Twin Splitter Transmission

Service Manual

T20113
Issue 01 / 2001

Eaton Twin Splitter Transmission

Truck Components Operations Europe

PO Box 11 Worsley
Manchester M28 5GJ
England

Service Manual

5/01

Section 1
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1/2
1/3
1/4
1/5
1/7
1/9
1/10

Section 2
2/1
2/2
2/3
2/4
2/5
2/6
2/7
2/8
2/9
2/10
2/11
2/12
2/14
2/16
2/17

Section 3
3/1
3/2
3/3
3/4
3/5
3/6

General
Letter and Model Designation
Technical Data
Lubrication
Recommended Lubricants
Torque Tightening Recommendations
Disassembly Precautions and Inspection of Expendable Parts
Reassembly Precautions
Special Tools

Air System
General Description - 12 Speed
Single H Pattern Gear Change
Splitter System - Signal Connections
Filter Pressure Regulator
Selector Valve Switch
Selector Valve - Removal and Refitment
Pulse Unit
Splitter Shift - Cylinder Operation
Splitter Cylinder Cover Assembly - Logic Valves
Splitter Cylinder Cover Assembly - Twin Spool Valves
Splitter Gear Air Line Connections
Splitter Air Circuit Diagrams - Logic Valves
Splitter Air Circuit Diagrams - Twin Spool Valves
Splitter Cylinder - Disassembly and Reassembly
Splitter Cylinder Cover - Trouble Shooting Hints

Shifting Controls
Remote Control - Exploded View
Disassembly of Remote Control (LRC)
Reassembly of Remote Control (LRC)
Shift Bar Housing - Exploded View
Shift Bar Housing Disassembly
Shift Bar Housing Reassembly

>>>>

5/01

Section 4
4/1
4/5
4/7
4/7
4/8
4/9
4/13
4/17
4/17
4/19
4/20
4/24
4/26
4/36
4/42

Section 5
5/1
5/2

Section 6
6/1
6/2
6/4

Section 7
7/1
7/2

Main Transmission
Auxiliary Section Removal and Disassembly
Output Shaft and Rear Sliding Gear Removal and Disassembly
Auxiliary Countershaft Bearing Renewal
Auxiliary Section Splitter Gears and Sensor Disassembly
Splitter Gears Reassembly
Output Shaft and Rear Sliding Gear Reassembly and Installation
Main Section Disassembly
Input Shaft Disassembly
Input Shaft Reassembly
Reverse Idler Gear Disassembly and Reassembly
Mainshaft Disassembly
Mainshaft End Float
Mainshaft Reassembly
Main Transmission Reassembly
Auxiliary Section Reassembly

Changing the Input Shaft

Input Shaft Disassembly
Input Shaft Reassembly

Upshift Brake
Upshift Brake - Exploded View
Upshift Brake Disassembly
Upshift Brake Reassembly

PTO Installation
Fitting Extended Countershaft
Assembly of Extended Countershaft

<<<<

5/01

Section 1

General

5/01

General
Letter and Model Designation

Example: TS 12612A
TSO 12612A
T

- Twin Countershaft

- Splitter Transmission

- Overdrive

12

- Code input torque

- Design level

12

- Number of forward speeds

- Specific ratio type

1/1

5/01

General

Technical Data

MODELS TS(O) 11612A, TS(O) 12612A, TS(O) 13612A, TS(O) 15612A

Permissible Torque
TS(O) 11612A

1560 Nm

TS(O) 12612A

1730 Nm

TS(O) 13612A

1815 Nm

TS(O) 15612A

2080 Nm

Weight1)

325 kg

Length2)

745 mm

Oil capacity approx.

12,5 lit

Aux. Drive possibilities

1 x Rear of transmission, lower left
Right side SAE - standard 6 bolt
Bottom SAE - standard 8 bolt
Output speed X Engine
for rear PTO and drive
SAE 6 and 8 bolt

0,51

Clutch Housing

SAE 1 or 2 for Pull and Push Clutch

Grey Iron
or
Aluminium

1) excluding oil, clutch housing and controls

2) from front of main case to the mounting face of the output flange (depending on flange fitted)

1/2

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General

Lubrication
Proper Oil Level

2. High engine RPM

Before checking the oil level or refilling, vehicle

should be on level ground. Make sure that the oil is
level with the filler opening. Because you can reach
the oil with your finger does not mean oil is at the
proper level.

3. High ambient temperature

4. Restricted air flow around transmission
5. Exhaust system too close to transmission
6. High housepower, over;drive operation
High operating temperatures may require more
frequent oil changes.
External cooler kits are available to keep the
transmission operating temperature under 120C
when the conditions described above are
encountered.

1. Oil Level

2. Yes

If the tranmission operating angle is more than 12,

improper lubrication can occur. The operating angle
is the transmission mounting angle in the chassis
plus the percent or upgrade (expressed in
degrees).

