
14 Safety valve 25 Air breather 32 Pressure sensor

6-3
 1) WHEN THE RCV LEVER IS IN THE RAISE POSITION

Down
16 Up
Dump Crawd Down Up

17
16 RH
RH LH
a2 a3 a4
LS
BUCKET BOOM BOOM
4 T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

T2
MT1 X

b1 A1 B1 A2 B2

17 b2 b3 b4
LH Dump Crawd

5 B.D/F B.U IN OUT

Return line
1 3 4T P2 1.1 2.1

A1

31 31 14
Flow amplifier
EF port

P1 T
Flow amplifier 15
LS port X1 X2
X3

X1 X2 Return line
32 25
PS
Steering system

1 B1 2 B2 26
27
T/M
T/M
28
S1 L2 L1 S2 L4 L3 24 Fan & brake pump

78096WE03

· When the RCV lever (5) is pulled back, the boom spool is moved to raise position by pilot oil
pressure from port 3 of RCV.
· The oil from loader pump (2) flows into main control valve (4) and then goes to the large chamber
of boom cylinder (16) by pushing the load check valve of the boom spool.
· The oil from the small chamber of boom cylinder (16) returns to hydraulic oil tank (24) through the
boom spool at the same time.
· When this happens, the boom goes up.

6-4
 2) WHEN THE RCV LEVER IS IN THE LOWER POSITION

Down
16 Up
Dump Crawd Down Up

17
16 RH
RH LH
a2 a3 a4
LS
BUCKET BOOM BOOM
4 T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

T2
MT1 X

b1 A1 B1 A2 B2

17 b2 b3 b4
LH Dump Crawd

5 B.D/F B.U IN OUT

Return line
1 3 4T P2 1.1 2.1

A1

31 31 14
Flow amplifier
EF port

P1 T
Flow amplifier 15
LS port X1 X2
X3

X1 X2 Return line
32 25
PS
Steering system

1 B1 2 B2 26
27
T/M
T/M
28
S1 L2 L1 S2 L4 L3 24 Fan & brake pump

78096WE04

· When the RCV lever (5) is pushed forward, the boom spool is moved to lower position by pilot
pressure.
· The oil from loader pump (2) flows into main control valve (4) and then goes to small chamber of
boom cylinder (16) by pushing the load check valve of the boom spool.
· The oil returned from large chamber of boom cylinder (16) returns to hydraulic tank (24) through
the boom spool at the same time.
· When the lowering speed of boom is faster, the return oil from the large chamber of boom cylinder
combines with the oil from the pump through the regeneration check valve, and flows into the small
chamber of the cylinder.
This prevents cylinder cavitation by the negative pressure when the pump flow cannot match the
boom down speed.

6-5
 3) WHEN THE RCV LEVER IS IN THE FLOAT POSITION

Down
16 Up
Dump Crawd Down Up

17
16 RH
RH LH
a2 a3 a4
LS
BUCKET BOOM BOOM
4 T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

T2
MT1 X

b1 A1 B1 A2 B2

17 b2 b3 b4
LH Dump Crawd

5 B.D/F B.U IN OUT

Return line
1 3 4T P2 1.1 2.1

A1

31 31 14
Flow amplifier
EF port

P1 T
Flow amplifier 15
LS port X1 X2
X3

X1 X2 Return line
32 25
PS
Steering system

1 B1 2 B2 26
27
T/M
T/M
28
S1 L2 L1 S2 L4 L3 24 Fan & brake pump

78096WE05

· When the RCV lever (5) is pushed further forward from the lower position, the pilot pressure
reaches to 13~15bar, then the boom spool is moved to floating position.
· The work ports (A2), (B2), (A3), (B3) and the small chamber and the large chamber are connected
to the return passage, so the boom will be lowered due to it's own weight.
· In this condition, when the bucket is in contact with the ground, it can be move up and down in
accordance with the shape of the ground.

6-6
 4) WHEN THE RCV LEVER IS IN THE DUMP POSITION

Down
16 Up
Dump Crawd Down Up

17
16 RH
RH LH
a2 a3 a4
LS
BUCKET BOOM BOOM
4 T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

T2
MT1 X

b1 A1 B1 A2 B2

17 b2 b3 b4
LH Dump Crawd

5 B.D/F B.U IN OUT

Return line
1 3 4T P2 1.1 2.1

A1

31 31 14
Flow amplifier
EF port

P1 T
Flow amplifier 15
LS port X1 X2
X3

X1 X2 Return line
32 25
PS
Steering system

1 B1 2 B2 26
27
T/M
T/M
28
S1 L2 L1 S2 L4 L3 24 Fan & brake pump

78096WE06

· If the RCV lever (5) is pushed right, the bucket spool is moved to dump position by pilot oil pressure
from port 2 of RCV.
· The oil from loader pump (2) flows into main control valve (4) and then goes to the small chamber
of bucket cylinder (17) by pushing the load check valve of the bucket spool.
· The oil at the large chamber of bucket cylinder (17) returns to hydraulic tank (24).
· When this happens, the bucket is dumped.
· When the dumping speed of bucket is faster, the oil returned from the large chamber of bucket
cylinder combines with the oil from the pump, and flows into the small chamber of the cylinder.
This prevents cylinder cavitation by the negative pressure when the pump flow cannot match the
bucket dump speed.

6-7
 5) WHEN THE RCV LEVER IS IN THE ROLL BACK (retract) POSITION

Down
16 Up
Dump Crawd Down Up

17
16 RH
RH LH
a2 a3 a4
LS
BUCKET BOOM BOOM
4 T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

T2
MT1 X

b1 A1 B1 A2 B2

17 b2 b3 b4
LH Dump Crawd

5 B.D/F B.U IN OUT

Return line
1 3 4T P2 1.1 2.1

A1

31 31 14
Flow amplifier
EF port

P1 T
Flow amplifier 15
LS port X1 X2
X3

X1 X2 Return line
32 25
PS
Steering system

1 B1 2 B2 26
27
T/M
T/M
28
S1 L2 L1 S2 L4 L3 24 Fan & brake pump

78096WE07

· If the RCV lever (5) is pulled left, the bucket spool is moved to roll back position by pilot oil pressure
from port 4 of RCV.
· The oil from loader pump (2) flows into main control valve (4) and then goes to the large chamber
of bucket cylinder by pushing the load check valve of the bucket spool.
· The oil at the chamber of bucket cylinder (17) returns to hydraulic tank (24).
· When this happens, the bucket roll back.

6-8
4. MAIN PUMP (LOADER PUMP)
1) STRUCTURE (1/2)
This loader pump is variable displacement piston pump.

L3 X2 B2
X2

B2

T/M

S2 L4 L3

Hydraulic circuit
L4 S2

78096WE88

Port Port name Port size

B2 Pressure port SAE 1 1/4"
S2 Suction port SAE 2 1/2"
L3, L4 Case drain port 1 5/16-12UN
X2 Pilot pressure port 7/16-20UNF

6-9
· STRUCTURE (2/2)
27
23

6,31 2

51

33 16
12

1-2

1-1

30

7
17
22

15
20
25 78096WE11

1 Rotary group 8 Drive shaft 23 O-ring

1-1 High speed rotary group 12 Adjustment shim 25 V-ring
1-2 Control plate 15 Taper roller bearing 27 Socket screw
2 Adjusting piece 16 Taper roller bearing 30 Locking screw
5 Pump housing 17 Bearing liner 31 Double break-off pin
6 Port plate 20 Shaft seal ring 33 Cylinder pin
7 Swash plate 22 O-ring 51 Control valve

6-10
2) FUNCTION

1 2 3 4 5 6

LS pressure

12 13
X

11

8 9 10 L B

X L1 S

13 12 4 10
75796WE33

1 Drive shaft 6 Counter spring 11 Control plate

2 Swash plate 7 Pressure & flow compensator valve 12 Pressure compensator spool
3 Shoe plate 8 Piston shoe 13 Flow compensator spool
4 Counter piston 9 Cylinder
5 Piston 10 Control piston

The steering pump and loader pump are variable displacement piston pump. The steering pump
and loader pump are flow controlled by LS signal. When the steering and loader are not being
used, the pumps are at low pressure standby.
The load sensing pressure that is sensed from steering and loader hydraulic systems flows to flow
compensator spool (13). This spool keeps the pump output at a level that is necessary to fulfill the
requirements for the system flow and for the pressure.
The pressure compensator spool (12) also limits maximum system pressure. The pressure
compensator spool (12) prevents damage to the steering and loader hydraulic components from
excessive pressure.
The swivel angle of the pumps is controlled by counter piston (4) and control piston (10). Counter
spring (6) cause swash plate (2) to move at maximum displacement or causes swash plate (2) to
upstroke.
Control piston (10) has a larger area (diameter) than counter piston (4). Control piston (10) causes
swash plate (2) to destroke the pump.
Flow compensator spool (13) and/or pressure compensator spool (12) changes pump output by
regulating the pump discharge pressure that is acting on control piston (10).

6-11
Control piston (10) diameter is larger than counter piston (4) diameter, the oil pressure that is
acting against control piston (10) overcomes the force of counter spring (6). The oil pressure than
causes the pump to destroke.
Pressure and flow compensator valve (7) also controls the maximum output of pump pressure.
When steering and loader pressure rises above pressure compensator setting, pressure
compensator spool (12) overrides flow compensator spool (13). This causes the pump to destroke.

6-12
(1) Upstroking
14
1 2 4 6

15

LS pressure

12 13
X

21

22
10 L B

16

LS pressure oil
System pressure oil
Return oil L1 S
4 10
17 18 19 20 13 23 12
75796WE35

1 Drive shaft 13 Flow compensator spool 19 LS line from the metering pump
2 Swash plate 14 Case drain 20 Cavity
4 Counter piston 15 Passage 21 Passage
6 Counter spring 16 Passage 22 Passage
10 Control piston 17 Spring 23 Cavity
12 Pressure compensator spool 18 Spring

Upstroking of the pump occurs as flow demand from loader and steering system.
The increased flow demand causes a LS pressure in LS line (19). The LS pressure in LS line (19)
combines with the force of spring (18) in cavity (20).
The force of spring (18) causes pump pressure to be higher than the LS pressure (19).
If the combination of LS pressure and of spring force is greater than the pump discharge pressure,
this difference pressure causes spool (13) to move right. As spool (13) moves right, the spool (13)
blocks the flow of supply oil to control piston (10). Pump swash plate (2) is controlled by pressure
and flow as much as hydraulic system requests.
When the oil flow to control piston (10) is blocked, the pilot oil in passage (22) drains to passage
(23). The oil then flows past pressure compensator spool (12) and through passage (16) into the
housing and via the drain line (14) to tank.
Supply oil flows through passage (15) to counter piston (4). The oil acts against counter piston (4).
The oil combines with the force of counter spring (6). This causes swash plate (2) to upstroke.
This also causes the pump flow to increase. As flow requirements are satisfied, the pump output
pressure increase. The pressure increases until the pressure in passage (15) moves flow
compensator spool (13) up to be satisfied with system requirement for pressure and flow.
·Pump discharge pressure = force of spring (18) + LS pressure (19)

6-13
(2) Destroking

14
1 2 4 6

15

LS pressure

12 13
X

21

22
10 L B

16

LS pressure oil
System pressure oil
Return oil L1 S
4 10
17 18 19 20 13 23 12
75796WE34

1 Drive shaft 13 Flow compensator spool 19 LS line from the metering pump
2 Swash plate 14 Case drain 20 Cavity
4 Counter piston 15 Passage 21 Passage
6 Counter spring 16 Passage 22 Passage
10 Control piston 17 Spring 23 Cavity
12 Pressure compensator spool 18 Spring

The decreased flow demand causes a LS pressure in line (19). The LS pressure in line (19)
combines with the force of spring (18) in cavity (20).
This combination of LS pressure and of spring force is less than the pump pressure in passage
(21). This causes flow compensator spool (13) to move left.
Pump oil now flows through passage (15). The oil then flows past flow compensator spool (13),
through passage (22), and then to control piston (10).
The pump pressure behind control piston (10) is now greater than the combined force of counter
piston(4) and of counter spring (6). The angle of swash plate (2) decreases.
This decreases the pump output and the system pressure.
When the lower flow requirements are met, flow compensator spool (13) moves right up to the
balanced position. Swash plate (2) maintains an angle that is sufficient to provide the lower
required pressure. If the operator does not turn the steering wheel and does not move RCV, then
the pump will return to low pressure standby.
※ Control piston → Changes pump displacement ; influenced by controller.
Counter piston → Helps to change pump displacement but no possible to control this piston.

6-14
(3) Low pressure standby

14
1 2 4 6

15

LS pressure

12 13
X

21

22 L
10 24 B

16

LS pressure oil
System pressure oil
Return oil L1 S
4 10
17 18 19 20 23 13 12
75796WE36

1 Drive shaft 13 Flow compensator spool 19 LS line from the metering pump
2 Swash plate 14 Case drain 20 Cavity
4 Counter piston 15 Passage 21 Passage
6 Counter spring 16 Passage 22 Passage
10 Control piston 17 Spring 23 Cavity
12 Pressure compensator spool 18 Spring 24 Cross-drilled hole

Low pressure standby constitutes the following condition: a running engine and inactive steering
and loader. There are no flow demands on the pump or pressure demands on the pump.
Therefore, there is no LS pressure in line (19).
Before you start the engine, counter spring (6) holds swash plate (2) at the maximum angle. As the
pump begins to turn, oil begins to flow and pressure increases in the system.
Because of close centered steering control valve and close centered loader hydraulic system.
As this pressure increase, the pressure pushes flow compensator spool (13) against spring (18).
This causes flow compensator spool (13) to move left. This opens passage (23) in order to allow
pressure oil to flow to control piston (10).
The oil acts against control piston (10) in order to overcome the force of counter spring (6). The oil
causes control piston (10) to move to the left.
When control piston (10) moves to the left, the piston moves swash plate (2) toward the minimum
angle. Control piston (10) continues to move to the left until cross-drilled hole (24) allows the oil to
drain to the case.

6-15
 Cross-drilled hole (24) limits the maximum travel of control piston (10) to the left. The pump
supplies a sufficient amount of flow that compensates for system leakage. The pump also supplies
a sufficient of flow that compensates for leakage to the pump case. The leakage to the pump case
is a result of the cross-drilled hole. The pump maintains low pressure standby. Low pressure
standby pressure should not exceed 40 bar (580 psi).
※ Low pressure standby will vary in the same pump as the system leakage or the pump leakage
increases. The pump will upstroke slightly in order to compensate for the increasing leakage.
Control piston (10) will cover more of the cross-drilled hole.

6-16
(4) High pressure stall

14
1 2 4 6

15

LS pressure

12 13
X

21

22 L
10 24 B

16

LS pressure oil
System pressure oil
Return oil L1 S
4 10
17 18 19 20 23 13 12
75796WE36

1 Drive shaft 13 Flow compensator spool 19 LS line from the metering pump
2 Swash plate 14 Case drain 20 Cavity
4 Counter piston 15 Passage 21 Passage
6 Counter spring 16 Passage 22 Passage
10 Control piston 17 Spring 23 Cavity
12 Pressure compensator spool 18 Spring

When the hydraulic system stalls under load or when the cylinders reach the end of the stroke, the
main system pressure increases. But LS pressure (19) is regulated by LS relief valve on steering
system and loader system. The pressure difference between discharged pump and LS pressure
equal to spring (18). It means no flow is necessary. Therefore, discharged pressure push flow
compensator spool (13) left . Supply oil now flows past flow compensator spool (13) and through
passage (23). The oil flows past flow compensator spool (13) and into passage (22). The oil then
flows to control piston (10).
Pump swash plate (2) will be minimum displacement if the operator does not turn the steering
wheel and RCV, then the pump will return to low pressure standby.

6-17
(5) Adjustment of flow control
Flow compensator setting must be carried out following procedures and conditions.
① Conditions
- Engine is running (at high or low idle).
- RCV is operated slowly (example : Boom up).
- Pressure gauges are installed.
※ Discharge pump flow should be less than max pump flow.

② Procedures
- Loosening the hexagon nut (2).
- Adjusting screw (1) of flow controller by tightening or loosing the screw (1).
·Flow setting : ΔP = Gauge A - Gauge B
·Specification : Steering pump (27 bar) / Loader pump (22 bar)

Flow compensator Gauge B

X
2 1
Gauge A
-16 bar/rev
+16 bar/rev B

S L1 L
75796WE37

(6) Adjustment of pressure control

Pressure compensator setting must be carried out following procedures and conditions.
① Conditions
- Engine is running.
- System is at relief condition.