3. No

Draining Oil
Drain transmission while oil is warm. To drain oil
remove the drain plug at the bottom of case.

Refilling
Clean the drain plug before re;installing. Clean area
round filler plug. Fill transmission to the level of the
filler opening.
The exact amount of oil will depend on the
transmission inclination. In every instance, fill to the
level of the filler opening. Do not overfill; this will
cause oil to be forced out of the case past the
mainshaft and input shaft seals.

1. Max. Operating Angle

2. Transmission Mounting Angle
3. Percent of grade

Adding Oil
It is recommended that different types and brands
of oil are not intermixed because of possible
incompatibility.

Operating Temperature
It is important that the transmission operating
temperature does not exceed 120C for an
extended period of time. Operating temperatures
above 120C will cause breakdown of oil and
shorten transmission life.
The following conditions in any combination can
cause operating temperatures of over 120C:
1. Operating consistently at road speeds under
32 km/h (20 m.p.h.)

Anytime the transmission operating angle of 12 is

exceeded for an extended period of time the
transmission should be equipped with an oil pump
or cooler kit to ensure proper lubrication.
Note the effect low oil levels can have on safe
operating angles. Allowing the oil level to fall 13
mm (0,5 in) below the filler plug hole reduces the
degree of grade by approx. 3 (5,5%).

Towing
When towing the vehicle, the propeller shaft
between the axle and transmission must be
disconnected.

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General

Recommended Lubricants
Only use recommended lubricants to ensure smooth running.

Lubrication Change and Inspection

Highway Use
First 8,000 km

Change transmission oil on new units

Every 16,000 km

Inspect oil level. Check for leaks.

Every 80,000 km

Change transmission oil

Off Highway
First 30 hours

Change transmission oil on new unit

Every 40 hours

Inspect oil level. Check for leaks

Every 500 hours

Change tranmission oil when severe dirt conditions exist

Every 1,000 hours

Change transmission oil (normal off-highway use)

Change oil filter element, if so equipped, at each oil change

Type

Quality

Temperature

Heavy Duty Engine Oil to Specification

SAE 50

over -12C

MIL-L-2104C or MIL-L-46152

SAE 40

over -12C

or API-SC or API-CC

SAE 30

under -12C

Mineral Gear Oil to Specification

SAE 90

over -12C

API-GL-1

SAE 80 W

under -12C

Mild EP Gear Oil* to Specification

SAE 90

from -12C to 38C

MIL-L-2105 or API-GL-4

SAE 80 W

from -26C to 21C

Multi-purpose Gear Oil* to Specification

SAE 85 W 140

over -12C

MIL-L-2105B or MIL-L-2105C
or API-GL-5

SAE 80 W 140
SAE 90

over -26C
from -12C to 38C

SAE 80 W 90

from -26C to 38C

SAE 80 W

from -26C to 21C

SAE 75 W

from -40C to -26C

* These oils are NOT recommended when lubricant operating temperatures are above 110C.
Note: Synthetic oils are NOT recommended.

1/4

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General

Torque Tightening Recommendations

Screws and Nuts
1. All 1/8" Compression Fittings. 7 to 10 Nm.
2. Clutch Housing. 4 Capscrews M12 Thread.
Aluminium Housing: 84 to 96 Nm with Shakeproof
Internal Lockwasher.
Cast Iron Housing: 96 to 109 Nm with Spring
Lockwashers.
3. Clutch Housing. 6 Nuts M16 Thread.
Aluminium Housing: 190 to 203 Nm with Plain
Washer and Nylon Locking Nut.

8. Shift Bar Housing. 16 Capscrews M10 Thread 53 to 66 Nm. Thread coated with Loctite.
9. Air Filter Bracker. 2 Capscrews M10 Thread - 53
to 66 Nm Spring Lockwashers.
10. Filter Pressure Regulator and Pulse Unit. 2
Capscrews M6 Thread - 11 to 16 Nm. With Spring
Lockwashers and Plain Nuts.
11. Output Shaft. Nut 2" - 16 Thread- 610 to 680
Nm. With Nyon Locking Insert or Staking Collar.
Ensure nut is securely staked into the shaft groove.

Cast Iron Housing: 244 to 270 Nm with standard

Nut and Spring Lockwashers.

4. Clutch Housing. 6 Studs - M16 Thread minimum 81 Nm, driven until bottomed. Installed
with Loctite 270.
5. Input Shaft Front Bearing Cover. 6 Capscrews
M10 Thread - 53 to 66 Nm. Thread coated with
Loctite 270.
6. 5 Yoke Lockscrews. 7/16" - 20 Thread - 47 to
61 Nm secure with Lockwire.

12. Auxiliary Housing. 17 Capscres M10 Thread 53 to 66 Nm. Spring Lockwashers.

13. Splitter Cylinder Yokes. 2 Yoke Screw 7/16" 20 Thread -47 to 61 Nm. Secure with Lockwire.
14. Oil Drain Plug. 3/4" Pipe Thread, 61 to 75 Nm.
15. Reverse Idler Shafts. 2 Capscrews M10 Thread
- 53 to 66 Nm. Thread coated with Loctite.

7. Shift Lever Remote Control Housing Studs. 4

M10 Thread - 53 Nm, driven until bottomed.
(Note: Style of Nuts and Washers will vary with
specification.)

1/5

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General

Plunger in Reverse Yoke

1. After installing Plunger and
Spring, tighten Plug and back
off 1/4 to 1/2 Turn. Stake
Threads in Hole.
N.B. Not fitted on SAMT
transmissions.

1. 4 Support Studs. M16 Thread - minimum 81

Nm. Drive until bottomed, installed with Loctite 270.
2. 4 Support Studs Nuts. M16 Thread - 230 to
250 Nm oiled at vehicle location, with Lockwashers.
3. Air Filter Plug. 11/4" - 18 Thread - 23 to 28,5
Nm.
4. Auxiliary Countershaft Rear Bearing Cover.
11 Capscrews M10 Thread - 53 to 66 Nm. Thread
coated with Loctite 270.
5. Oil Filler Plug. 11/4" Pipe Thread - 81 to 102
Nm.

12. Speedometer Housing. 1 Capscrew M10

Thread - 53 to 66 Nm, with Brass Flatwasher and
Nylon Seal.

6. Lower P.T.O. Cover. 8 Capscrews M12 Thread 96 to 109 Nm. Thread coated with Loctite,
Lockwashers.

13. Speedometer Housing. 5 Capscrews M10

Thread - 53 to 66 Nm, Lockwashers.

7. Splitter Cylinder Cover. 4 Capscrews M10

Thread - 41 to 47 Nm. Thread coated with Loctite.
8. Cover - Clutch Housing. 4 Capscrews M8
Thread - 29 to 34 Nm.
9. Plug. 9/16 - 18 Thread - 47 to 68 Nm.

14. Speedometer Housing Plug. 47 to 61 Nm.

15. Upshift Brake. 2 Capscrews & 4 Socket head
M10 Thread - 53 to 66 Nm.
1 Capscrew (on Keep Plate) M12 Thread - 95,0 to
102,0 Nm.
2 C/S Screws M8 Thread - 17,0 to 21,0 Nm.

10. Side Power Take Off Cover. 6 Capscrews

M10 Thread - 53 to 66 Nm. Thread coated with
Loctite.
11. Plug. 1/4" Pipe Thread - 13 to 16 Nm.

1/6

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General

Disassembly Precautions

Inspection of Expendable Parts

It is assumed in the detailed disassembly

instructions that: The lubricant has been drained.
The necessary linkage and air lines removed from
the chassis. Removal of the gear shift remote
control housing assembly is included in the detailed
instructions; however, this assembly must also be
removed from transmission before removing unit
from vehicle.

Before reassembling the transmission, the

individual parts should be carefully checked to
eliminate those damaged. They should be
renewed. This inspection procedure should be
carefully followed to ensure the maximum of wear
life from the rebuilt unit.

Follow each procedure closely in each section,

making use of both the text and the pictures.
1. Cleanliness - Provide a clean place to work. It is
important that no dirt or foreign material enters the
unit during repairs. The outside of the unit should
be carefully cleaned before starting the
disassembly. Dirt is abrasive and can damage
bearings.
2. Bearings - Carefully wash and relubricate all
bearings as removed and protectively wrap until
ready for use. Remove bearings with pullers
designed for this purpose.

The cost of a new part is generally a small fraction

of the total cost of downtime and labour, should the
use of a questionable part make additional repairs
necessary before the next reguarly scheduled
overhaul.
Recommended inspection procedures are set forth
in the following check list:

A. Bearings
1. Wash all bearings in clean solvent. Check balls,
rollers and races for pits and spalled areas. Renew
damaged bearings.
2. Lubricate undamaged bearings and check for
axial and radial clearances. Renew bearings with
excessive clearances.

3. Assemblies - When disassembling the various

assemblies, such as the mainshaft, countershaft
and shift bar housing, lay all parts on a clean
bench in the same sequence as removed. This
procedure will simplify reassembly and reduce the
possibility of losing parts.

3. Check fits of bearings in housing bores. If outer

races turn too freely in the bores, the housing
should be renewed. Check housing bores for signs
of wear prior to taking this action. Only replace
housing if wear is seen as a result of bearing spin.

4. Snap rings - Remove snap rings with pliers

designed for this purpose. Rings removed in this
manner may be reused, except where new ones
are specified in 'Reassembly'.

B. Gears

5. Input shaft - The drive gear or input shaft can

be removed without removing the countershaft or
mainshaft. Take care not to misplace or lose the
mainshaft spigot thrust races and washers.