② Procedures
- Loosening the hexagon nut (2).
- Adjusting screw (1) of pressure controller by tightening or loosing the screw (1).
·Maximum pressure setting = Gauge A
·Specification : Steering pump (250 bar) / Loader pump (300 bar)
Pressure compensator
X

Gauge A

-52 bar/rev
+52 bar/rev

S L1 L
2 1 75796WE38

6-18
5. REMOTE CONTROL VALVE
1) STRUCTURE

4,3,1
4 1
10 3 2 12
30
11

2
33 30

4,3,1 14 32
40
15
40
4 1 42
20 3 2

22
21
23 4 1

3 2
25

26

45

7707WE11

1 Handle 14 Shim set 26 Bushing kit

3 Lever kit 15 Joint 30 Plunger kit
4 Bellows 20 Flange 32 Regulating unit
5 Nut 21 Solenoid complete 33 Regulating unit
10 Bracket 22 Plunger kit 40 Spring set
11 Detent kit 23 Plunger guide 42 Prefeel point kit
12 Plunger kit 25 Electric bracket 45 Plug set

6-19
2) OPERATION

T P

B.D/F B.U IN OUT

1 34 2
HYDRAULIC CIRCUIT
(3 Electromagnetic locks)

Electromagnetic lock 9

10

11 5

4
12
(1) Hydraulic functional principle 3
Pilot devices with end position locks operate as
7 2
direct operated pressure reducing valves.
They basically comprise of control lever (1), four T 8
x
pressure reducing valves, housing (6) and locks. P

Each pressure reducing valve comprises of a

control spool (2), a control spring (3), a return 6
spring (4) a plunger (5).
At rest, control lever (1) is held in its neutral position Port 4 Port 2
by return springs (4). Ports (1, 2, 3, 4) are 7707WE12

connected to tank port T via drilling (8).

When control lever (1) is deflected, plunger (5) is pressed against return spring (4) and control
spring (3).
Control spring (3) initially moves control spool (2) downwards and closes the connection between
the relevant port and tank port T. At the same time the relevant port is connected to port P via
drilling (8). The control phase starts as soon as control spool (2) finds its balance between the
force from control spring (3) and the force, which results from the hydraulic pressure in the
relevant port (ports 1, 2, 3 or 4).
Due to the interaction between control spool (2) and control spring (3) the pressure in the relevant
port is proportional to the stroke of plunger (5) and hence to the position of control lever (1).
This pressure control which is dependent on the position of the control lever and the
characteristics of the control spring permits the proportional hydraulic control of the main
directional valves and high response valves for hydraulic pumps.
A rubber bellows (9) protects the mechanical components in the housing from contamination.

6-20
(2) End position lock
Only those control ports, for which it is necessary to hold the control lever in a deflected position
are equipped with end position locks.
Electromagnetic lock
An additional spring (7), which is fitted below an additional plate (12) warns, by means of an
increased force, which is required for compressing this spring, that the plunger (5) and the control
lever (1) have almost reached their end position.
When this threshold is overcome, a ring (10) contacts the solenoid armature (11) ; if the solenoid
is energized, then control lever (1) is held in its end position by magnetic force.
This lock is released automatically when the solenoid is deenergized.

6-21
6. MAIN CONTROL VALVE
1) STRUCTURE (1/3)
·Type : Closed center, Load pressure - Independent - Flow - Distribution

MP

MT1

A4 B4
a4 b4

A3 B3
a3 b3

T2 P2

LS
pst
a2 A2 B2 b2
B2 A2
A1 B1
a1 b1
B1 A1

T P

VIEW A

a2 a3 a4
LS

T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

Bucket Boom Boom

T2
MT1 X

b1 A1 B1 A2 B2

b2 b3 b4
Hydraulic circuit
78096WE10

Port Port name Port size Port Port name Port size
P From main pump SAE 1" a2, b2 Boom pilot port 11/16-16UN
T To hydraulic tank SAE 1 1/4" a3, b3 Auxiliary pilot port 11/16-16UN
A1, B1 To bucket cylinder port SAE 3/4" LS Load sensing port 9/16-18UNF
A2, B2, A3, B3 To boom cylinder port SAE 3/4" Pst To RCV P port 9/16-18UNF
a1, b1 Bucket pilot port 11/16-16UN - - -

6-22
 STRUCTURE (2/3)

62
63 60

61
36 38

37
38 79

35

50
80

50

79
74
38

37
38
36
80
35

65

33

33 32
11
79
31

30

86
102 71

84
165
74

79
85

78096WE13

11 Housing 38 O-ring 74 Compensator valve

30 O-ring 50 Housing 79 Pressure valve
31 O-ring 60 Plate 80 Plug screw
32 O-ring 61 Stud 84 Flow regulator
33 O-ring 62 Hexagon nut 85 Precharge valve
35 O-ring 63 Washer 86 Pressure reducing valve
36 O-ring 65 Sandwich plate 102 Locking screw
37 O-ring 71 Shuttle valve 165 Pressure relief valve

6-23
 STRUCTURE (3/3)
23
21

20

12 44
96
90
91
39 43
23
21
90
91
50 39
95 19
95

39 13
91 50 42
90
96 90 23
12 21
91
21 34 13
23
39
19
65

20

34
91
90
41
96
12
23
21 90
23 91
11
34
20

12
20
96 78096WE14

11 Housing 34 O-ring 65 Sandwich plate

12 Cover 39 O-ring 90 Compression spring
13 Cover 41 Spool 91 Spring retainer
19 Bolt 42 Spool 95 Spring retainer
20 Bolt 43 Spool 96 Spring retainer
21 Throttle check valve 44 Spool
23 Threaded steel pipe fitting 50 Housing

6-24
2) FUNCTION

4
6
A B

a T P b

2 5 3 1 7

3
a2 a3 a4
LS

T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

Bucket Boom 5 Boom

T2
MT1 X

b1 A1 B1 A2 B2

4 b2 6 b3 b4
Hydraulic circuit

78096WE15

1 Housing 4 Counter balance valve 7 Spring chamber

2 Spool 5 Regeneration check valve
3 Pressure compensator 6 Port relief valve

6-25
(1) Control block
Proportional direction valve to the LUDV principle (Load pressure - Independent - Flow -
Distribution)
(2) Actuator control
At the spool (2) the direction and volume of flow is determined that flows to the actuator
connections (A or B).
The spring chambers (7) are supplied with pilot pressure either via the pilot connections a and b
hydraulic control.
The value of the pilot pressure within the spring chamber (7) determines the stroke of the spool
(2).
The pressure compensator (3) controls the pressure differential at the spool (2) and therefore, the
flow to the actuators (A, B).
(3)
3) Loader pressure compensation (LUDV)
The control block works to the LUDV principle. In this load - sensing version the pressure
compensators (3) are located between the spool (2) and the actuator connections (A, B).
The highest load pressure of all of the actuators involved is applied to all of the pressure
compensators. In parallel it is also applied to the pump.
If the pump flow is insufficient for all of the functions, then all work movements are reduced in
speed by the same ratio.
(4) Pressure safety, actuator connections
Large nominal size port relief valve (6) with combined anti-cavitation functions protect the
actuators from overloads and cavitation.
(5) Float position
The float position is obtained by means of a 4-position spool.
(6) Regeneration
(6
To prevent cavitation, with negative loads (e. g. dump or lowering), the tank port is pre-loaded via
counter balance valve (4) and is fed with oil via the regeneration check valve (5) downstream of
the pressure compensator.

6-26
3) BOOM SECTION OPERATION
(1) Spool in neutral

A2,A3 B2,B3

a2,a3 T P b2,b3

a2 a3 a4
LS

T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

Bucket Boom Boom

T2
MT1 X

b1 A1 B1 A2 B2

b2 b3 b4

Hydraulic circuit

78096WE51

When the boom spool is in neutral position, oil from the pump will be blocked.
Then, the pumps are at low pressure stand by.

6-27
(2) Boom raise position

A2,A3 B2,B3

T P b2,b3
a2,a3

a2 a3 a4
LS

T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

Bucket
Boom Boom
T2
MT1 X

b1 A1 B1 A2 B2

b2 b3 b4

Hydraulic circuit

78096WE52

When the pilot pressure is led to the port b2, b3 the boom spool moved to raise position.
Oil from the pump flows to the cylinder port B2, B3 and oil from the cylinder flows into the tank
passage through the cylinder port A2, A3.

6-28
(3) Boom lower position

A2,A3 B2,B3

T P b2,b3
a2,a3

6
a2 a3 a4
LS

T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

Bucket Boom
6
Boom
T2
MT1 X

b1 A1 B1 A2 B2

b2 b3 b4

Hydraulic circuit

78096WE53

When the pilot pressure is led to the port a2, a3, the boom spool moved to lower position.
Oil from the pump flows to the cylinder port A2, A3 and oil from the cylinder flows into the tank
passage through the cylinder port B2, B3.
When the lowering speed of boom is faster, the return oil from the large chamber of boom
cylinder combines with the oil from the pump through regeneration check valve (6), and flows into
the small chamber of the cylinder. This prevents cylinder cavitation by the negative pressure when
the pump flow cannot match the boom down speed.

6-29
(4) Boom float position

A2,A3 B2,B3

T P b2,b3
a2,a3

a2 a3 a4
LS

T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

Boom Boom
Bucket

T2
MT1 X

b1 A1 B1 A2 B2

b2 b3 b4

Hydraulic circuit

78096WE54

When the boom spool is located in float position, the oil from the pump will be blocked.
The cylinder ports (A2, A3, B2, B3) are connected to the tank passage, so the boom will be
lowered due to it's own weight.

6-30
4) BUCKET SECTION OPERATION
(1) Spool in neutral

A1 B1

T P b1
a1

A1 B1

a2 a3 a4
LS

T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

Bucket Boom Boom

T2
MT1 X

b1 A1 B1 A2 B2

b2 b3 b4

Hydraulic circuit

78096WE55

When the bucket spool is in neutral position, oil from the pump will be blocked.
Then, the pumps are at low pressure standby.

6-31
(2) Bucket rollback position

A1 B1

a1 T P b1

B1
A1

a2 a3 a4
LS

T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

Boom Boom
Bucket
T2
MT1 X

b1 A1 B1 A2 B2

b2 b3 b4

Hydraulic circuit

78096WE56

When the pilot pressure is led to the port b1, the bucket spool moved to rollback position.
Oil from the pump flows to the cylinder port B1 and oil from the cylinder flows into the tank
passage through the cylinder port A1.

6-32
(3) Bucket dump

A1 B1

T P b1
a1

A1 B1
6

a2 a3 a4
LS

T P a1 A1 B1 A2 B2 pst A3 B3 A4 B4
X X
MP P2
X

)(

Bucket
Boom Boom

T2
MT1 X

6
X

b1 A1 B1 A2 B2

b2 b3 b4

Hydraulic circuit

78096WE57

When the pilot pressure is led to the port a1, the bucket spool moved to dump position.
Oil from the pump flows to the cylinder port A1, through the load holding valve and oil from the
cylinder flows into the tank passage through the cylinder port B1.
When the dumping speed of bucket is faster, the return oil from the large chamber of bucket
cylinder combines with the oil from the pump through regeneration check valve (6), and flows into
the small chamber of the cylinder. This prevents cylinder cavitation by the negative pressure when
the pump flow cannot match the bucket dump speed.

6-33
7. SAFETY VALVE
1) STRUCTURE
2
4

5
P1

T
A1
A1

3 2
1

P1 T
Hydraulic circuit

Port Port name Port size

P1 From MCU PF 3/8"
A1 Supply to RCV lever PF 1/4"
T To hydraulic tank PF 1/4"
75796WE16

1 Bowl and element assy 4 Solenoid valve

2 Check valve 5 Accumulator
3 Cartridge

2) OPERATION
This valve is used to cut off the pilot circuit.
When the pilot cut off switch in the cab is pressed to ON position, the solenoid valve is activated
and then the pilot oil flow into the pilot circuit.
The accumulator satisfied short term peak power demands and is a source of emergency power in
case of main circuit pressure failures.

6-34
8. BOOM AND BUCKET CYLINDER
The boom cylinders are two unit and the bucket cylinder is one unit. They use a bolt on rod guide.
The piston (14) threads on to the rod (2) and is retained by a nut (20) and set screw (21).
The piston seals against the tube (1) with piston seal (15). Two wear rings (16) are located on each
side of the piston seal.
The gland (3, the rod guide) seals against the tube with an O-ring (12). The cylinder thread seals
against the rod with a lip type buffer ring (8) and a rod seal (5). A dust wiper (9) cleans the rod when
it is retracted.
1) BOOM CYLINDER

22 25 26 27 23, 24

9,10 6, 7 3 8 11 12,13 4, 5 1 2 14 17 16 15 18,19 20 21 29 28

78096WE17

1 Tube assembly 11 O-ring 21 Set screw

2 Rod assembly 12 O-ring 22 Bolt
3 Gland 13 Back up ring 23 Bushing
4 Bushing 14 Piston 24 Dust seal
5 Snap ring 15 Piston seal 25 Band assembly
6 Rod seal 16 Wear ring 26 Pipe assembly
7 Back up ring 17 Dust ring 27 Pipe assembly
8 Buffer ring 18 O-ring 28 O-ring
9 Dust wiper 19 Back up ring 29 Bolt
10 Snap ring 20 Lock nut

6-35
2) BUCKET CYLINDER

23, 25 22 28 27 29 24, 26

9,10 6, 7 3 8 11 12,13 4, 5 1 2 14 17 16 15 18,19 20 21 31 30

78096WE18

1 Tube assembly 12 O-ring 23 Bushing

2 Rod assembly 13 Back up ring 24 Bushing
3 Gland 14 Piston 25 Dust seal
4 Bushing 15 Piston seal 26 Dust seal
5 Snap ring 16 Wear ring 27 Band assembly
6 Rod seal 17 Dust ring 28 Pipe assembly
7 Back up ring 18 O-ring 29 Pipe assembly
8 Buffer ring 19 Back up ring 30 O-ring
9 Dust wiper 20 Lock nut 31 Bolt
10 Snap ring 21 Set screw
11 O-ring 22 Bolt

6-36
9. HYDRAULIC OIL TANK
1) STRUCTURE
· The oil from the hydraulic tank is sent from the pump through main control valve to the cylinders.
In the return circuit, the oil from various parts merges.
· A part of oil is cooled in the oil cooler, passes through the hydraulic filter and returns to the
hydraulic tank (1).
· If the hydraulic return oil filter becomes clogged, return filter bypass valve (16) acts to allow the oil
to return directly to the hydraulic tank (1). This prevents damage to the hydraulic filter (14). The
bypass valve (16) is also actuated when negative pressure is generated in the circuit.

1 Hydraulic tank wa
22
2 Cover
21
20 3 Cover
5
4 Cover
2 5 Bolt
6 O-ring
6
5
7 O-ring
17 8 Bolt
4 12 Suction pipe
7 13 Strainer
13
15 14 Return filter
16 15 Spring
16 Bypass valve
14 17 Spring
18 O-ring
19 Bolt
20 Strainer
21 Retaining ring
1 22 Air breather
23 Sight gauge

23

18

7 12

19
3

5
78096WE22

6-37
2) RETURN OIL FILTER BYPASS VALVE
(1) When the filter is clogged
Bypass valve (1) is opened and the oil
1
returns directly to the tank without
passing through the filter.
·Bypass valve set pressure : 1.36 kg/cm2
(19.3 psi)

From MCV
770-3ATM (6-33)

6-38
3) AIR BREATHER
The air breather is equipped with the
capacity to perform three functions
simultaneously-as an air filter, breathing
valve, and as a lubrication opening.
(1) Preventing negative pressure inside the
tank
The tank is a pressurized sealed type, so
negative pressure is formed inside the
hydraulic tank when the oil level drops
during operations. When this happens,
the difference in pressure between the
tank and the outside atmospheric
pressure opens the poppet in the
breather, and air from the outside is let
into the tank or prevent negative pressure.
(2) Preventing excessive pressure inside
the tank
When the hydraulic cylinder is being
used, the oil level in the hydraulic system
increases and as temperature rises. If
the hydraulic pressure rises above the set
pressure, breather is actuated to release
the hydraulic pressure inside the tank. 78096MI26

6-39
10. ACCUMULATOR
The accumulator is installed at the safety
valve. When the boom is left the raised
position, and the control levers are operated
with the engine stopped the pressure of the
compressed nitrogen gas inside the
accumulator sends pilot pressure to the
control valve to actuate it and allow the boom
1
and bucket to come down under their own 2
weight.
3
Type of gas Nitrogen gas (N2)
Volume of gas 0.75ℓ(0.2 U.S.gal)
Charging pressure of gas 16 kg/cm2 (228 psi)
Max actuating pressure 128 kg/m2 (1820 psi)
1 Diaphragm
2 Steel pressure vessel
3 Closure button
7803AWE56

6-40
GROUP 2 OPERATIONAL CHECKS AND TROUBLESHOOTING

1. OPERATIONAL CHECKS
This procedure is designed so the mechanic can make a quick check of the system using a minimum
amount of diagnostic equipment. If you need additional information, read structure and function,
Group 1.
A location will be required which is level and has adequate space to complete the checks.
The engine and all other major components must be at operating temperature for some checks.
Locate system check in the left column and read completely, following the sequence from left to right.
Read each check completely before performing.
At the end of each check, if no problem is found (OK), that check is complete or an additional check is
needed. If problem is indicated (NOT OK), you will be given repair required and group location.
If verification is needed, you will be given next best source of information:

ÂChapter 2 : Troubleshooting


ÂGroup 3 : Tests and adjustments

6-41
※Hydraulic oil must be at operating temperature for these checks (refer to page 6-56).