2. Check all engaging gear teeth. Gears with teeth

worn, tapered or reduced in length from clashing in
shifting should be renewed.

1. Check gear teeth for pitting of the tooth faces.

Gears with pitted teeth should be renewed.

6. When Pressing - Apply force to shafts, housings

etc. with restraint. Movement of some parts is
restricted. Do not apply force after the part is
restricted. Do not apply force after the part being
driven stops solidly. Use soft hammers and bars for
all disassembly work.

3. Check axial clearances of gears. Where

excessive clearance is found, check gear snap
ring, washer, spacer and gear hub for excessive
wear.
Maintain 0.13 to 0.30 mm axial clearance on
mainshaft forward gears and on reverse gear.

C. Bearing Sleeve - Mainshaft

1. Sleeves with groove formation, pits or which
have either been overheated or worn out must be
renewed.
2. Radial clearance between bush and shaft should
be 0.76 mm to 1 mm.

1/7

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General

D. Splines

K. Bearing Covers

1. Check splines on all shafts for wear. If sliding

clutch gears, output drive flange or clutch hub have
worn into the sides of the splines, the shafts in this
condition must be renewed.

1. Check covers for wear from thrust. Renew

covers worn of grooved from thrust of bearing outer
race.

E. Thrust Washers

2. Check bores of covers for wear. Renew those

worn oversize.

1. Check surfaces of all thrust washers.

L. Oil Return Threads and Seals

Washers scored or reduced in thickness should be

renewed.

1. Check oil seal in front bearing cover for damage

and wear, renew if necessary.

F. Reverse Idler Gear

2. Check oil seal in speedometer housing for

damage or wear, renew if necessary. Renew grit
shield if worn or loose on flange.

1. Check bearing sleeve for wear from action of

roller bearings.

M. Sensor/Jaw Clutches

G. Grey Iron Parts

1. Check all grey iron parts for cracks and breaks.
Renew or repair parts found to be damaged. Heavy
castings may be welded or brazed providing the
cracks do not extend into bearing bores or bolting
surfaces.

H. Clutch Release Parts

1. Check clutch release parts, yokes and bearing
carrier. Check pedal shafts. Renew worn shafts and
bearings.

I. Shifting Bar Housing

1. Check yokes and gates for wear at contact
points. Renew worn parts.
2. Check yokes for alignment.

1. Check the sensors and jaw clutches for burrs,

uneven and excessive wear at contact surface, and
metal particles. Check the 'gylon' faces for wear or
damage.
2. Check energiser rings for excessive wear or loss
of tension. Renew if in any doubt.
3. Check sensor contact surfaces on the gears for
excessive wear. If burnt out contact surfaces are
evident, gears should be renewed.

N. Sliding Clutches
1. Check all yokes and yoke slots in sliding
clutches for extreme wear or discolouration from
heat.

3. Check yokes for excessive wear, renew worn

yokes.

2. Check engaging teeth of sliding clutches for

partial engagement pattern. Clutches with engaging
teeth worn, tapered or reduced in length from
clashing should be renewed.

4. Check lockscrews in yokes and gates. Tighten

and re-wire those found loose. Lockscrews with
worn tapers must be renewed.

O. O-Rings
1. Renew all O-rings.

5. If housing has been dismantled, check neutral

notches of shifting bars for wear from interlock
balls. Bars indented at points adjacent to the
neutral notch should be renewed.

J. Gear Shift Remote Control

1. Check spring tension on shift shaft. Renew
tension spring if shaft moves too freely.
2. If housing is dismantled, check shift shaft and
finger and the sliding bearings for wear. Renew
worn parts.

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General

Reassembly Precautions
bearing, preventing damage to balls and races and
maintaining correct bearing alignment with shaft
and bore. A Tubular type driver, if used, will apply
force only to the inner race.

Make sure that interiors of all housings are clean. It

is important that dirt be kept out of transmission
during reassembly. Dirt is abrasive and can
damage polished surfaces of bearings and
washers. Use certain precautions, as listed below,
during reassembly.

7. Output Shaft Drive Flange - Replace any

flanges with worn or damaged seal journals.
Secure the flange by torqueing the nut to 610 to
680 Nm.

1. Gaskets - Use new gaskets throughout the

transmission as it is being rebuilt. Make sure all
gaskets are installed, as omission of a gasket can
result in oil leakage or misalignment of bearing
covers.
2. Capscrews - To prevent oil leakage, use thread
sealant on all capscrews. The corresponding torque
ratings are to be found in 'Torque
Recommendations for Screws and Nuts'.
3. O-Rings - Lubricate all O-rings lightly with
silicone lubricant.