Item Description Service action

Hydraulic system warm-up Hold a hydraulic function over OK
procedure relief to heat oil. (don't keep relief Check completed.
condition over 5 seconds at a time)
Run engine at high idle.
Refer to page 6-51. Periodically cycle all hydraulic
functions to distribute warm oil.
Repeat procedure until oil is at
operating temperature.
FEEL : Hydraulic reservoir must be
uncomfortable to hold your hand
against.
(approximately 40 ~50˚C)
Hydraulic pump With bucket flat on ground, actuate OK
performance check boom raise. Time how long it takes Check completed.
to raise boom to full height.
Heat hydraulic oil to NOT OK
operating temperature. LOOK : Boom must raise to full Go to priority valve (in flow
Run engine at high idle. height in less than 7 seconds. amplifier) high pressure
check at page 5-31.
IF OK
Do steering system
leakage check at page
5-30.
IF OK
Do main hydraulic pump
flow test at page 6-57.
Control valve lift check With bucket partially dumped, OK
Run machine at low idle. lower boom to raise front of Check complete.
machine.
NOT OK
Slowly move boom control lever Repair lift checks in loader
( R C V l eve r ) t o b o o m l owe r control valve.
position.
Slowly move bucket control lever
to bucket dump position.
LOOK : Boom must not raise
before moving down.
Bucket must not rollback before
dumping.

6-42
 Item Description Service action
Bucket rollback circuit relief Position bucket at a 45˚ angle OK
valve check against an immovable object. Check complete.
Engage transmission in 3rd speed NOT OK
forward. Replace boom lower
check valve.
LOOK : Bucket angle must not
change.
Bucket dump circuit relief Raise front of machine which OK
valve low pressure check bucket at 45˚ angle. Go to next check.
Backdrag with bucket while NOT OK
observing bucket angle. Do loader system and
circuit relief valve test at
LOOK : Bucket must not rollback
page 6-57.
Pilot control valve float With the bucket partially dumped, OK
check lower boom to raise front of Check complete.
machine.
Run engine at low idle. NOT OK
Push control lever to the float
Do pilot control valve
detent position and release lever.
pressure test in group 3.
LOOK : Front of machine lower to
the ground and valve must remain
in float position when lever is
released.

Boom cylinder and S e t t h e b o o m a n d b u c k e t OK

bucket cylinder drift horizontal, then stop the engine. Check complete.
check
S t o p t h e e n g i n e, wa i t fo r 5 NOT OK
Heat hydraulic oil to minutes, then start measuring. Go to next check.
operating temperature. B
Measure the amount the lift and
dump cylinder rods retract during
A 15 minutes. (unloaded bucket)
A : Retraction of boom cylinder
rod
B : Retraction of bucket cylinder
rod

B
Boom cylinder must drift less than
20 mm

A Bucket cylinder must drift less than

15 mm

6-43
 Item Description Service action
Boom cylinder leakage Dump bucket until teeth or cutting OK
check edge is per pendicular to the Drift is approximately the
ground. same between first and
Heat hydraulic oil to
second measurement.
operating temperature. Raise boom until cutting edge is
about 1 m (3 ft) above ground.
Repair loader control valve
Stop engine. Measure drift from or circuit relief valve.
tooth or cutting edge to ground for
1 minute. NOT OK
If drift is considerably less
Wait 10 minutes.
on second measurement,
Measure drift from tooth or cutting repair cylinder.
edge to ground for 1 minute.
LOOK : Compare the drift rate
between the first measurement
and the second measurement.
Bucket cylinder leakage Raise bucket about 1 m (3 ft) off OK
check ground with bucket level. Drift is approximately the
same between first and
Heat hydraulic oil to Stop engine. Place a support
second measurement.
operating temperature. under boom.
Measure drift from tooth or cutting Repair loader control valve
edge to ground for 1 minute. or circuit relief valve at
page 6-57.
Wait 10 minutes.
Measure drift from tooth or cutting NOT OK
edge to ground for 1 minute. Drift is considerably less
on second measurement.
LOOK : Compare the drift rates
between the first measurement
Repair cylinder.
and the second measurement.
Check valve of safety Put bucket level and position about OK
valve leakage check 1.2 m (4 ft) above ground. Check complete.
Heat hydraulic oil to Place a piece of tape on cylinder
NOT OK
operating temperature. rod at least 51 mm (2 in) from rod
Check or replace safety
guide.
valve.
Run engine at low idle in safety-
release position.
LOOK : Bucket must not drift up.
Pilot control valve Stop engine. Turn key switch to OK
OFF position. Check completed.
(RCV lever) check
Move control lever to all positions
NOT OK
and then release.
Repair pilot control valve.
LOOK : Lever must return to
neutral when released from all
positions.

6-44
 Item Description Service action
Bucket leveler Position bucket fully dumped just OK
(positioner) check above ground level. Check complete.
Run engine at low idle. Move control lever to bucket NOT OK
leveler detent position and release. Do bucket leveler checks.
LOOK : Bucket must rollback to
the level position and control lever
must return to neutral.
If bucket is in a rolled back position
when key is turned ON, control
lever must be returned to neutral
manually if placed in the bucket
leveler detent position.
After bucket is dumped once,
bucket leveler will work normally.
Boom height kickout Position bucket flat on ground. OK
check Check complete.
Move control lever to boom raise
Run engine at low idle. detent position and release. NOT OK
Do boom height kickout
LOOK : Boom must raise to the
check.
set height and stop.
Control lever must return to
neutral.
Cycle time check Function Operating condition. Maximum cycle time
H e a t h y d r a u l i c o i l t o Boom raise Bucket flat on ground to full height. 6.0sec
operating temperature.
Boom lower Full height to level ground. 3.7sec
Run engine at high idle.
Bucket dump Boom at full height. 1.4sec
Bucket rollback Boom at full height. 1.9sec
Steering [No. of Frame stop to frame stop. 4.3sec [4.3 turns]
turns]
OK
Check complete.
NOT OK
Go to slow hydraulic
functions in group 2.

6-45
※MEASURING BOOM AND BUCKET CYCLE TIME
1) MEASUREMENT CONDITION
ÂCoolant temperature : Inside operating range
ÂSteering position : Neutral
ÂHydraulic temperature : 40~50˚C
ÂBucket : Unloaded
ÂEngine speed : High idling

2) MEASURING TOOL
 Stop watch (1EA)

3) MEASURING PROCEDURE
(1) LIFTING TIME OF BOOM Lifting time of boom
Set the bucket near the maximum tilt back
position and at the lowest position on the
ground. Raise the bucket and measure
the time taken for bucket to reach the
maximum height of the boom.

78096WE25

(2) LOWERING TIME OF BOOM

Set the bucket horizontal with the boom at Lowering time of boom
the maximum height, lower the bucket and
measure the taken for the bucket to reach
the lowest position on the ground.

78096WE26

(3) DUMPING TIME OF BUCKET

Raise the boom to the maximum height Dumping time of bucket
and measure the time taken for the bucket Rollback time of bucket
to move from the maximum tilt back
position to the maximum dump position
(4) ROLL BACK TIME OF BUCKET
Raise the boom to the maximum height
and measure the time taken for the bucket
to reach the maximum tilt back position. 78096WE27

6-46
2. TROUBLESHOOTING
ö Diagnose malfunction charts are arranged from most probable and simplest to verify, to least
likely, more difficult to verify. Remember the following steps when troubleshooting a problem :

Step 1. Operational check out procedure (see section 1)

Step 2. Operational checks (see group 2)
Step 3. Troubleshooting
Step 4. Tests and adjustments (see group 3)
Problem Cause Remedy
Noisy hydraulic pump Low oil supply or wrong viscosity. Fill reservoir with recommended oil.
Plugged or pinched suction line. Clean or replace line.
Air in oil. Check for foamy oil. Tighten
connections.
Replace O-rings and or lines.
Plugged suction strainer. Inspect and clean strainer in reservoir.
Loose or missing hydraulic line clamps. Tighten or replace clamps.
Hydraulic lines in contract with frame. Inspect and repair.
Worn or damaged pump. Do hydraulic pump performance check
in group 2. Do hydraulic pump flow test
in group 3.
No or Slow hydraulic Failed or worn hydraulic pump. Do performance check.
functions
Cold oil. Warm oil up.
Slow engine speed. Adjust engine speed.
Check high idle speed.
Suction line air leak. Check for foamy oil.
Low oil supply. Add recommended oil.
Wrong oil viscosity. Use recommended oil.
Oil leaking past cylinders or control Check cylinder drift in group 2.
valve.
Blocked or damaged line. Inspect lines.

Faulty pilot control valve (RCV). Do pilot control valve (RCV) pressure
test in group 3.
Binding loader control valve (MCV) Inspect valve.
spool.
Faulty flow amplifier. Check priority valve, orifice of flow
amplifier specification.

6-47
 Problem Cause Remedy
No steering or hydraulic Low oil level. Add recommended oil.
function
Failed hydraulic pump. Remove and inspect return filter for
metal pump particles.
No hydraulic functions Failed hydraulic pump. Remove and inspect return filter for
steering normal metal pump particles, or replace the
pump.
Failed line filter. Remove and inspect line filter for RCV.
Faulty safety valve. Safety valve leakage test or ON, OFF
function test.
Stuck open port relief valve. Replace relief valve.
Boom float function Low pilot control pressure. Do pressure reducing valve pressure
does not work test in group 3.
Faulty pilot control valve (RCV). Replace relief valve.
Loader control valve (MCV) spool Do pressure reducing valve pressure
binding in bore. test in group 3.
One hydraulic function Faulty pilot control valve (RCV). Do pilot control valve pressure test.
does not work. Inspect and repair valve.
Stuck open port relief valve. Replace relief valve.
Oil leaking past cylinder packings. Do boom and bucket cylinder leakage
test in group 3.
Blockage in oil lines or valve. Inspect lines for damage.
Disconnect and inspect lines for internal
blockage.
Loader control valve (MCV) spool stuck Inspect and repair valve.
in bore.
Low hydraulic power Leakage within work circuit. Do cylinder drift check in group 2.
Low system relief valve (main relief Do loader system and port relief valve
valve) setting. pressure test in group 3.
Low port relief valve setting. Do loader system and port relief valve
pressure test in group 3.

Leaking system relief valve. Remove and inspect valve.

Worn hydraulic pump. Do hydraulic pump performance check
in group 2.
Faulty pilot control valve (RCV). Do pilot control valve pressure test in
group 3.

6-48
 Problem Cause Remedy
Function drifts down Leaking cylinders. Do cylinder leakage checks in group 3.
Leaking seals in circuit relief valve (port Inspect seals. Replace relief valve.
relief valve) or valve stuck open.
Leaking loader control valve (MCV). Repair or replace valve section.
Boom drifts up Leakage in boom down spool. Remove and inspect boom down spool.
Boom down does not Safety valve not operated. Operate valve.
work (engine off)
Stuck pilot control valve. Inspect.
Faulty line filter. Remove and inspect filter.
Accumulation not operated. Inspect.
MCV spool stuck. Inspect and repair valve.
Oil overheats Low oil viscosity in hot weather. Use recommended oil.
Excessive load. Reduce load.
Holding hydraulic system over relief. Reduce load.
Leakage in work circuit. Do boom and bucket cylinder leakage
test in group 3.
Plugged fins in oil cooler. Inspect and clean oil cooler.
Internally plugged oil cooler. Do hydraulic oil cooler restriction test.
Incorrect system or circuit relief valve Do loader system and circuit relief valve
setting. pressure test in group 3.
Restriction in oil lines or loader control Inspect for dented or kinked lines.
valve (MCV).
Malfunctioning steering valve. Do hydraulic system restriction test in
group 3.
Leaking system main relief valve. Do hydraulic system restriction test in
group 3.
Remove and inspect valve and seals.
Worn hydraulic pump (internal leakage). Do hydraulic pump performance check
in group 2.
Function drops before Stuck open lift check valve. Do control valve lift check in group 2.
raising when valve is
activated

6-49
 Problem Cause Remedy
Hydraulic oil foams Low oil level. Add recommended oil.
Wrong oil. Change to recommended oil.
Water in oil. Change oil.
Loose or faulty suction lines (air leak in Tighten or install new lines.
system).
Remote control valve Leaking plunger seals. Remove, inspect and replace plunger
(RCV) leaking seals.

ö Followings are general precautions for the hydraulic system and equipment.
1) Every structure has its limit of strength and durability. The relief valve is installed to limit the
pressure on the hydraulic equipment and protect various parts of the wheel loader from possible
damage. Therefore, never change the preset pressure of the relief valve unless absolutely
necessary.
2) Since the hydraulic equipment is built with precision, the presence of only the slightest amount of
dust and / or other particles in the hydraulic circuit might cause wear and/or damage, resulting in
unstable functions and/or damage, resulting in unstable functions and/or unexpected accidents.
Therefore, always keep hydraulic oil clean. Periodically, check the filter in the return circuit and
replace the element as necessary.
3) Extract about 200cc of hydraulic oil from the tank as a sample every 6 months. If possible, have it
analyzed by a specialist to confirm that the oil can still be used. Never extract the oil for sampling
until the oil temperature has become the normal operating temperature. Since the replacement
period varies depending on operating conditions, refer to Operator's Manual and change oil.
4) Should the equipment get damaged due to the presence of metal particles and/or foreign matter in
the circuit drain out the hydraulic oil and carry out flushing. Also, replace the filter element and
clean the hydraulic tank. Change the hydraulic oil entirely.
5) When checking the filter, if found metal particles in the element, drain out the hydraulic oil entirely,
flush the whole circuit, and then fill with new oil. The presence of metal particles may indicate
internal damage to the equipment. In such a case, check carefully before flushing, and repair or
replace as required.
6) To add and/or change the hydraulic oil, always use recommended oil. (Refer to the list of
recommended oils and lubricants at page 1-24, Recommended lubricants
lubricants..) Never mix oil of
different makes of kinds.
7) To change the hydraulic oil, use a clean vessel and funnel for pouring it into the tank. Never use
cloth because it might cause the presence of lint in the circuit.
8) When removing the hydraulic equipment, be sure to put plugs or caps on hoses, tube lines and
ports. Also, enter mating marks for later identification.

6-50
9) Disassemble and/or assemble the hydraulic equipment only in a clean place free of dust. When
disassembling, be careful about the interchangeability of parts, and clean the disassembled parts
with pure and clean mineral cleansing oil. Clean the internal passages as well. After the parts
have dried, wipe them off with a clean lint-free cloth.
10) When overhauling the hydraulic equipment replace all O-rings, backup rings, etc. with new ones.
Assemble O-rings with grease or vaseline applied.
11) After installing the equipment, add more hydraulic oil to make up for that lost during disassembly.
12) Tighten joints correctly. Loose joints will cause the hydraulic oil to leak. If the oil leaks, the tank oil
level drops and air gets sucked in, so the pump will break down. Also loose joints in suction lines
will take air in and might cause abnormal noise, malfunction or damage to pumps.

6-51
GROUP 3 TESTS AND ADJUSTMENTS

1. HYDRAULIC OIL CLEAN UP PROCEDURE USING PORTABLE FILTER CADDY

※ Service equipment and tool
·Portable filter caddy
·Two 4000 mm × 1in 100R1 Hoses
·Quick disconnect fittings.
·Discharge wand
·Various size fittings.
※ Brake system uses oil from hydraulic oil
tank. Flush all lines in the brake, pilot,
steering system and cut off system.
Disassemble and clean major
components for brake and steering
system. Remove and clean pilot caps
from main control valve.
Brake and steering components may fail
if brake and steering system is not
cleaned after hydraulic oil tank
contamination.
1) If hydraulic system is contaminated due to
a major component failure, remove and
disassemble steering cylinders to clean
debris from cylinders.
2) Install a new return filter element. Inspect
filter housing before installing new element.
※ For a failure that creates a lot of debris,
remove access cover from hydraulic oil
tank. Drain and clean hydraulic oil tank of
fill the specified oil to hydraulic oil tank
through upper cover.
3) To minimize oil loss, pull a vacuum in
hydraulic oil tank using a vacuum pump.
Connect filter caddy suction line to drain
port at bottom of hydraulic oil tank using
connector. Check to be sure debris has not
closed drain port.
4) Put filter caddy discharge line into hydraulic
oil tank filler hole so end is as far away from
drain port as possible to obtain a thorough
cleaning of oil.