If the nut is a staked nut, ensure that nut is

adequately staked into the groove on the shaft.
Failure to do this allows the shaft to move axially
resulting in damage to the bearing and mainshaft
thrust races.
Prior to refitting a flange (or yoke) ensure that the
seal track is not grooved scored or pitted. If in
doubt, it must be replaced.

4. Initial lubrication - Stick mainshaft thrust race

packs onto mainshaft spigots with petroleum jelly to
assist in preventing them becoming displaced
during reassembly.
5. Axial Clearances - Maintain the axial
clearances of mainshaft forward speed and reverse
gears at 0.13 to 0.30 mm.
6. Bearings - Use of flange-end bearing drivers is
recommended for the instalation of bearings. These
drivers apply equal force to both races of the

1/9

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General

Special Tools
Some illustrations show the use of specialised tools. These tools are recommended for disassembly and
reassembly of the transmission. They make repair easier, faster and prevent damage.
The following tools are available from SPX UK (Ltd) Tel : +44 (0)1327 704461

LC105A Main Tool Assembly

LC 204 Dummy Support - Countershaft Rear

Journal

E 105-1 Adaptor Auxiliary Countershaft Rear

Bearing

E 108 Installer Main Tool

E 105-2 Adaptor Countershaft Front Bearing

E 108-1 Countershaft Front Bearing Installer

E 105-3 Adaptor Countershaft Rear Bearing

E 108-2 Output Shaft Bearing Installer

1/10

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General

E 108-3 Countershaft Rear Bearing Installer

E 109-3 Input Shaft Bush and Output Shaft Bush

Installer

E 108-4 Oil Seal Installer

E 108-5 Auxiliary Countershaft Bearing and Input

Shaft Bearing Installer

E 113 Jaw Clutch Spring Compressor

E 109 Handle - Installer

LC 284/11 Rev Idler Shaft Puller Adaptor

E 109-1 Rev Idler Bearing Installer

MS 284 Slide Hammer

1/11

5/01

Section 2

Air System

5/01

Air System
General Description
Twin Splitter 12 speed
A = Main section

B = Auxiliary section

The Twin Splitter Transmission has a 4 speed main section with an auxiliary section containing 3 splitter
ratios

Main section

Auxiliary section
I Low
II Intermediate
III High

4 forward speeds
1 reverse speed
Gear shift by means
of shift lever

Each forward gear is split

three times, giving twelve
gears in total

Pneumatic gear shift

by means of a splitter
switch

Air System Maintenance

In order to ensure that the transmission functions
without problems and has a long life, the
compressed air reservoirs on the vehicle must be
drained regularly and the filter on the transmission
cleaned every 80,000 kms (or 6 months). Please
consult the Operating Instructions supplied by the
vehicle manufacturer.

2/1

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Air System

Twin Splitter Single 'H' Pattern

Gearshift

Single 'H' pattern gate, four position plus reverse, three splitter gears available in each position.

Splitter

I Low
II Intermediate
III High

Three position flick-switch, Low (I), Intermediate (II) and High (III), for pre-selection of splitter gears
engaged through throttle operation or clutch control.

2/2

5/01

Air System

Splitter System - Signal Connections

Switch
Port
No.
1
3
21
22
23

Transmission Connections
Overdrive
Filter/Regulator
Exhaust
Shift Cover 'R'
Shift Cover 'F'
Blank Off

Direct
Filter/Regulator
Exhaust
Shift Cover 'R'
Blank Off
Shift Cover 'F'

Splitter Switch - Signal Pipe Connections

1. Splitter Switch Signal Connection

Transmission Air Connections - Upshaft Brake and Splitter Cylinder

1. 3 Way Pilot Valve to be operated only when the clutch is fully depressed
2. Pulse Unit Supply (5.5 bar)
3. 'R' Port and 'F' Port (shift cover)
4. Air Supply (7-8 bar)
5. Regulated Air (5.5 bar)

2/3

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Air System

Filter Pressure Regulator

Filter Maintenance

1. Filter pressure regulator

6. Plug

2. Filter element

7. Air supply port

3. Seal ring

8. Outlet port *

4. 'O' ring

9. Outlet seal plug *

5. End cap

10. Capscrew with lockwasher

.A. Removal and Disassembly

B. Assembly and Installation

1. Remove end cap

1. Renew filter element, seal ring and O ring if

necessary.

2. Remove filter insert from housing and clean.

Cleanser: Soap and water solution, cold cleaner
etc. Then blow element from inside using
compressed air.
3. Clean filter regulator housing.

2. Fit end cap.

3. Check filter regulator function. Unscrew seal plug
(9), attach test connection with gauge.
Recommended operating pressure 5.34-5.69 bar.

* Alternative positions

2/4

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Air System

Selector Switch
Splitter Ratios

I. Low
II. Intermediate
III. High

Function
Constant air supply to '1' from filter/regulator.

Shift Position I

Overdrive

Direct

Air supply from 21 to shift cover

Air supply from 21 to shift cover 'R'

'R' and from 22 to shift cover 'F'.