6-52
5) Start the filter caddy. Check to be sure oil is
flowing through the filters.
Operate filter caddy approximately 10
minutes so oil in hydraulic oil tank is
circulated through filter a minimum of four
times.
※ Hydraulic oil tank capacity : 234ℓ(61.8
U.S. gal)
Leave filter caddy operation for the next
steps.
6) Start the engine and run it at high idle.
※ For the most effective results, cleaning
procedure must start with the smallest
capacity circuit then proceed to the next
largest capacity circuit.
7) Operate all functions, one at a time,
through a complete cycle in the following
order: Clam, steering, bucket, and boom.
Also include all auxiliary hydraulic functions.
Repeat procedure until the total system
capacity has circulated through filter caddy
seven times, approximately 30 minutes.
Each function must go through a minimum
of three complete cycles for a through
cleaning for oil.
※ Filtering time for machines with auxiliary
hydraulic functions must be increased
because system capacity is larger.
8) Stop the engine. Remove the filter caddy.
9) Install a new return filter element.
10) Check oil level in reservoir; Add oil if
necessary.

6-53
2. BOOM HEIGHT KICKOUT ADJUSTMENT
The bucket can be adjusted to a height
desired by using the boom kick-out device.
Park the machine on level ground and
bl o ck t h e t i r e s t o p r eve n t s u d d e n
movement of the machine.
Press the parking brake switch.
Fix the front and rear frames by using the
safety lock bar.
D o n o t wo r k u n d e r n e a t h t h e wo r k
equipment.

1) ADJUSTMENT OF THE BOOM KICKOUT

(1) Lift kickout position Top
Bottom
To set the lift kickout, raise the bucket to the
desired position above the midway point. Then
depress the top of switch for 2~3 seconds. The
boom will return to the programmed position
when the raise detent is activated and the boom Boom kickout & bucket leveler
set switch
is below the kickout position.
(2) Lower kickout position
(2 Boom pivot pin
Bucket pivot pin
To set the lower kickout, lower the bucket to the
desired position below the midway point. Then
depress the top of switch for 2~3 seconds. The
boom will return to the programmed position Midway
point
when the float detent is activated and the boom
is at least a foot above the kickout position.
(3) Bucket leveler position
(3
To set the bucket leveler, roll back the bucket to Detent
Neutral
the desired position. Then depress the bottom of position
switch for 2~3 seconds. The bucket will return to
the programmed position when the roll back
detent is activated and the bucket is below the
leveler position. 75794OP28

6-54
3. TEST TOOLS
1) CLAMP-ON ELECTRONIC TACHOMETER
INSTALLATION
·Service equipment and tools
B
Tachometer
A : Clamp on tachometer.
Remove paint using emery cloth and
C
connect to a straight section of injection
line within 100 mm (4 in) of pump. Finger
Tighten only-do not over tighten. D
B : Black clip ( - ). Connect to main frame.
C : Red clip (+). Connect to transducer. A
D : Tachometer readout. Install cable.
75795SE32

2) DIGITAL THERMOMETER INSTALLATION

·Service equipment and tools
Digital thermometer
A : Temperature probe.
Fasten to a bare metal line using a tie A
band. Wrap with shop towel. C
B : Cable. B
C : Digital thermometer.

75795SE33

3) DISPLAY MONITOR TACHOMETER

The display monitor tachometer is accurate
enough for test work.

75795SE35

6-55
4. HYDRAULIC OIL WARM UP PROCEDURE
1) Install temperature reader (see temperature
reader installation procedure in this group).

2) Run engine at high idle.

3) Hold a hydraulic function over relief to heat
the oil.

4) Periodically cycle all hydraulic functions to

distribute warm oil.

5) Heat oil to test specification (approx. 45˚C).

※ Ride control system (option)

Attention Ride control valve
1) Before carrying out any maintenance work
the accumulators must be unloaded (zero
pressure). AB

2) For this, unscrew the plug (A) then rotate the

drain screw (B), located under the plug (A), 2
turns anti-clockwise with 3 mm L-wrench.
3) The lifting system must firstly be secured
against lowering. 7707AWE21

4) After carrying out maintenance work, screw

the plug (A) and drain screw (B).
·Tightening torque
A : 0.51 kgf·m (3.69 lbf·ft)
B : 0.36 kgf·m (2.58 lbf·ft)

6-56
5. MAIN HYDRAULIC PUMP FLOW TEST
· SPECIFICATION
Oil temperature 45±5˚C (113±9˚F) HYD tank
Engine speed 2000±25 rpm MCV
Test pressure 280±5 bar (3980 psi)
Maximum pump flow 420ℓ/min (111 gpm) P
T

· FLOW METER, GAUGE AND TOOL

Gauge 0~35 MPa (0~350 bar, 0~5000 psi)
Temperature reader
1) Make test connections.
2) Install temperature reader.
Flow meter
(see temperature reader installation
procedure in this group) Flow amplifier
EF port
3) Heat hydraulic oil to specifications.
(see hydraulic oil warm up procedure in this
group)
Main pump
4) Run engine at test specifications.
5) Close flow meter loading valve to increase
pressure to test specifications.
6) Read flow meter.
7) If flow is below specifications, check suction
line and suction pressure for abnormality
before removing pump. 78096WE29

6-57
6. LOADER
L ADER SYSTEM AND PORT RELIEF
VALVE PRESSURE TEST
· SPECIFICATION
Oil temperature (40~50˚C)
Relief valve Engine speed Relief pressure

280±5 kg/cm2
System (M) Low
(3980±70 psi)
Boom 340±10 kg/cm2
Low
raise (U) (4840±140 psi)
Bucket 340±10 kg/cm2
Low
rollback (R) (4840±140 psi) M
Bucket 310±10 kg/cm2 LS relief valve
Low
dump (D) (4410±140 psi) U
R
· Gauge and tool
Gauge 0~35 MPa (0~350 bar, 0~5000 psi)
M : System (main) relief valve
D
R : Bucket rollback relief
D : Bucket dump relief
U : Boom raise relief
1) Install fitting and pressure gauge to test
port in pump delivery line. MCV

2) Install temperature reader.

(see temperature reader installation P
T
procedure in this group)
3) Heat hydraulic oil to specifications. Pressure measure
positon : MCV P port
(see hydraulic oil warm up procedure in this
group)
4) To check the system relief (M), run engine
at low idle. Lower boom to bottomed
position.
Slowly activate boom down function while
watching pressure gauge. If pressure is not
to specification, loosen lock nut on system
relief valve (M) and adjust to specification. 78096WE30

6-58
※ Do not adjust the system relief valve
above 280 kg/cm2 (3980 psi). Damage to
the pump will result from excessive
pressure settings.

6-59
7. HYDRAULIC SYSTEM RESTRICTION TEST
· SPECIFICATION
Oil temperature 45±5˚C (113±9˚F)
Engine speed High idle
Maximum pressure 4.5 MPa (45 bar, 640 psi) at
flow amplifier.
Maximum pressure at main control valve
1 MPa (10 bar, 145 psi)
· GAUGE AND TOOL
EF port
Gauge 0~7 MPa (0~70 bar, 0~1000 psi) 2EA
This test will check for restrictions in the hydraulic
system which can cause overheating of hydraulic
oil.
1) Install temperature reader.
(see temperature reader installation procedure in
this group) Flow amplifier

2) Heat hydraulic oil to specifications.

(see hydraulic oil warm up procedure in this
group)
3) Connect fitting and gauge to steering valve.
4) Connect fitting and gauge to main control valve.
Do not operate steering or loader functions or P
T
test gauge may be damaged.
MCV
5) Run engine at specification and read pressure
gauges.
If pressure is more than specification at the
loader control valve, check for a kinked, dented
or obstructed hydraulic line. Check loader control
valve for a binding spool.
If pressure is more than specification at the
steering unit, inspect neutral condition of the
steering unit and flow amplifier for a stuck spool.
Make sure orifice plugs are installed in ends of
priority valve spool.
Check for plugged orifice in priority valve and
dynamic signal orifice on flow amplifier body.
78096WE31

6-60
8. LOADER CYLINDER DRIFT TEST
· SPECIFICATION
Oil temperature 45±5˚C (113±9˚F)
Boom horizontal
Bucket horizontal B
Bucket unloaded
Item Standard value
Retraction of boom
20 mm A
cylinder rod
Retraction of bucket
15 mm
cylinder rod B
· GAUGE AND TOOL
Stop watch
Temperature reader A : Retraction of bucket cylinder rod
Put the safety lock lever in the lock B : Retraction of boom cylinder rod
position.
Do not go under the work equipment.
1) Set the boom and bucket horizontal, then
stop the engine.
2) Stop the engine, wait for 5 minutes, then
start measuring.
3) Measure the amount the boom and bucket
cylinder rods retract during 15 minutes.
7577AWE31

6-61
9. BOOM AND BUCKET CYLINDER LEAKAGE TEST
· SPECIFICATION
Oil temperature 45±5˚C (113±9˚F)
Engine speed Low idle
Maximum leakage 15 mℓ/min (1/2 oz/min)
· GAUGE AND TOOL
Temperature reader
Stop watch
Measuring container
1) Fasten temperature sensor to head end
port of cylinder to be tested. Cover sensor
with a shop towel.
2) Heat hydraulic oil to specifications (see
hydraulic oil warm up procedure in this
group).
Never work under raised equipment
unless it is supported with a hoist or
support stands.
3) Full extend the cylinder to be tested. If
testing the boom cylinders, restrain boom in
the fully raised position using a hoist or a
stand.
※ Check cylinders for leakage in the fully
extended position only. In the retracted
position contacts the end of the cylinder
and seals off piston seal leakage.
4) Remove and plug cylinder rod end hose or
line.
5) Run engine at slow idle. Activate control
lever to extend cylinder for 1 minute over
relief while measuring leakage for open
port.
If leakage is within specification, excessive
cylinder drift is caused by leakage in the
(770-3ATM) 6-56
loader control valve or circuit relief valve.

6-62
10. PILOT CONTROL VALVE PRESSURE
PRESSURE TEST
· SPECIFICATION
Oil temperature 45±5˚C (113±9˚F)
Engine speed Low idle
Begin metering 1/4" of lever travel
Pressure in detent :
Boom float detent 1.9 MPa (24 bar)
Pressure at feel position :
Boom power down 22~24bar
Boom raise 22~24bar
Bucket rollback 22~24bar
Bucket dump 22~24bar
· GAUGE AND TOOL
Gauge 0~7 MPa (0~70 bar, 0~1000 psi)
As the control lever is moved from neutral,
the pilot pressure will suddenly jump up to
approximately 6.5bar at 1/4in. travel. The
pressure should then increase smoothly to P

the specification at the FEEL position (or

3/4 lever travel), and then jump up about
Safety valve
30bar as the lever is moved into detent.
This test will determine if adequate pilot
pressure is available to move the loader
control valve spools.
※ The FEEL position is when lever is
moved to feel the ramp of the detent
before lever passes into detent position.
1) Lower boom to ground.
2) Connect gauge to the pilot pressure port of
function to be checked.
3) Install temperature reader (see temperature
reader installation procedure in this group).
4) Heat hydraulic oil to specification (see
hydraulic oil warm up procedure in this
78096WE32
group).

6-63
5) Run engine at specification. Activate
function to be checked and record pressure
reading.
※ If boom raise or bucket rollback FEEL
positions are not operation due to boom
or bucket position, plug boom float detent
wires into bucket leveler solenoid or
boom height kickout solenoid. This will
provide a feel position on the control
lever.

6-64
11. CYCLE TIME TEST
· SPECIFICATION
Oil temperature 45±5˚C (113±9˚F)
Engine speed High idle
Function Operating conditions Maximum cycle time (seconds)
Boom raise Bucket flat on ground to full height 6.0
Boom lower (float) Full height to ground level 3.7
Bucket dump Boom at full height 1.4
Bucket rollback Boom at full height 1.9
Steering (number of turns) Frame stop to stop 4.3 (4.3)

Hydraulic pump performance cycle time.

Function Operating conditions Maximum cycle time (seconds)
Bucket flat on ground to full height
Boom raise 8.0
while holding steering over relief

6-65
12. HYDRAULIC OIL FILTER INSPECTION
PROCEDURE
1) Lower the bucket to the ground, stop the
engine, move the control lever back and
forth several times, and clean all over the
upper surface of the hydraulic oil tank.
2) Remove the bolts and take out the filter
case cover and O-ring.
Cover
3) Remove the spring and bypass valve. O-ring
4) Remove the filter element from the tank. Spring
By-pass valve
5) Check the element and the filter case
bottom for debris. Excessive amounts of Return filter
brass and steel particles can indicate a
failed hydraulic pump or a pump failure in
process. A rubber type of material can
indicated cylinder packing or other packing
failure.
※ The hydraulic oil filter in the filter case of
the hydraulic oil tank should be replaced
every 250 operating hours or more often.
When the filter element is replaced,
please keep as follows.
(1) Clean the inside of the filter case.
(2) Place new element in the proper positions
inside the filter case.
(3) Install the bypass valve and spring.
Make sure the element stand upright, and
check for complete contact of the element
bottom with the filter case bottom.
(4) Install the O-ring and filter case covers.
Tighten them with bolt. Replace the
78096MI24
O-ring with new one if damaged.

6-66
GROUP 4 DISASSEMBLY AND ASSEMBLY

1. MAIN PUMP (STEERING PUMP, LOADER PUMP)

1) STRUCTURE
27
23

6,31 2

51

33 16
12

1-2

1-1

30

7
17
22

15
20
25 78096WE11

1 Rotary group 8 Drive shaft 23 O-ring

1-1 High speed rotary group 12 Adjustment shim 25 V-ring
1-2 Control plate 15 Taper roller bearing 27 Socket screw
2 Adjusting piece 16 Taper roller bearing 30 Locking screw
5 Pump housing 17 Bearing liner 31 Double break-off pin
6 Port plate 20 Shaft seal ring 33 Cylinder pin
7 Swash plate 22 O-ring 51 Control valve

6-67
2) GENERAL REPAIR GUIDELINES
ö Observe the following guidelines when
carrying out repairs on hydraulic pumps.
(1) Close off all openings of the hydraulic unit.
(2) Replace all of the seals.
Use only original spare parts.
(3) Check all sealing and sliding surfaces for
wear.
ö Re-work of the sliding surfaces by using,
for example abrasive paper, can damage
the surface.
(4) Fill the hydraulic pump with hydraulic oil
before commissioning.

3) SEALING THE DRIVE SHAFT

(1) Protect the drive shaft. 1
Remove the circlip.
Remove the shaft seal.
1 Circlip 2 Shaft seal

2
75796WE60

(2) Change the shaft seal and check its

sliding surface (drive shaft) and housing,
grease the sealing ring.

75796WE58

(3) Assemble the sealing ring, fitting tool

holds the correct position of the sealing
ring in the pump housing.
Assemble the circlip in the correct
position.

75796WE59

6-68
4) SEALING / CLEANING THE CONTROL
A
VALVE
(1) Disassemble the control valve.
ö Measure dimension A and note down.
Check sealing surface (1).
A

75796WE62

5) DISASSEMBLE THE PUMP

(1) Remove the control valve.

75796WE63

(2) Mark the location of the connection plate

on the housing.

75796WE64

6-69
(3) Remove the connection plate fixing bolts
and the connection plate.
ö Distributor plate and adjustment piston
can drop down.

75796WE65

(4) Remove distributor plate.

Take note of the orientation.
ö Remove bearing with withdrawal tool.
Do not damage the sealing surface.

75796WE66

(5) Remove the rotary group in a horizontal

position.

75796WE67

6-70
(6) Remove swash plate and bearing shells.

75796WE68

(7) Remove the circlip and the shaft seal.

75796WE69

(8) Remove the drive shaft through rear side.

75796WE70

(9) Pre-tension the spring (1) using a suitable

1
device. 2
Remove circlip (2).
Remove spring (1) and pressure pins (3).

3 75796WE72

6-71
(10) Use bearing puller to remove outer
bearing race of front bearing out of
housing press seat.

75796WE74

(11) Remove the control plate.

75796WE75

(12) Use bearing puller to remove outer

bearing race of rear bearing - press seat.

75796WE76

(13) Disassemble the guide of control piston

(Mounting position: pilot valve side).

75796WE77

6-72
(14) Disassemble the guide of the opposite
piston.

75796WE78

6) INSPECT HINTS
(1) Renew all bearings.

75796WE79

(2) Check :
1 Wear on splines, rust 1
6
5
2 Drive shaft seal wear grooves
4
3 Bearing seat
2 3
4 Splines for cylinder drive 1
5 Bearing seat

75796WE80

(3) Check :
Sliding surface free of grooves.

75796WE81

6-73
(4) Check :
Bearing surfaces.

75796WE82

(5) Check :
That the retaining plate is free of grooves
and that there is no wear in the slipper
pad area.

75796WE83

(6) Check :
Check to see that there are no scratches 1
or metal deposits on the sliding surface
(1) and that there is no axial play (2)
(Pistons must only be replaced as a set).

2
2

75796WE84

(7) Check :
1 Cylinder bores 2 1
2 Splines

75796WE85

6-74
(8) Free of grooves, no signs of wear.

75796WE86

(9) Check :
Cylinder sliding surface free of grooves,
no wear, no embedded foreign particles.
That there are no scratches on the control
plate. (Only replace them as a set).

75796WE87

(10) Check : L1
M o u n t i n g s u r fa c e - c o n t r o l p l a t e
undamaged.

75796WE88

(11) Check :
Check running conditions of the control
piston.

75796WE89

6-75
(12) Check :
Check running conditions of the opposite
piston.

75796WE90

7) ADJUSTMENT OF TAPER ROLLER 0~0.05mm

BEARING SET
(1) Cast iron housing must have initial
tension of the bearings: 0~0,05 mm, grind
position A if necessary.

Position A

75796WE91

8) PUMP ASSEMBLY
(1) Fit the seal into the housing.
Fit the circlip.

75796WE92

(2) Fit the drive with bearing from rear end.

ö Do not touch seal lip with edge of keyway
or spline.

75796WE93

6-76
(3) Fit pressure pins using an assembly aid.

75796WE94

(4) Pre-tension the spring using a suitable

device.

75796WE95

(5) Assemble piston with retaining plate.

ö Oil piston and slipper pad.

75796WE97

6-77
(6) Fit rotary group.
ö Hold the piston by using an O-ring.
Fit O-ring (1).

75796WE98

(7) Fit bearing (1) in connection plate.

Fit cyilindrical pin (2).
Fit O-rings (3) 4 pieces.
5
Fit adjustment spool (4) and guide piston
(4a).
Fit distributor plate (5) (direction of
rotation dependent)
ö Assembly. 4
1
Hold the components in place with
grease. 2
3
4a

75796WE99

6-78
(8) Fit distributor plate.
ö Assembly aid : Grease

75796WE100

(9) For clockwise rotation pumps the

distributor plate is off-set by 4˚ to the right
from the centre position.
(Clockwise and anti-clockwise rotation
distributor plates are not identical).

75796WE101

(10) Fit connection plate and control valve.

75796WE63

6-79
2. MAIN CONTROL VALVE
1) STRUCTURE (1/2)

62
63 60

61
36 38

37
38 79

35

50
80

50

79
74
38

37
38
36
80
35

65

33

33 32
11
79
31

30

86
102 71

84
165
74

79
85

78096WE13

11 Housing 38 O-ring 74 Compensator valve

30 O-ring 50 Housing 79 Pressure valve
31 O-ring 60 Plate 80 Plug screw
32 O-ring 61 Stud 84 Flow regulator
33 O-ring 62 Hexagon nut 85 Precharge valve
35 O-ring 63 Washer 86 Pressure reducing valve
36 O-ring 65 Sandwich plate 102 Locking screw
37 O-ring 71 Shuttle valve 165 Pressure relief valve

6-80
 STRUCTURE (2/2)

23
21

20

12 44
96
90
91
39 43
23
21
90
91
50 39
95 19
95

39 13
91 50 42
90
96 90 23
12 21
91
21 34 13
23
39
19
65

20

34
91
90
41
96
12
23
21 90
23 91
11
34
20

12
20
96 78096WE14

11 Housing 34 O-ring 65 Sandwich plate

12 Cover 39 O-ring 90 Compression spring
13 Cover 41 Spool 91 Spring retainer
19 Bolt 42 Spool 95 Spring retainer
20 Bolt 43 Spool 96 Spring retainer
21 Throttle check valve 44 Spool
23 Threaded steel pipe fitting 50 Housing

6-81
2) GENERAL PRECAUTIONS
(1) Clean room with no dust is recommended for maintenance. Because hydraulic components
are precision, and have minute clearance. Tool and wash-oil must be clean, too. Handle
them carefully.
(2) At removing control valve from the machine, wash around the piping port, and neither dust
nor water should go into inside with plugging. It is same at attaching the machine.
(3) Prepare the required parts by checking structure figure before assembly. There are parts
which are supplied with only sub-assembly part, so check the parts list before assembly.
3) PRECAUTIONS FOR DISASSEMBLY
(1) Handle the components carefully not to drop them or bump them with each other as they are
made with precision.
(2) Do not force the work by hitting or twisting as burred or damaged component may not be
assembled or result in oil leakage or low performance.
(3) When disassembled, tag the components for identification so that they can be reassembled
correctly.
(4) Once disassembled, O-ring and back-up rings are usually not to be used again.(Remove them
using a wire with its end made like a shoe-horn. Be careful not to damage the slot)
(5) If the components are left disassembled or half-disassembled, they may get rust from moisture or
dust. If the work has to be interrupted, take care to prevent rust and dust.
4) PRECAUTIONS FOR REASSEMBLY
(1) Take the same precautions as for disassembly.
(2) When assembling the components, remove any metal chips or foreign objects and check them
for any burrs or dents. Remove burrs and dents with oil-stone, if any.
(3) O-rings and back-up rings are to be replaced with new ones, as a rule.
(4) When installing O-rings and back-up rings, be careful not to damage them. (Apply a little amount
of grease for smoothness)
(5) Tighten the bolts and caps with specified torque.

6-82
5) DISASSEMBLY AND ASSEMBLY
(1) Spool
Η Loosen the bolt (2EA).
ÂTool : Wrench 5 mm
ÂTightening torque : 0.85 kgfÂm
(6.1 lbfÂft)

76096WE40

Θ Remove the cover, spring retainer, spring

and spool.

76096WE41

1 Spring
1
2 Spring ratainer
3 Spool
4 Cover
5 Bolt
2 3 4 5

76096WE42

(2) Compensator valve

ÂTool : Spanner 42 mm

76096WE43

6-83
 ÂTightening torque : 20.4 kgfÂm
(148 lbfÂft)

76096WE44

(3) Port relief valve

ÂTool : Spanner 30 mm

76096WE45

ÂTightening torque : 10.2 kgfÂm

(73.8 lbfÂft)

76096WE46

(4) Precharge valve

ÂTool : Spanner 32 mm

76096WE47

6-84
 ÂTightening torque : 6.1 kgfÂm
(44.3 lbfÂft)

76096WE48

(5) Shttle valve

ÂTool : Spanner 22 mm

76096WE49

ÂTightening torque : 3.6 kgfÂm

(25.8 lbfÂft)

76096WE50

6-85
3. REMOTE CONTROL VALVE
1) STRUCTURE

2
1

3-1
3-2
Locite 262
3-3

5
11-1
11-2 12-1
4,3,1 12-2
4 1
10 3 2
30
11-3 12-3
11-4 12-4
2
33 30
11-5
11-6
4,3,1 14 32
40
15

40
4 1
20-1 42
20 3 2

22
21
23 4 1

3 2
25

26

7707WE64

1 Handle 11-4 Cardan 22 Intermediary plunger kit

2 Push button 11-5 Armature 23 Intermediary plunger guide
3-1 Locking pin 11-6 Spring ring 25 Electric bracket
3-2 Bent lever 12-1 Counter nut 26 Bushing
3-3 Nut 12-2 Spring ring 30 Plunger kit
4 Rubber boot 12-3 Switch plate screw 32 Regulation unit
5 Locking nut 12-4 Press screw 33 Regulation unit
10 Cardan bracket 14 Shims (0.1, 0.2, 0.5 mm) 40 Return spring
11-1 Self-locking nut 15 Cardan 42 Prefeeling point kit
11-2 Washer 20 Flange
11-3 Washer 21 Solenoid

6-86
2) DISASSEMBLY AND ASSEMBLY
(1) PUSH BUTTON
ö The remote control valve does not need to be removed from the machine to perform this
operation.
Remove worn pushbutton using a small screwdriver.
The installation of new elements is performed without any special tools; the parts are simply
pressed into place.
(2) RUBBER BOOT
Η Remove the remote control valve from the machine or free the valve by unscrewing the 4 screws
fixing the plate in order to release the electrical cable.
ÂAssembly
Torque : 1.02 kgfÂm (7.4 lbfÂft)
Hold the remote control valve using a vice or a vice-grip wrench (clamp onto the body).
ö
The pilot unit does not need to be removed from the machine to release the cable. However, it is
recommended to lift the control unit by undoing the 4 fixing screws on the arm rest.
ö It is unnecessary to remove the units with no electrical functions.
Θ Lift and turn the boot inside out.
Ι
Remove the grommet (7) from its emplacement to free the cable.
Κ
Loosen the handle mounting nut (3-3) using a 19 mm open-end wrench.
ÂAssembly : torque 4.08 kgfÂm (29.5 lbfÂft)
Λ
Unscrew and remove the handle (1).
ÂAssembly
- Add loctite 262 onto the lever thread
- Torque : 4.08 kgfÂm (29.5 lbfÂft)
Μ
Replace the faulty rubber boot (4) with a new one.
Ν
Replace the handle (1) following the disassembly instructions in reverse order.
(3) HANDLE
Η Clamp the threaded section of the lever (3-2) in a vice fitted with V-shaped vice clamp.
Θ Remove the pin (3-1) using a 5mm pin driver.
Ι
Replace the lever (3-2) onto the new handle (1) and secure it with the pin (3-1) using a 5mm pin
driver.
ö Respect the position of the curved lever to ensure that the handle is correctly oriented as
indicated by the machine’s technical specifications.
Κ
Replace the nut (3-3) on the threaded section and replace the boot (4).

6-87
(4) DETENT CARDAN BRACKET KIT
ö Remove the 2 grommets (20-1) from the W

flange (20). V
ö Place centering sleeves V & W to avoid
damaging the cardan knuckles while
loosening the nuts.
ö Unscrew the locking nut (5) using a
23mm open-end wrench.
ÂAssembly : Torque 4.08Ü0.4 kgfÂm
(29.5Ü2.9 lbG·ft)
Before loosening the nuts
Η Unscrew the self-locking nut (11-1) using
a 13mm open-end wrench.
W
ÂAssembly
- Torque 1.02 kgfÂm (7.4 lbfÂft)
- Place centering sleeves (V-W) to avoid
damaging the cardan knuckles while
screwing the nuts. V
Θ Remove : - Friction washer (11-2)
- Friction washer (11-3)

- Cardan/armature assembly After removing the cardan bracket
7707WE65
(11-4 ~ 11-6)

(5) NON-DETENT PLUNGER KIT

Η
Unscrew the self-locking nut (12-1) using a 13 mm open-end wrench.
ÂReassembly : - Torque 1.02 kgfÂm (7.4 lbfÂft)
- Place centering sleeves (V-W) to avoid damaging the cardan knuckles while
screwing the nuts.
Θ
Undo the snap ring (12-2) using a flat-end screwdriver.
Ι
Remove the screw assembly (12-3, 12-4)
(6) CARDAN
Η
Remove the centering sleeves V & W.
Θ
Remove the cardan bracket (10) and the shims (14).
Ι
Unscrew the cardan (15) using a 17 mm open-end wrench.
ÂReassembly : - Ungrease the cardan threads
- Add loctite 262 onto the cardan threads (both end)
- Torque 4.08 kgfÂm (29.5lbfÂft)
(7) SOLENOID AND CONNECTOR
ö It is advised to mount the connector onto the solenoid cable once the remote control valve is
assembled.
Η
Remove the flange (20) and the electrical bracket (25),
Θ
Remove the protecting bushes (26) from the electrical bracket (25).
Ι Undo the solenoid (21) from the electric bracket (25).
Κ Replace the solenoid.
ö Clean the polar face using a piece of cloth and pay attention not to hit them.
Λ
Assembly : Place the solenoid cable in its emplacement on the electric bracket before fitting the
protection bushes.

6-88
(8) INTERMEDIARY PLUNGER KIT
Η
Undo the intermediary plunger guide (23).
Θ
Remove and replace the intermediary plunger kit assembly (22).

(9) GUIDE / PLUNGER AND REGULATION UNIT

ö
Beware of the plungers that might jump out due to the spring return.
Η
Remove : - Guide/plunger assembly (30).
- Regulation unit (32/33).
- Return spring (40).
- Pre-feeling point kit (42).
Θ
The remote control valve is now totally disassembled.
Assemble in reverse order following the torque specification.

6-89
 SECTION 7 ELECTRICAL SYSTEM

Group 1 Component Location ----------------------------------------------------------------------------------------- 7-1

Group 2 Electrical Circuit -------------------------------------------------------------------------------------------------- 7-3
Group 3 Monitoring System --------------------------------------------------------------------------------------------- 7-21
Group 4 Electrical Component Specification ------------------------------------------------------------------ 7-51
Group 5 Connectors --------------------------------------------------------------------------------------------------------- 7-58
Group 6 Troubleshooting -------------------------------------------------------------------------------------------------- 7-78
 SECTION 7 ELECTRICAL SYSTEM
GROUP 1 COMPONENT LOCATION

1. LOCATION 1

19 20
Cab LH side

34
A

21
12
M

32 M

9
8
67
5

18
30 31
10 11 12 13 14 15 16 17 22 23 24 25 26 27 28 29

M
A
FF
O

78097EL02

1 Beacon switch (opt) 11 Work lamp switch 22 Work load button

2 Rear wiper / washer switch 12 Kick down switch 23 Detent enable switch
3 Heated seat switch 13 Hazard switch 24 Starting switch
4 Mirror defrost switch 14 T/M shift mode switch 25 Engine mode switch
5 Emergency test switch (opt) 15 Clutch cut off mode switch 26 Pilot cut off switch
6 Attachment unlock switch (opt) 16 Multi function switch 27 Parking brake switch
7 Attachment lock switch (opt) 17 Horn switch 28 Ride control switch (opt)
8 Fan control switch 18 Monitor 29 Differential lock switch
9 Boom kickout & bucket leveler 19 Radio & USB/MP3 player 30 Machine control unit (MCU)
set switch 20 Aircon & heater switch 31 T/M control unit (TCU)
10 Main light switch 21 Engine control unit (ECU) 32 USB socket
7-1
2. LOCATION 2

1 2 3 4

OFF
11 12

13

6 7 8 9 10

77097EL02-1

1 Head lamp 6 Start relay 11 Camera (opt)

2 Horn 7 Fuel sender 12 Work lamp
3 Angle sensor 8 Battery relay 13 Number plate lamp
4 Work lamp 9 Battery
5 Master switch 10 Rear combi lamp

7-2
 ·ELECTRICAL

--------------- HARENSS CABIN-ROOF -------------------

PTC
AC HARNESS

SEAT
SEAT

REAR
1
2
3

WITH PTC

WIPER

RELAY
STEER
SWITCH
HEATER
HEATER

CN-244A
WITHOUT

HI
AC
HEAT

LOW
LAMP
TIMER

LAMP
REAR
WORK
WITH SWITCH

HORN
WORK
UNIT

FRONT

RELAY

EMERGENCY

RELAY
WIPER
RELAY
WIPER
RELAY
MIRROR
M
AC SYSTEM GND

BLOWER RELAY

A
B
C

FLASHER
SW2

2
2
2
2
2
2

1
1
1
1
1
1
GND 1

86

85
AC 24V
ILLUMINATION

Pf
B
E
AC CONTROLLER B+

NC
EMERGENCY TEST SW
WORK LAMP FRONT
NC
NC
AC OPERATE SIGNAL

BEACON LAMP
NC
MIRROR HEAT
MIRROR HEAT SWITCH
WIPER SWITCH
WORK LAMP REAR
WORK LAMP REAR

3
3
3
3
3
3
SEAT HEAT SWITCH
SEAT HEAT SWITCH
WIPER SWITCH
WIPER SWITCH

5
5
5
5
5
5
WIPER SWITCH
WORK LAMP FRONT
SWITCH ATT. LOCK
SWITCH ATT. UNLOCK
SWITCH ATT. COM
BOOM POSITION SELECT
BUCKET POSITION SLCT
NC
CASSETTE/ROOM LAMP
CASSETTE_ILLUMINATION

NC
PTC POWER

REVERCE SW_AUTO
REVERCE SW_ON
CASSETTE_IG

REVERCE SW_RETURN

30
AC COMP

REVERSE FAN SIGNAL

G
IG
A

Hi 4
2
3

Lo 5

4
4
4
4
4
4
4
3

OUT

87 87a
1

3
2

4
4
4

2
2
2
2
2
2
6

1
1
1
1
1
1

3
3
3
3
3
3
5

14
7
13
5

10
10
1

87a
4
3
2
1

5
5
5
5
5
5
15
13
14
15
2

4
4
4
4
4
4
9
5
3
6
8
3

12
11
12
11

B 85

86
8
1
6
9
7
1

85

30
A
A

L 87
B
B

87
E 86
2
2
A
1

B
7
4
6

C
2
5
8
3

CN-9
CN-7
CN-156

CR-7
CN-245

CR-26
CR-55

CR-2
CN-102
CN-170

CR-4
CR-37
CR-3
CN-244

CR-11
CN-11

CR-56
L
L

L
L
L
L
Y
V
B
B
B

B
Y
Y
Y
B
B
V
Y
B
Y
B
B
V
B
V
B
R

R
R
R
R
G

G
G

W
W
W
W
W
W
W

Br

Br
Br
Br
Gr

Gr
Gr
Gr
Gr
Or

5L
5B

LW
WITHOUT PTC

YW
BW
VW
BW

RW
RW
RW
LOr

GW
YOr

BOr
BOr

ROr
ROr
BrW

OrW
WOr

300
314
315
310
307
306
311
214
211
462
467
460
230
245
242
140
144
141
130
134
131
GW 500
RW 501
251
250
254
460
WOr 120
254
251
293
333
332
335
405
404
773
772
GOr 771
RW 770
520
LW 590
YOr 160
RW 332
333
790
791
233
234
235
160
237
293
ROr 290

G02

G02
G01
G01
G08
G09
G12
G13

310B
310A
210A
230A
290A
300A
390A
300B
114A

440D
WOr 690C

G01F

G01E

G01C
G01D
G01G
CN-4

240 2.0
11 NC

G11 2.0

131 1.25
141 1.25
131 1.25
230 0.85

2.0
2.0

2.0

2.0

2.0
36 NC

0.85
52 NC
53 NC
54 NC
55 NC
GROUP 2 ELECTRICAL CIRCUIT

56 NC

314
315
307
310
311
211
462
245
242
144
134
W 307

440A
1 WIPER MOTOR-LOW
R 315
2 WIPER MOTOR-HI
G 311
43 WIPER RY_LOW
Y 310
4 WIPER SW_LOW

520
590
160
Br 314

390A
42 WIPER SW_HI
Y 629
9 RS232 RX 2-MONITOR
L 623
10 RS232 TX 2-MONITOR
GBr 624
37 PROGRAM DUMP-MONITOR
Y 625
CR-79 38 RS232 RX-CLUSTER
L 626
2 3 4 39 RS232 TX-CLUSTER
Y 435 RY 627
1 50 PROGRAM DUMP-CLUSTER

DIFF.
LOCK
R 436
5 51 NC

RELAY
W 426A
2 05 NC
1 5 4 WOr 420A L 251A
3 13 MIRROR HEATED
----- HARNESS DASH BOARD -----

Gr 650
14 CLUSTER_BATT. 24V
Or 570C
CR-60 18 SHIFT LEVER_IG
V 580
2 3 4 27 CLUSTER_ IG
L 425 RW 935
1 6 LAMP-JOYSTICK STR
ELECTRICAL CIRCUIT (1/2) : Machine serial No.-#0031

RIDE-
Br 422 GOr 930
5 15 TCU_ED6-NEU.