Shift Position II

Air supply from 22 to shift cover 'F'.

No air supply from valve in this position.

Shift Positon III

No air supply from valve in this

Air supply from 23 to shift cover 'F'.

position.

2/5

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Air System

Selector Valve Removal and Re-fitment

Removal and Disassembly

1. Remove cowl.
2. Disconnect all air lines.
3. Loosen lock nut and unscrew selector valve from
shift lever.
4. To disassemble the valve remove socket head
screw (2).
Note: Take care not to break tang from cap.
5. Thoroughly clean inside of selector valve.

Re-fitment
1. Renew seal ensuring that it is fitted correctly.
2. Smear sealing surface of base using lubricant
supplied in Service Kit.
Caution: Do not use any other type of lubricant.
3. Reassemble valve and tighten socket headed
screw to the correct torque.
4. Screw selector valve onto shift lever and secure
with lock nut.
1. Cowl
2. Socket head screw

Note: Only screw down max. 17mm, otherwise the

housing will be deformed and the valve will leak.

3. Base

5. Connect all air lines and test for leaks.

4. Seal

6. Refit cowl.

5. Housing

Torque:

6. Pressure pad
7. Anti-rattle spring
8. Plunger

Socket head screw (No.2)

= 10-12 Nm.

Air connection

= 2.7-3.4 Nm.

9. Compression spring
10. Lever

Trouble Shooting Hints

11. Cap

- Check that valve functions correctly.

12. Lock nut

- Check all air connections for leaks.

13. Shift lever

14. max 17 mm
- Lubricant (sachet)

- Remove valve from gear lever and check socket

head screw (No.2) for tightness.
- If leaks persist renew the seal (No.4). (Service
Kit No. T20137).

2/6

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Air System

Upshift Clutch Brake - Pulse Unit

1. 3 Way Pilot Valve to be operated only when the clutch s fully depressed
2. Pulse unit supply 1/8 27 N.P.T.F.
3. Air Supply 3/8 - 18 N.P.T.F.
4. Regulated Air 5.5 bar 1/8 N.P.T.F.

A pulse valve gives a controlled pulse of air to the

upshift brake activated by a pilot valve usually fitted
under the clutch pedal.
When the clutch pedal is fully depressed the pulse
unit is activated, giving a single pulse of air for up
to a maximum of 0.45 second.

Trouble Shooting Hints

In case of suspected failure.
1. Check clutch pedal area of cab to ensure that
the pilot valve is able to operate effectively.
2. Check air supply to pulse unit when clutch pedal
is fully depressed.
3. Disconnect the air connection at the upshift
brake. Fully depress the clutch pedal and check
that a pulse of air is being supplied. If no air is
being supplied, renew the pulse unit.

2/7

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Air System

Splitter shift
Cylinder Operation
Constant air is supplied to the shift cylinder cover
port 'S' from the filter/regulator. Pilot signals (to F
and R) from the splitter switch in the cab cause the
valves on the cylinder cover to supply air to the
pistons. Refer to Table 1 and Figures 1 and 2. The
interlock pin prevents both piston shafts being
selected at the same time.
Fig. 1 Overdrive Transmission

Fig. 2 Direct Transmission

1. Shift Cylinder Cover

1. Shift Cylinder Cover

2. Intermediate

2. High

3. Interlock Pin

3. Interlock Pin

4. Low

4. Low

5. High

5. Intermediate

Table 1
Overdrive
B
C

Direct
B

Splitter/Cylinder

I Low

II Intermediate

III High

P = Pressure, E = Exhaust, see figs, 1 and 2.

2/8

5/01

Air System

Splitter Cylinder Cover Assembly - Logic Valves

The splitter cylinder cover assembly consists of a

cast aluminium housing with internal drillings on
which are mounted three, sealed, air operated logic
valve units.

If signal pressure is applied to port 'F' (and cut off

from port 'R') the 'NOT' unit will open, the left hand
'YES' unit will open, the left hand 'YES' unit will
close and the right hand 'YES' unit will open to give
pressure to port 3 of the splitter cylinder.

All three units are of similar design but perform

different functions. Two units are designated YES
units and the third, a NOT unit.

For individual circuit diagrams, refer to Splitter Air

Circuit Diagrams - Logic Valves: Overdrive
Transmission, Direct Drive Transmission.

The NOT unit is a 'normally open' valve whereby

supply pressure to port 2 (the centre port) holds the
valve open and supplies air straight to output port
3. When a signal pressure supply is applied to port
1 the valve is closed by the opposing air pressure
and port 3 is vented to atmosphere.

The two YES units are identical and each is a

'normally closed' valve whereby the supply
pressure to port 2 holds the valve closed and
prevents air from going to the output port 3 (which
is vented to atmosphere). When a signal pressure
supply is applied to port 1, the opposing air
pressure closes port 3 to atmosphere opens the
valve and air pressure from port 2 is supplied to
port 3.

A constant air pressure to port 'S' supplies ports 2

of both the left hand and right hand 'YES' units and
port 1 of the splitter cylinder.

Fig. 1 Splitter Cylinder Cover Internal Drillings

If signal pressure is now applied to ports 'R' and 'F'

the 'NOT' unit is closed and the left hand 'YES' unit
will open to give pressure to port 2 of the splitter
cylinder.

2/9

5/01

Air System

Splitter Cylinder Cover Assembly - Twin Spool Valves

Twin Spool Valve Unit

The splitter cylinder cover assembly consists of a
cast aluminium housing containing two glandless
sleeve-and-spool valve assemblies. Each sleeve is
supported radially and axially in the cover assembly
in 'O' rings, but there are no seals or 'O' rings fitted
to the valve spool which relies on extremely close
tolerances (1 micron) to form the seal between it
and the sleeve, Internal drillings in the housing
connect the two valves to one another and the
splitter operating cylinder housing.

circuit diagram it will be seen that in TSO low, port

'F' also receives signal pressure but this is shut off
by the lower spool valve and serves no purpose in
this range.

Three ports marked 'S', 'F' and 'R' connect to the

air supply and the splitter selector switch.

When signal air pressure to port 'R' is shut off and

the line exhausted out of port 3 on the splitter
selector switch, the lower spool valve returns to the
right under pressure of the spring. This shuts off
the constant air pressure to port 2 of the splitter
cylinder, exhausts the line and also opens the
signal air supply passage from port 'F' to the upper
spool valve. If signal air pressure is now applied to
port 'F' the upper spool valve is forced to the left
against spring pressure and opens the constant air
supply feed to port 3 on the splitter cylinder.

Port 'S' receives constant air pressure which is

passed to both spool valves and to port 1 of the
selector valve. Ports 'F' and 'R' receive signal
control air supply from the selector switch,
depending on its position.

When signal air pressure is shut off from both 'F'

and 'R' ports, both spool valves are enabled to
return to the right under spring pressure and the
lines vented to atmoshere.

The upper, shorter spool valve has a single

chamber and acts as an ON/OFF switch to port 3
of the splitter cylinder.

The mechanical functions within the transmission

are identical whether a logic valve or a spool valve
assembly is fitted.

The lower, longer, spool valve has two chambers

and performs two functions. The left hand chamber
acts as an ON/OFF switch to port 2 of the splitter
cylinder while the right hand chamber acts as an
ON/OFF switch to control the upper spool valve in
response to signals to ports F and R from the
splitter selector switch.

If signal air pressure is supplied to port 'R' on the

housing, the air pressure forces the lower spool
valve to the left against spring pressure and
uncovers the constant air supply from port 'S' to
give pressure to port 2 of the splitter cylinder. In the

2/10

5/01

Air System

Splitter System - Splitter Gear Air Line Connections

12 Speed Twin Splitter Transmission Models
Overdrive

I.

Splitter Switch Connections

II. Splitter Shift Cylinder

IV. Filter/Regulator
V. Regulated Air (5,5 bar)

III. Filter/Regulator

Direct

I.

Splitter Switch Connections

II. Splitter Shift Cylinder

IV. Filter/Regulator
V. Regulated Air (5,5 bar)

III. Filter/Regulator

2/11

5/01

Air System

Splitter Air Circuit Diagrams - Logic Valves

Overdrive Transmissions
Fig. 1 TSO - Low
1. Filter
2. Regulator
3. Switch
4. Intermediate
5. Interlock Pin
6. Low
7. High
8. Right hand
9. Left hand

Fig. 2 TSO - Intermediate

1. Filter
2. Regulator
3. Switch
4. Intermediate
5. Interlock Pin
6. Low
7. High
8. Right hand
9. Left hand

Fig. 3 TSO - High

1. Filter
2. Regulator
3. Switch
4. Intermediate
5. Interlock Pin
6. Low
7. High
8. Right hand
9. Left hand

2/12

5/01

Air System

Direct Drive Transmission

Fig. 1 TS - Low
1. Filter
2. Regulator
3. Switch
4. High
5. Interlock Pin
6. Low
7. Intermediate
8. Right hand
9. Left hand

Fig. 2 TS - Intermediate
1. Filter
2. Regulator
3. Switch
4. High
5. Interlock Pin
6. Low
7. Intermediate
8. Right hand
9. Left hand

Fig. 3 TS - High
1. Filter
2. Regulator
3. Switch
4. High
5. Interlock Pin
6. Low
7. Intermediate
8. Right hand
9. Left hand