SPEED
W 426 LW 920
2 16 TCU_ED5-REV.
1 5 4

CONTROL
LOr 421 BrW 910
3 17 TCU_ED4-FWD.
435 WOr 451A
21 SHIFT LEVER_KD
425 ROr 915
CR-58 22 TCU_ED1
426 GrW 925
2 3 4 23 TCU_ED2
G 193 193 VOr 905
1 24 TCU_ED3
BrW 191 540 B G14
5 25 GROUND

RELAY
Or 190 B G15
2 26 GROUND

BACK-UP
1 5 4 190A OrW 150 1.25
3
Or MAIN SWITCH_ILL
33
G 180 1.25
34 MAIN SWITCH_HEAD
LOr 154
CR-63 35 MAIN SWITCH_ILL
191 YW 214
2 3 4 19 HORN RY
B G01B 436 YOr 184 1.25
1 31 MULTI_HEAD LAMP_LOW
LOr 200 200 R 187 1.25

RELAY
5 32 MULTI_HEAD LAMP_HI
GW 202 202
2 20 NC
1 5 4 Or 190B
3 44 NC

STOP LAMP
48 NC
CR-25 49 NC
RW 501
86 30 87a 30 FLASHER_L
B G01A B 795
85 12 GROUND_SHIELD
Y 620 L 790
87 7 CAN2 LOW

RELAY
RW 531 Y 791
86 8 CAN2 HI
85 87 87a R 530B LOr 303
30 40 MCU_INT
Gr 305 305

ECM POWER
41 MCU & WASHER
Gr 305A
CR-35 3 NC
Br 300C
86 30 87a 45 FUSE BOX
B G01 Y 134
85 46 WORK LAMP SWITCH
Gr 550 2.0 VW 144
87 47 WORK LAMP SWITCH

RELAY
RW 531 531 Or 505

POWER
86 28 RH TURN
85 87 87a R 530 2.0 530A GOr 506
30 29 LH TURN
534 BrW 740
57 5V_POWER
WOr 690
CR-38 58 GND_SENSOR
LOr 754
2 3 4 59 TM MODE
R 540 BW 755
CAN2 BUS

1 60 CLUTCH_MODE

335
305
LW 538A

G02A
G02B
5
Or 570 G16

RELAY
2 1
1 5 4 Or 570 RY 627

1
1
4

2
2

NEUTRAL
3

CN-22
L 626

PUMP
3

CN-103
538
CN-127C

Y 625

WASHER

M
M
CR-5 2
86 30 87a
VW 539 539 G16
85 1
G 535 GBr 624
87 4

RELAY
LW 538 L

SAFETY
86
623 3
85 87 87a GOr 534 Y
CN-127B

30
629
2 CN-126
G16
D BATTERY(-)
BW 560
CR-46 J BATTERY(+)
G 993E
86 30 87a E CAN_Hi
L 380 V 994E
85 F CAN_Lo

FUEL
2LW 381 Y 791
87 G CAN2_Hi

RELAY
Y 370A L 790
86 H CAN2_Lo

WARMER
85 87 87a
SERVICE TOLL

2Y 370 G16
30 1
R 781 786
2 B MCU_RS232_RX
Br 782 787
CR-36 3 C MCU_RS232_TX
W 780 785
2 3 4 4 A MCU_RS232 P_DUMP
CAN BUS

GOr 371 371

1
CONNECTOR_MCU & CAN

Y 370B

RELAY
5
RW 372 372
2
CN-127

1 5 4

PRE-HEAT
Y
CN-127A

373 373
3

CN-58A
G16B
A13 GND(MAIN)
CN-36 G16A
A14 GND(MAIN)
10A BEACON WOr 120 Or 660
1 B38 ELEC. STEER MAIN PUMP PS
20A WORK LAMP_FRONT GW 130 2.0 V 661
2 B27 ELEC. STEER PUMP PS
20A WORK LAMP_REAR Y 140 2.0
3 A33 SPARE_D_IN_HIGH
20A ILL.LAMP OrW 150 150 W 306
----- MCU -----

4 B02 WIPER RY
20A HEAD LAMP G 180 2.0 180
5 B01 BUZZER
10A BACK.STOP LAMP Or 190 154 GW 671
6 B07 SPEED PULSE_TCU
20A HORN/CONVERTER ROr 210 LW 538
7 A34 NEUTRAL SIG
30A AIR-CON/HEATER 1 L 230 2.0 VW 539
8 B03 ANTI-RESTART RELAY
20A MIRROR, FUEL WARMER Gr 250 1.25 V 467
9 B12 ELEC. STEERING PUMP RELAY
30A CIGARLIGHTER G 260 260 Y 423
10 A32 RIDE CONT. ON
5Y 112 210 BrW 424
A22 RIDE CONT. AUTO
280 G 993
A07 CAN(1)-H
20A SERVICE SOCKET 1 R 270 270 V 994
11 A17 CAN(1)-L
20A SEAT HEAT/AIR-RIDE ROr 290 B 995
12 A04 CAN_SHIELD(GROUND)
20A SERVICE SOCKET 2 RW 280 R 672
13 B26 BRAKE OIL LOW PS
20A WIPER Br 300 VW 675
14 B37 PARKING OIL LOW PS
20A PARK, PILOT CUT ROr 340
15 B16 SPARE_D_OUT_HIGH
10A JOYSTICK-DETENT V 360 360 BW 735
16 B39 BOOM DOWN PR SNENSOR
20A PRE-HEAT, FUEL WARMER Y 370 440 BOr 736
17 B29 BOOM UP PR SNENSOR
20A FAN REVERSE, ATT. LW 390 R 394
18 B04 REVERSE FAN CONTROL
10A RIDE CONTROL WOr 420 RW 358
19 B21 DIFFERTIAL LOCK PR SIGNAL
10A JOYSTIC_SWITCH Gr 440 Br 680
20 A03 +24V PRESSURE SNESOR
5W 113 112 LW 705
B25 FUEL SENDOR
113 W 710
B35 HYD TEMP SENDER
103 ROr 715
B36 ALT LEVEL
CN-37 G 720
B10 COOLING FAN EPPR-
20A TURN LAMP GW 500 V 721
1 B20 COOLING FAN EPPR+
5A CASSETTE/ROOM LAMP Gr 520 B 730
2
30A START KEY SWITCH R 530 2.0 570 YW 725
3 A36 AIR FILTER
10A TCU 24V BATTERY ROr 600 600 WOr 690A 690
4 B11 GROUND_SENSOR
10A ECM 24V BATTERY W 610 2.0 B 655
5 B17 TACHO SENSOR(+)_REMOTE FAN
10A MCU 24V BATTERY GW 630 230 W 656
6 B18 TACHO SENSOR(-)_REMOTE FAN
20A AIR-CON/HEATER 2 BrW 240 2.0 240 B 730
7 B24 SPARE_ENGINE COOLANT TEMP
10A CLUSTER 24V BATTERY Gr 650 520 G16
8 B13 SPARE_PREHEATER RELAY
10A NC_SPARE 10A 390A
9 A05 SPARE_DIGITAL INPUT_LOW
15A NC_SPARE 15A 160 L 790
10 A18 CAN2 LOW
3R 103 590 Y 791
A08 CAN2 HI
LOr 303

7-3
A23 WIPER INT SIG
11 20A NC_SPARE 20A 610 Gr 305
A31 WASH SIG
621
A38 SPARE_DIGITAL INPUT_LOW
30A NC_SPARE 30A L 380
12 B14 FUEL WARMER
Y 620 Gr 235
A35 AC CONDENSOR FAN SIGNAL
13 10A ECM_IG Br 621 W 234
B15 AC COMP. OFF SIG_REVERSE FAN
Gr 550D 630 Or 233
A16 BLOWER RUN SIGNAL_DINP
10A MCU BW 560 560
14 A24 SPARE_HIGH SOURCE
Br 550C
A26 SPARE_LOW_ENGINE OIL LOW
10A TCU Or 570 570B LW 743
15 B40 BOOM POSITION SENSOR
Br 550B 570C OrW 746
B30 BUCKET POSITION SENSOR
10A CLUSTER V 580 580 BrW 740
16 A01 REF. POWER +5V
Br 550A 650
A37 MECHANICAL ENGINE SELECT
10A CASSETTE LW 590 BW 560
17 A11 POWER IG(+24V)
Br 550 2.0
A12 BATTERY POWER(+24V)
10A JOYSTICK STEER YOr 470 GW 630
18 A02 BATTERY POWER(+24V)
LOr 154 GrW 365
B09 DETENT CONTROL_BUCKET
5A ILLUMINATION 1 YOr 160 160A VOr 366
19 B08 DETENT CONTROL_BOOM UP
LOr 154A 390 YOr 364
B19 DETENT CONTROL_BOOM DOWN
5A ILLUMINATION 2 Or 170 170 L 750
20 A30 COUNT_WEIGHT_SET SWITCH
A39 SPARE_ENGINE SPEED SENSOR
BrW 740
A29 SPARE-DIGITAL INPUT-LOW
WOr 690B
A40 SPARE_SPEED PULSE
LOr 754
CS-55 B31 TM MODE SELECT SIG
B G21 BW 755
12 B28 CLUTCH CUT OFF_SLT SIG
2 1 BW 261
2 B32 ENGINE POWER MODE SELEET
Y 423 BrW 740
10 B22 SPARE_PR SIGNAL
4 Br 422 WOr 690
8 9 B05 SPARE_HOUR METER
10 8 B06 SPARE_D_OUT_HIGH
3 WOr 690C
7 A28 SPARE-DIGITAL INPUT-LOW
7 6 WOr 420
6 B33 SPARE-DIGITAL INPUT-LOW
9 423 RW 770
B23 REVERSE FAN MODE-ON
BrW 424 424 GOr 771
4 B34 REVERSE FAN MODE-AUTO

RIDE CONTROL
LOr 421 BOr 772
3 A15 BOOM POSITION SELECT SIGNAL
Or 170F LOr 773
1 A25 BUCKET POSITION SELECT SIGNAL
12 11 W 780
11 A27 PROGRAM DUMP
R 781
A19 RS-232(1) RX
Br 782
CS-17 A09 RS-232(1) TX
B G21B WOr 757
12 A21 RS-232 GND

12
Or 170B Br 758
11 A10 RS-232(2) TX
R 759
10 A20 RS-232(2) RX

10
8
9 CN-134 A06 SPARE-DIGITAL INPUT-HIGH

4
ROr 340C Or 570A
8 1

9
ROr 340B Or 800

7
7 2 CN-58B

3
W 801
4

PARKING
3
DIAGNOSTIC

LW 350 CN-157
4
Y 352 B G17
3 1 VM1-GND
G17A
1 2 VM2-GND 14
11

12 Or 800
15 SDDK-DIAGNOSTIC 16
W 801
18 EUPR-DIAGNOSTIC 33
Or 570A
6 NC 34
----- TCU -----

CS-79
12
B G21A 352 Y 352
21 ED10-PARKING BRAKE SW(+) 35
1

12

Or 170C 353 Y 353

1 66 ED9 DIFF. LOCK SWITCH 40
YW 354 354 YW 354
9 29 ED11 47
G 993
2 0 1

10 25 CANF_H 48
0,2

Or 570D V 994
5 26 CANF_L 50
4

B 995 995
6 28 VGS-CAN SHIELD 53
6

GW 671
7 36 SD4-SPEED METER CLUSTER 54
600A
10 3

8 23 VPE1-CONTINUANCE 24V 58
DIFF. LOCK
5

Y 353 ROr 600 600

3 68 VPE2-CONTINUANCE 24V 60
9

Or 570 570
4 45 VPI-POWER IG 61
Or 170 B 810 810
11 3 VMG1-SPEED PICK-UP COM 27
11

12

W 820
19 EF1-SPEED PICK-UP ENG
B 810A
27 CANF_T
RW 825
CS-4 41 EF2-SPEED PICK-UP TURBIN
B G21 B 810B 850A
12 12 VPS1-GEAR BOX VPS1(+)
1

12

Or 170 WOr 830

11 42 EF3-SPEED PICK-UP GEAR
G 840
10 4 VMG2-SPEED SENSOR OUTPUT
10

V 845
8

9 62 EF4-SPEED SENSOR(SIG)
4

ROr 340 VW 850 850

8 13 VPS1-GEAR BOX VPS1(+)
9

V 360 ROr 855

7

7 17 ER3-SW FILTER RESTRICTION

3

GOr 860
49 ER2-SENSOR TEMP CONVERTER
OrW 865
32 AIP3-GEAR BOX Y3
GrW 341 YOr 870
4 39 ER1-GEAR BOX TEMP
PILOT-CUT-OFF

V 367 WOr 875

3 46 VMGA2-GEAR BOX TEMP(COM)
BrW 880
1 51 AIP6-GEAR BOX Y6
11

12

Gr 885
55 AIP4-GEAR BOX Y4
YW 890
56 AIP1-GEAR BOX Y1
LOr 895
9 AIP5-GEAR BOX Y5
VOr 900
10 AIP2-GEAR BOX Y2
VOr 905
CN-125 20 ED3-SHIFT LEVER-X1A-B3
GW 630 BrW 910
BATTERY(+) 1 43 ED4-SHIFT LEVER X2B-FWD
BW 560 ROr 915
KEY IG(24V) 2 63 ED1-SHIFT LEVER X1C-B1
LW 920
NC 3 64 ED5-SHIFT LEVER X2C-REV
UNIT

R 759 GrW 925

SERIAL "1"_L(RX) 4 65 ED2-SHIFT LEVER X1B-B2
Br 758 GOr 930
SERIAL "1"_H(TX) 9 67 ED6-SHIFT LEVER X2D-NEU
REMOTE

WOr 757 WOr 451A 451

GROUND 5 22 ED7-SHIFT LEVER-X1D-KD
RW 935
NC 7 ADM2-JOYSTICK SELECT LAMP(-)
B G21 WOr 449
MANAGEMENT
CAN BUS

GROUND 12 31 ED13-REV-JOYSTICK
LOr 447
30 ED12-NEU-JOYSTICK
GrW 448
CN-160 44 ED8-FWD-JOYSTICK
VOr 450
NC 14 59 ED15-JOYSTICK SELLECTER(+)
WOr 451
NC 15
V 367 360 W 426
24V(DETEND) 1 8 VPS2-RIDE CONT. RY(+)
Gr 440 440 R 540
24V(HANDLE) 9 52 ADM1-START INTERLOCK RY(-)
WOr 449 449 G 193
REV 2 5 ADM4-REVERSE DRIVE RY(-)
GrW 448 448 700 L 425
FWD 3 57 ADM5-RY RIDE CONT.(-)
LOr 447 447 945 Y 435
NEUTRAL 4 11 ADM6-RY DIFF LOCK(-)
VOr 450 450 940 L 940
JOYSTICK SELECT 10 24 VMGA1-GROUND_BRAKE PEDAL
WOr 451 451 G 945
KICK DOWN 8 37 AU1-+5V SUPPLY_BRAKE PEDAL
YOr 364 364 Y 700
BOOM DOWN(-) 7 38 EU1-SIGNAL SENSOR_BRAKE PEDAL
GrW 365 365
BUCKET(-) 6
VOr 366 366
JOYSTICK LEVER

BOOM UP(-) 5 CN-167

L 750 750 B G18 1
COUNT_WEIGHT SW16 Power(-)
YW 214B YOr 470 2
HORN SWITCH 11 Power(+)
Or 170D G 993A
ILLUMINATION 12 3 CAN_H
B G19 V 994A 4
FNR SWITCH 13 CAN_L
B 995A 5 CAN_Shield
L 488 6 Input_3
OrW 487
7 Signal_Out
ROr 492 8 Valve_Power
R 216
5L

5Y

10 SENSOR(-)
5W

280
270
210
260
JOYSTIC STTERING

B G21 Br 217 9 CONTROLLER_INTPUT1

L
L
B

Y
Y
Y
B
B
B
V
V
V
B
V
Y
B
V

R
R
R
R
R
R
R
R

G
G
G
G
G

W
W
W
W
W
W

Br
Br
Br
Br

Gr
3L
3L
Or
Or
Gr
Or
Or
Gr

LW
LW
LW
LW

RW

YW
VW
VW
YW
BW

RW
RW
LOr
RW
RW
RW
LOr
RW

BOr

GW

VOr
YOr
BOr
YOr
YOr

ROr
ROr
ROr

GOr
GOr
GOr

BrW
BrW
BrW

OrW
WOr
GrW
OrW
WOr
OrW
WOr
WOr

B G19
GOr 534
531
530
531
531
2LW 381
350
341
113
113
112
112
103
202
216
217
492
487
488
945
940
211
462
405
404
394
735
141
506
505
170
390
184
187
610
621
191
200
535
422
237
245
242
373
371
372

890
900
865
885
895
880
850
870
860
855
875
114
114
675
672
700
830
825
820
810
845
840
746
743
740
660
661
715
705
725
710
721
720
730
680
436

358
736
656
655

570B
440A
160A

810B
810A
690A
995C
994C
993C

B G22
B
B
B
B
B
B

R
R
R
2.0

G
Or
3.0
3.0
3.0
3.0
3.0
3.0
3.0

RW

EARTH

B G20
3
3

9
8
7
6
9
8
7
6

4
1
4
1

5
5

2
2

280
270
220
ROr 210
260
220
WOr 690
BW 261
BrW 740

G20
G20
G22
CN-6

CN-5

48
47
46
45
44
43
36
41
40
39
38
37
32
35
34
33
42
31
30
29
28
27
26
25
24
23
22
21
20
14
13
15
17
16
19
18
12
11
10
13
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
43
42
41
36
29
37
22
21
23
24
33
35
34
32
31
30
44
28
27
26
25
38
40
39
20
19
18
17
16
15
14
12
11
10

170E
WOr 405A

G22B
G22A
G22C
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

1
HORN

2 2
2

2
2

1 1
1
5
4
2

6
1
3

A
B
C
SHIELD

CL-2
CS-2
PARKING

CN-26
CS-80
AC R/DRY
AC R/DRY
AC COMP.

CN-139

CN-172

CN-171

B
CN-138
ECM-J1939-

STOP LAMP

REAR LAMP
ECM-J1939+

1
SENSOR_24V

0, I
12V
24V
START RELAY

TUN LAMP_LH

2.5
FUEL SENDER
BACK BUZZER

TUN LAMP_RH

GND
MAIN PUMP PS
ALTERNATOR I
GROUND_MCU
HEAD LIGHT HI

GEAR BOX - Y1
GEAR BOX - Y2
GEAR BOX - Y3
GEAR BOX - Y4
GEAR BOX - Y5
GEAR BOX - Y6

SERVICE SERVICE
FUEL WARMER
ATT. LOCK SOL

FUSIBLE LINK 2
FUSIBLE LINK 2
FUSIBLE LINK 2
FUSIBLE LINK 2
FUSIBLE LINK 1

PILOT CUT-OFF
ECM POWER IG
DIFF. LOCK SOL

REF. POWER 5V

GEAR BOX TEMP

HEAD LIGHT LOW
PRE-HEAT RELAY

ATT. UNLOCK SOL

SOCKET SOCKET
ECM BATTERY 24V
ECM-J1939 SHIELD

GEAR BOX VPS1(+)

TEMP CONVERTER
HYD TEMP SENSER

12V
STEERING PUMP PS

4
RIDE CONTORL SOL.

FAN SPEED SENSOR

FAN SPEED SENSOR

SPEED SENSOR_24V

FILTER RESTRICTION
SENSOR_STOP LAMP
JUMP WIRE-JOYSTICK
AIR CLEANER SWITCH
BOOM UP PR SENSOR
ECM-AIR HEATER OUT

H0 I
BATTERY RELAY(DO-1)
SEERING PUMP RELAY
SEERING PUMP RELAY

GEAR BOX TEMP(COM)

SPEED SENSOR_VMG2

3
2

6
5

V
SPEED SENSOR_EF4(2)

24V
PRO-PORTIONAL VALVE
PRO-PORTIONAL VALVE
PRO-PORTIONAL VALVE

C BR ACC H
TURBIN PICK-UP SENSER
TURBIN PICK-UP SENSER
FAN REVERSAL SOL _24V

BOOM POSITION SENSOR

BOOM DOWN PR SENSOR

ENGINE PICK-UP SENSOR

ENGINE PICK-UP SENSOR
ECM-AIR HEATER RETURN

BUCKET POSITION SENSOR

FAN PROPORTIONAL VALVE
FAN PROPORTIONAL VALVE
REAR COMBI_ILLUMINATION
REAR COMBI_ILLUMINATION

PTC POWER_BATTERY RELAY

PTC POWER_BATTERY RELAY
INTER GEAR PICK-UP SENSOR
INTER GEAR PICK-UP SENSOR
FAN REVERSAL SOL CONTORL

BUZZER
PRESSURE SENSOR_JOYSTICK

CLUTCHBRAKE PEDALSENSING
BRAKE OIL PRESSURE SENSING
DIFFERENTIAL SHIFT PR SENSOR

CIGAR
PARK BRAKE PRESSURE SENSING
BRAKE PEDAL_CLUCH CUTOFF_5V+
BRAKE PEDAL_CLUCH CUTOFF_GND

SWITCH

12V SOCKET
SWITCH
START KEY

----- HARNESS FRAME -----

ECONO MODE

DC/DC CONVERTER

77097EL01
 CAB-ROOF HARNESS
·ELECTRICAL

PTC
AC HARNESS

SEAT

REAR
1
2
3

HI
WITH PTC

WIPER
OPTION

RELAY
CN-244A

STEER
HEATER

LOW
AC

HORN
HEAT

RELAY
WIPER
RELAY
WIPER
RELAY
TIMER

LAMP

LAMP
REAR
WORK
MIRROR
WITH SWITCH

UNIT

WORK
FRONT

RELAY

EMERGENCY
A
B
C

M
AC SYSTEM GND

FLASHER
BLOWER RELAY

SW2

2
2
2
2
2
2

1
1
1
1
1
1
GND 1

86

85
AC 24V

SWITCH ATT. COM

ILLUMINATION

WIPER SWITCH
WIPER SWITCH
WIPER SWITCH
SWITCH ATT. UNLOCK
Pf

NC
NC
B
E

SWITCH ATT. LOCK

NC

BUCKET POSITION SLCT

MIRROR HEAT
MIRROR HEAT SWITCH
AC CONTROLLER B+

REVERCE SW_ON

BEACON LAMP

NC
NC
NC
NC
BOOM POSITION SELECT
NC

WORK LAMP FRONT

WORK LAMP FRONT
AC OPERATE SIGNAL

WORK LAMP REAR

WORK LAMP REAR
CASSETTE/ROOM LAMP

3
3
3
3
3
3

5
5
5
5
5
5
WIPER SWITCH
REVERCE SW_AUTO
CASSETTE_ILLUMINATION
PTC POWER

EMERGENCY TEST SW

30
AC COMP

REVERSE FAN SIGNAL

G
REVERCE SW_RETURN

IG
A

CASSETTE_IG
Hi 4
2
3

Lo 5

4
4
4
4
4
4
4
3

OUT

87 87a

CR-4
CR-7
1

3
2

4
4
4

2
2
2
2
2
2
6

1
1
1
1
1
1
5

3
3
3
3
3
3
14
7
13
5

10
10
1

87a
4
3
2
1

5
5
5
5
5
5
15
13
14
15
2

4
4
4
4
4
4
CR-3
9
5
3
6
8
3

12
11
12
11

B 85

86
8
1
6
9
7
1

85

30
A

L 87
B

E 86

87

CR-2
2
2
A
1

B
7
4
6

C
2
5
8
3

CN-244

CR-26
CR-55
CN-102
CN-245

CN-9
CN-7

CR-37
CR-11
CN-11
CN-156

CR-56

L
L
L
L
L
L

B
Y
Y
Y
B
B
V
Y
B
Y
B
B
V
B
V
B
Y
V
B
B

R
R
R

G
G
G

W
W
W
W
W
W
W

Br
Br
Br
Br

Gr
Gr
Gr
Gr
Or
Gr

5L
5B

LW
WITHOUT PTC

YW
BW
VW
BW

RW
RW
LOr
RW

GW
BOr
BOr
YOr

ROr
BrW

WOr

300
314
315
310
307
306
311
214
211
462
467
460
230
245
242
140
144
141
130
134
131
GW 500
RW 501
251
250
254
460
WOr 120
254
251
333
RW 332
OrW 335
405
404
773
772
GOr 771
RW 770
520
LW 590
YOr 160
332
333
790
791
114
233
234
235
160
237
ROr 290

G02

G02
G01
G01
G08
G09
G13

310B
310A
210A
230A
300A
390A
300B

440D
WOr 690C

G01F

G01E

G01C
G01D
G01G
240 2.0
G11 2.0

131 1.25
141 1.25
131 1.25
230 0.85

2.0
2.0

2.0

2.0

2.0
0.85

314
315
307
310
311
211
462
245
242
144
134
W 307

440A
1 WIPER MOTOR-LOW
R 315
2 WIPER MOTOR-HI
G 311
43 WIPER RY_LOW
Y 310
4 WIPER SW_LOW

520
590
160
Br 314

390A
42 WIPER SW_HI
Y 629
9 RS232 RX 2-MONITOR
L 623
10 RS232 TX 2-MONITOR
GBr 624
37 PROGRAM DUMP-MONITOR
Y 625
CR-79 38 RS232 RX-CLUSTER
L 626
86 30 87a 39 RS232 TX-CLUSTER
Y 435 RY 627
85 50 PROGRAM DUMP-CLUSTER

DIFF.
LOCK
R 436
TO SHEET 2 OF 2

87

RELAY
W 426A
86
85 87 87a WOr 420A L 251A
30 13 MIRROR HEATED
Gr 650
14 CLUSTER_BATT. 24V
Or 570C
CR-60 18 SHIFT LEVER_IG
V 580
86 30 87a 27 CLUSTER_ IG
L 425 RW 935
85 6 LAMP-JOYSTICK STR

RIDE-
Br 422 GOr 930
ELECTRICAL CIRCUIT (1/2) : Machine serial No.#0032-

87 15 TCU_ED6-NEU.

SPEED
W 426 LW 920
86 16 TCU_ED5-REV.
85 87 87a

CONTROL
LOr 421 BrW 910
30 17 TCU_ED4-FWD.
435 WOr 451A
21 SHIFT LEVER_KD
425 ROr 915
CR-58 22 TCU_ED1
426 GrW 925
2 3 4 23 TCU_ED2
G 193 193 VOr 905
1 24 TCU_ED3
BrW 191 540
5

RELAY
Or 190
2

BACK-UP
1 5 4 190A OrW 150 1.25
3
Or
33 MAIN SWITCH_ILL
G 180 2.0
34 MAIN SWITCH_HEAD
CR-63 LOr 154
35 MAIN SWITCH_ILL
191 YW 214
2 3 4 19 HORN RY
B G01B 436 YOr 184 1.25
1 31 MULTI_HEAD LAMP_LOW
LOr 200 200 R 187 1.25

RELAY
5 32 MULTI_HEAD LAMP_HI
GW 202 202
2
1 5 4 Or 190B
3

STOP LAMP
CR-25
RW 501
86 30 87a 30 FLASHER_L
B G01A B 795
85 12 GROUND_SHIELD
Y 620 L 790
87 7 CAN2 LOW

RELAY
RW 531 Y 791
86 8 CAN2 HI
85 87 87a R 530B LOr 303
30 40 MCU_INT
Gr 305 305

ECM POWER
41 MCU & WASHER
Gr 305A
CR-35
Br 300C
86 30 87a 45 FUSE BOX
B G01 Y 134
85 46 WORK LAMP SWITCH
Gr 550 2.0 VW 144
87 47 WORK LAMP SWITCH

RELAY
RW 531 531 Or 505

POWER
86 28 RH TURN
85 87 87a R 530 2.0 530A GOr 506
30 29 LH TURN
534 BrW 740
57 5V_POWER
WOr 690
CR-38 58 GND_SENSOR
LOr 754
2 3 4 59 TM MODE
R 540 BW 755
CAN2 BUS

1 60 CLUTCH_MODE

335
305
LW 538A

G02A
G02B
5
Or 570 G16

RELAY
2 1
1 5 4 Or 570 RY 627

1
1
4

2
2

NEUTRAL
3

CN-22
L 626

PUMP
3

CN-103
M

M
CN-127C

538 Y 625

WASHER
CR-5 2
86 30 87a
VW 539 539 G16
85 1
G 535 GBr 624
87 4

RELAY
LW 538 L

SAFETY
86
623 3
CN-127B

85 87 87a GOr 534 Y

30
629 CN-126
2
G16
D BATTERY(-)
BW 560
CR-46 J BATTERY(+)
G 993E
86 30 87a E CAN_Hi
L 380 V 994E
85 F CAN_Lo

FUEL
2LW 381 Y 791
87 G CAN2_Hi

RELAY
SERVICE TOLL

Y 370A L 790
86 H CAN2_Lo

WARMER
85 87 87a 2Y 370
30
G16 1
R 781 786
2 B MCU_RS232_RX
Br 782 787
CR-36 3 C MCU_RS232_TX
CONNECTOR_MCU & CAN

W 780 785
2 3 4 4 A MCU_RS232 P_DUMP
CAN BUS

GOr 371 371

1
Y 370B

RELAY
5
RW 372 372
2
CN-127

1 5 4

PRE-HEAT
CN-127A

Y 373 373
3

CN-58
CN-58A
G16B
A13 GND(MAIN)
CN-36 G16A
A14 GND(MAIN)
10A BEACON WOr 120 Or 660
15 B38 ELEC. STEER MAIN PUMP PS
20A WORK LAMP_FRONT GW 130 2.0 V 661
16 B27 ELEC. STEER PUMP PS
20A MIRROR,SER.SOCKET2 RW 280
17 A33 SPARE_D_IN_HIGH
20A ILL.LAMP OrW 150 150 W 306
----- MCU -----

18 B02 WIPER RY
20A HEAD LAMP G 180 2.0 180
19 B01 BUZZER
10A BACK.STOP LAMP Or 190 154 GW 671
20 B07 SPEED PULSE_TCU
20A HORN/CONVERTER ROr 210 LW 538
21 A34 NEUTRAL SIG
30A AIR-CON/HEATER 1 L 230 2.0 VW 539
22 B03 ANTI-RESTART RELAY
20A FUEL WARMER Gr 250 1.25 V 467
23 B12 ELEC. STEERING PUMP RELAY
30A CIGARLIGHTER G 260 260 Y 423
24 A32 RIDE CONT. ON
W 112 8.0 210 BrW 424
A22 RIDE CONT. AUTO
280 G 993
A07 CAN(1)-H
20A SERVICE SOCKET 1 R 270 270 V 994
25 A17 CAN(1)-L
20A SEAT HEAT/AIR-RIDE ROr 290 B 995
26 A04 CAN_SHIELD(GROUND)
20A WORK LAMP_REAR Y 140 2.0 R 672
27 B26 BRAKE OIL LOW PS
20A WIPER Br 300 VW 675
28 B37 PARKING OIL LOW PS
20A PARK, PILOT CUT ROr 340
29 B16 SPARE_D_OUT_HIGH
10A JOYSTICK-DETENT V 360 360 BW 735
30 B39 BOOM DOWN PR SNENSOR
20A PRE-HEAT, FUEL WARMER Y 370 440 BOr 736
31 B29 BOOM UP PR SNENSOR
20A FAN REVERSE, ATT. LW 390 R 394
32 B04 REVERSE FAN CONTROL
10A RIDE CONTROL WOr 420 RW 358
33 B21 DIFFERTIAL LOCK PR SIGNAL
10A JOYSTIC_SWITCH Gr 440 Br 680
34 A03 +24V PRESSURE SNESOR
112 LW 705
B25 FUEL SENDOR
Y 112A 8.0 112A W 710
B35 HYD TEMP SENDER
103 ROr 715
B36 ALT LEVEL
G 720
B10 COOLING FAN EPPR-
20A TURN LAMP GW 500 V 721
1 B20 COOLING FAN EPPR+
5A CASSETTE/ROOM LAMP Gr 520 B 730
2
30A START KEY SWITCH R 530 2.0 570 YW 725
3 A36 AIR FILTER
10A TCU 24V BATTERY ROr 600 600 WOr 690A 690
4 B11 GROUND_SENSOR
20A ECM 24V BATTERY W 610 2.0 B 655
5 B17 TACHO SENSOR(+)_REMOTE FAN
20A MCU 24V BATTERY GW 630 230 W 656
6 B18 TACHO SENSOR(-)_REMOTE FAN
20A AIR-CON/HEATER 2 BrW 240 2.0 240 B 730
7 B24 SPARE_ENGINE COOLANT TEMP
10A CLUSTER 24V BATTERY Gr 650 520 G16
8 B13 SPARE_PREHEATER RELAY
390A
A05 SPARE_DIGITAL INPUT_LOW
3R 103 160 L 790
A18 CAN2 LOW
590 Y 791
A08 CAN2 HI

7-4
LOr 303
A23 WIPER INT SIG

7-3-1
610 Gr 305
A31 WASH SIG
621
A38 SPARE_DIGITAL INPUT_LOW
L 380
B14 FUEL WARMER
Y 620 Gr 235
A35 AC CONDENSOR FAN SIGNAL
10A ECM_IG Br 621 W 234
9 B15 AC COMP. OFF SIG_REVERSE FAN
Gr 550 630 Or 233
A16 BLOWER RUN SIGNAL_DINP
10A MCU BW 560 560
10 A24 SPARE_HIGH SOURCE
A26 SPARE_LOW_ENGINE OIL LOW
10A TCU Or 570 570B LW 743
11 B40 BOOM POSITION SENSOR
570C OrW 746
B30 BUCKET POSITION SENSOR
10A CLUSTER V 580 580 BrW 740
12 A01 REF. POWER +5V
650
A37 MECHANICAL ENGINE SELECT
10A CASSETTE LW 590 BW 560
13 A11 POWER IG(+24V)
A12 BATTERY POWER(+24V)
10A JOYSTICK STEER YOr 470 GW 630
14 A02 BATTERY POWER(+24V)
LOr 154 GrW 365
B09 DETENT CONTROL_BUCKET
5A ILLUMINATION 1 YOr 160 160A VOr 366
35 B08 DETENT CONTROL_BOOM UP
390 YOr 364
B19 DETENT CONTROL_BOOM DOWN
5A ILLUMINATION 2 Or 170 170 L 750
36 A30 COUNT_WEIGHT_SET SWITCH
A39 SPARE_ENGINE SPEED SENSOR
BrW 740
A29 SPARE-DIGITAL INPUT-LOW
WOr 690B
A40 SPARE_SPEED PULSE
CS-55 LOr 754
B31 TM MODE SELECT SIG
B G21 BW 755
12 B28 CLUTCH CUT OFF_SLT SIG
2 1 BW 261
2 B32 ENGINE POWER MODE SELEET
Y 423 BrW 740
10 B22 SPARE_PR SIGNAL
4 Br 422 WOr 690
8 9 B05 SPARE_HOUR METER
10 8 B06 SPARE_D_OUT_HIGH
3 WOr 690C
7 A28 SPARE-DIGITAL INPUT-LOW
7 6 WOr 420
6 B33 SPARE-DIGITAL INPUT-LOW
9 423 RW 770
B23 REVERSE FAN MODE-ON
BrW 424 424 GOr 771
4 B34 REVERSE FAN MODE-AUTO
LOr 421 BOr 772
3 A15 BOOM POSITION SELECT SIGNAL

RIDE CONTROL SW
Or 170F LOr 773
1 A25 BUCKET POSITION SELECT SIGNAL
12 11 W 780
11 A27 PROGRAM DUMP
R 781
A19 RS-232(1) RX
CS-17 Br 782
A09 RS-232(1) TX
B G21B WOr 757
12 A21 RS-232 GND

12
Or 170B Br 758
11 A10 RS-232(2) TX
R 759
10 A20 RS-232(2) RX

10
8 SPARE-DIGITAL INPUT-HIGH
9 CN-134 A06

4
ROr 340C Or 570A
8 1

9
ROr 340B Or 800
7

7 2

3
W 801 CN-58B
4

PARKING SW
3
DIAGNOSTIC

LW 350 CN-157
4 6
Y 352 B G17
3 1 VM1-GND
G17A
1 2 VM2-GND 14
11

12

Or 800
15 SDDK-DIAGNOSTIC 16
W 801
18 EUPR-DIAGNOSTIC 33
CS-79 Or 570A
6 NC 34
----- TCU -----

12
B G21A 352 Y 352
21 ED10-PARKING BRAKE SW(+) 35
1

12

Or 170C 354 Y 353

1 66 ED9 DIFF. LOCK SWITCH 40
Y 353 353 YW 354
9 29 ED11 47
G 993
2 0 1

10 25 CANF_H 48
0,2

Or 570D V 994
5 26 CANF_L 50
4

B 995 995
6 28 VGS-CAN SHIELD 53
6

GW 671
DIFF. LOCK SW

7 36 SD4-SPEED METER CLUSTER 54

600A
10 3

8 23 VPE1-CONTINUANCE 24V 58
5

YW 354 ROr 600 600

3 68 VPE2-CONTINUANCE 24V 60
9

Or 570 570
4 45 VPI-POWER IG 61
Or 170 B 810 810
11 3 VMG1-SPEED PICK-UP COM 27
11

12

W 820
19 EF1-SPEED PICK-UP ENG
B 810A
27 CANF_T
CS-4 RW 825
41 EF2-SPEED PICK-UP TURBIN
B G21 B 810B 850A
12 12 VPS1-GEAR BOX VPS1(+)
1

12

Or 170 WOr 830

11 42 EF3-SPEED PICK-UP GEAR
G 840
10 4 VMG2-SPEED SENSOR OUTPUT
10

V 845
8

9 62 EF4-SPEED SENSOR(SIG)
4

ROr 340 VW 850 850

8 13 VPS1-GEAR BOX VPS1(+)
9

V 360 ROr 855

7

7 17 ER3-SW FILTER RESTRICTION

3

GOr 860
49 ER2-SENSOR TEMP CONVERTER
OrW 865
32 AIP3-GEAR BOX Y3
GrW 341 YOr 870
PILOT-CUT-OFF SW

4 39 ER1-GEAR BOX TEMP

V 367 WOr 875
3 46 VMGA2-GEAR BOX TEMP(COM)
BrW 880
1 51 AIP6-GEAR BOX Y6
11

12

Gr 885
55 AIP4-GEAR BOX Y4
YW 890
56 AIP1-GEAR BOX Y1
LOr 895
9 AIP5-GEAR BOX Y5
VOr 900
10 AIP2-GEAR BOX Y2
VOr 905
CN-125 20 ED3-SHIFT LEVER-X1A-B3
GW 630 BrW 910
BATTERY(+) 1 43 ED4-SHIFT LEVER X2B-FWD
BW 560 ROr 915
KEY IG(24V) 2 63 ED1-SHIFT LEVER X1C-B1
UNIT

LW 920
NC 3 64 ED5-SHIFT LEVER X2C-REV
R 759 GrW 925
SERIAL "1"_L(RX) 4 65 ED2-SHIFT LEVER X1B-B2
REMOTE

Br 758 GOr 930

SERIAL "1"_H(TX) 9 67 ED6-SHIFT LEVER X2D-NEU
WOr 757 WOr 451A 451
GROUND 5 22 ED7-SHIFT LEVER-X1D-KD
RW 935
MANAGEMENT

NC 7 ADM2-JOYSTICK SELECT LAMP(-)

B G21 WOr 449
CAN BUS

GROUND 12 31 ED13-REV-JOYSTICK
LOr 447
30 ED12-NEU-JOYSTICK
GrW 448
CN-160 44 ED8-FWD-JOYSTICK
VOr 450
NC 14 59 ED15-JOYSTICK SELLECTER(+)
WOr 451
NC 15
V 367 360 W 426
24V(DETEND) 1 8 VPS2-RIDE CONT. RY(+)
Gr 440 440 R 540
24V(HANDLE) 9 52 ADM1-START INTERLOCK RY(-)
WOr 449 449 G 193
REV 2 5 ADM4-REVERSE DRIVE RY(-)
GrW 448 448 700 L 425
FWD 3 57 ADM5-RY RIDE CONT.(-)
LOr 447 447 945 Y 435
CN-246

NEUTRAL 4 11 ADM6-RY DIFF LOCK(-)

VOr 450 450 940 L 940
JOYSTICK SELECT 10 24 VMGA1-GROUND_BRAKE PEDAL
WOr 451 451 G 945
KICK DOWN 8 37 AU1-+5V SUPPLY_BRAKE PEDAL
YOr 364 364 Y 700
JOYSTICK LEVER

BOOM DOWN(-) 7 38 EU1-SIGNAL SENSOR_BRAKE PEDAL

GrW 365 365
BUCKET(-) 6
VOr 366 366
BOOM UP(-) 5 CN-167
L 750 750 B G18 1
COUNT_WEIGHT SW 16 Power(-)
YW 214B YOr 470 2
HORN SWITCH 11 Power(+)
Or 170D G 993A
ILLUMINATION 12 3 CAN_H
B G19 V 994A 4
FNR SWITCH 13 CAN_L
B 995A 5 CAN_Shield
L 488 6 Input_3
OrW 487
7 Signal_Out
8.0
8.0
5.0

ROr 492 8 Valve_Power

L

R 216
W
JOYSTIC STTERING

10 SENSOR(-)
280
270
210
260

B G21 Br 217 9 CONTROLLER_INTPUT1

L
L
B

Y
B
B
B
V
V
V
B
V
Y
B
V

R
R
R
R
R
R
R
R

G
G
G
G
G

W
W
W
W
W
W
W
W
W
W

Br
Br
Br
Br

Gr
Or
Or
Gr
Or
Or
Gr

LW
LW
LW
LW

RW

YW
VW
VW
YW
BW

RW
RW
LOr
RW
RW
RW
LOr
RW

BOr

GW

VOr
YOr
BOr
YOr
YOr

ROr
ROr
ROr

GOr
GOr
GOr

BrW
BrW
BrW

OrW
WOr
GrW
OrW
WOr
OrW
WOr
WOr

B G19
EARTH
890
900
865
885
895
880
850
870
860
855
875
112
112
675
672
700
830
825
820
810
845
840
746
743
740
660
661
715
705
725
710
721
720
730
680
436

GOr 534
531
530
531
531
2LW 381
350
341
112
112
112
112
103
202
216
217
492
487
488
945
940
211
462
405
404
394
735
141
506
505
170
390
184
187
610
621
191
200
535
422
237
245
242
373
371
372

358
736
656
655

810B
810A
690A

570B
440A
160A
995C
994C
993C

B G22
B
B
B
B
B
B

R
R
R
2.0

G
Or
3.0
3.0
3.0
3.0
3.0
3.0
3.0

B G20
3
3

9
8
7
6
9
8
7
6

4
1
4
1

5
5

2
2

RW 280
270
WOr 690
BW 261
BrW 740

220
ROr 210
260
220

G20
G20
G22
48
47
46
45
44
43
36
41
40
39
38
37
32
35
34
33
42
31
30
29
28
27
26
25
24
23
22
21
20
14
13
15
17
16
19
18
12
11
10
13
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
43
42
41
36
29
37
22
21
23
24
33
35
34
32
31
30
44
28
27
26
25
38
40
39
20
19
18
17
16
15
14
12
11
10

CN-5
CN-6

170E
WOr 405A

G22B
G22A
G22C
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

1
HORN

2 2
2

2
2

1 1
1
5
4
2

6
1
3

A
B
C
SHIELD

CL-2
CS-2
PARKING
AC R/DRY
AC R/DRY

CN-26
AC COMP.

CN-172
1

CN-171

B
FUSE MAXI
FUSE MAXI
FUSE MAXI
FUSE MAXI
FUSE MAXI
FUSE MAXI
FUSE MAXI

CS-80

CN-139

CN-138
ECM-J1939-

STOP LAMP

REAR LAMP
ECM-J1939+

1
SENSOR_24V

0, I
12V
24V
START RELAY

TUN LAMP_LH

2.5
FUEL SENDER
BACK BUZZER

TUN LAMP_RH

GND

SERVICE
MAIN PUMP PS
ALTERNATOR I
GROUND_MCU
HEAD LIGHT HI

SERVICE
GEAR BOX - Y1
GEAR BOX - Y2
GEAR BOX - Y3
GEAR BOX - Y4
GEAR BOX - Y5
GEAR BOX - Y6
FUEL WARMER
ATT. LOCK SOL

PILOT CUT-OFF
ECM POWER IG
DIFF. LOCK SOL

REF. POWER 5V

GEAR BOX TEMP

SOCKET SOCKET
HEAD LIGHT LOW
PRE-HEAT RELAY

ATT. UNLOCK SOL

ECM BATTERY 24V
ECM-J1939 SHIELD

GEAR BOX VPS1(+)

TEMP CONVERTER
HYD TEMP SENSER

12V
STEERING PUMP PS

4
RIDE CONTORL SOL.

FAN SPEED SENSOR

FAN SPEED SENSOR

SPEED SENSOR_24V

FILTER RESTRICTION
SENSOR_STOP LAMP
JUMP WIRE-JOYSTICK
AIR CLEANER SWITCH
BOOM UP PR SENSOR
ECM-AIR HEATER OUT

H0 I
BATTERY RELAY(DO-1)
SEERING PUMP RELAY
SEERING PUMP RELAY

GEAR BOX TEMP(COM)

SPEED SENSOR_VMG2

3
2

6
5

V
SPEED SENSOR_EF4(2)

24V
PRO-PORTIONAL VALVE
PRO-PORTIONAL VALVE
PRO-PORTIONAL VALVE

C BR ACC H
TURBIN PICK-UP SENSER
TURBIN PICK-UP SENSER
FAN REVERSAL SOL _24V

BOOM POSITION SENSOR

BOOM DOWN PR SENSOR

ENGINE PICK-UP SENSOR

ENGINE PICK-UP SENSOR
ECM-AIR HEATER RETURN

BUCKET POSITION SENSOR

FAN PROPORTIONAL VALVE
FAN PROPORTIONAL VALVE
REAR COMBI_ILLUMINATION
REAR COMBI_ILLUMINATION

INTER GEAR PICK-UP SENSOR

INTER GEAR PICK-UP SENSOR
FAN REVERSAL SOL CONTORL

PRESSURE SENSOR_JOYSTICK

CLUTCHBRAKE PEDALSENSING
BRAKE OIL PRESSURE SENSING

CIGAR
BUZZER
DIFFERENTIAL SHIFT PR SENSOR

PARK BRAKE PRESSURE SENSING

BRAKE PEDAL_CLUCH CUTOFF_5V+
BRAKE PEDAL_CLUCH CUTOFF_GND

12V SOCKET
SWITCH

SWITCH
START KEY

DC/DC CONVERTER
ECONO MODE

FRAME HARNESS
77097EL101
·ELECTRICAL
ELECTRICAL CIRCUIT (2/2) : Machine serial No.-#0031
CN-94
RW 375 GRID HEATER ACTUATOR SIGNAL
OFF IDLE 10 DIFF.LOCK
5 GOr 374 BOOM BOOM
11 GRID HEATER / SWITED OUTPUT RETURN DOWN UP FEED BACK

LINEAR THROTTLE
COOLENT LEVEL RETURN MP3 PLAYER POWER CONNECT SUB CONNECTOR
3
19 PR SENSOR PR SENSOR P.SENSOR
- S+ - S+ - S+ SPARE ATT. LOCK ATT. UNLOCK KICK DOWN SET AUTO REVERSE FAN EMERGENCY TEST
7 COOLENT LEVEL SW +5 SUPPLY 12 12
CN-162 10 4 9 3

REMOCON GND
12
12 12 12

12
DIFF.LOCK 12 12 12 12

5
6 COOLENT LEVEL LOW SWITCH 10 4 9 3 0 1 10 4 9 3 0 1 3 9 4 10 4 3

SPK FRT RH+

THROTTLE 2

SPK FRT LH+

SPK FRT RH-
SPK FRT LH-
G 647

REMOCON+
6 5 COOLENT LEVEL HIGH SWITCH SOL. CN-20 0,2

BACK UP+
TEL MUTE

AUX_GND
ASSEMBLY

USB GND
YOr 646 G56

ANT 12V
A Pa

A Pa

A Pa

USB D+
1

USB 5V
5 1

USB D-

AUX_R
31P OEM

AUX_L
Or 645 213

CD-81

CD-80

CD-79
CN-93

CN-79

GND
ACC