2/13

5/01

Air System

Splitter Air Circuit Diagrams - Twin Spool Valves

Overdrive Transmission

Fig. 1 TSO - Low

1. Low
2. Vent
3. Exhaust
4. Switch
5. Filter
6. Regulator

Fig. 2 TSO - Intermediate

1. Intermediate
2. Vent
3. Exhaust
4. Switch
5. Filter
6. Regulator

Fig. 3 TSO - High

1. High
2. Vent
3. Exhaust
4. Switch
5. Filter
6. Regulator

2/14

5/01

Air System
Direct Drive Transmission

Fig. 1 TS - Low
1. Low
2. Vent
3. Exhaust
4. Switch
5. Filter
6. Regulator

Fig. 2 TS - Intermediate
1. Intermediate
2. Vent
3. Exhaust
4. Switch
5. Filter
6. Regulator

Fig. 3 TS - High
1. High
2. Vent
3. Exhaust
4. Switch
5. Filter
6. Regulator

2/15

5/01

Air System

Splitter Cylinders
Disassembly and Reassembly

2. Carefully install the single piston (with the

shorter shift bar) into the cylinder. Position the
piston so that the slot is aligned with the interlock
pin bore.

(Cylinder removed from transmission)

1. Push or tap out the longer shift bar (with the
double piston) from the splitter cylinder.

3. Install the interlock pin, pushing it fully home and

ensuring that the chamfered end is correctly
aligned into the slot in the piston shaft.

2. Push or tap out the second piston from the

splitter cylinder.

4. Install the inner piston into the second bore,

followed by the outer piston. Push the outer piston
into by bore until flush with the face of the cylinder.

3. Remove the interlock pin.

4. Remove the O rings from the cylinder bores and
the sealing rings from the pistons. Clean all parts.

5. Protect the assembly from ingress of dirt until

ready for reinstallation.

Reassembly
1. Assemble the new O rings into the cylinder bores
using a light application of silicone lubricant,
assemble new sealing rings to the pistons using a
light application of silicone lubricant. Excessive
lubricant causes contamination in the splitter valves
and adversely affects the performance.

Splitter Cylinder Assembly - Exploded View

1.
2.
3.
4.

Splitter Cylinder
Piston
Seal ring
Gasket

5.
6.
7.
8.

Cover assembly
Seal ring
Piston (neutral stop)
Seal ring

2/16

9. Piston
10. Interlock pin
11. O ring
12. O ring

5/01

Air System

Splitter Air Circuit Diagrams - Logic Valves

Troubleshooting Hints
Checking operation of YES and NOT logic valve
units
Each unit is fitted with two, small, coloured
indicator plungers, one red and one green.

To renew a valve unit, remove the two screws and

remove the unit from the splitter cylinder cover
assembly.
Note the position of the location pip when installing
the valve. Always fit new O rings.

These indicators 'pop out' approximately 3,0 mm

upon initial application of air pressure and remain
'out' unless pushed back in by hand for
checking/trouble shooting purposes. In all cases
the Red indicator is on the output port 3, and the
Green indicator on the input signal port 1.
Referring to the air circuit diagram it will be seen
that with air pressure to the supply port 'S' only, all
six indicators on the three logic valve units should
be able to be pushed in.
If signal pressure is applied to port 'F' the Red
indicator on the NOT unit and the Green and Red
indicators on the right hand YES unit should 'pop
out' and feel to be under pressure if an attempt is
made to push them back in.
If signal pressure is now also applied to port 'R' as
well as port 'F; the Green indicator on the NOT unit
and the Green Red indicators on the left hand YES
unit should 'pop out' and felt to be under pressure.
Additionally it should now be possible to push in
the Red indicator on the NOT unit and the Red and
Green indicators on the right hand YES unit. Table
1 indicates the plungers which should be under
pressure when a particular range is selected.

Fig. 1 Splitter Cylinder Cover - Exploded View.

TSO
NOT

L/H YES

R/H YES

Low
Int
High

Green
Red
No

Green/Red
No
No

No
Green/Red
No

Low
Int
High

Green
No
Red

Green/Red
No
No

TS

No
No
Green/Red

Table 1: Logic valve units indicator plunger

checking chart
Air leaks from the valve unit exhaust port(s) could
indicate either a leaking valve unit diaphragm or
valve seat, or a leaking splitter control piston O
ring.

1. Red 2. Green
Fig. 2 Logic valve units indicator plungers.

If the valve unit is at fault it must be renewed

2/17

5/01

Section 3

Shifting Controls

5/01

Shifting Controls
Shift Bar Housing - Single 'H' Shift
Remote Control (LRC) - Single 'H' Shift - Exploded View

1. Remote Control LRC

2. Housing
3. Gasket
4. Sliding Bearing
5. Housing Cover, rear
6. Reaction Rod Bracket
7. Capscrew
8. Washer
9. Spring
10. Shaft with Shift Finger
11. Washer
12. Stop Ring
13. Locking Pin
14. Stop Sleeve

3/1

15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.

Gasket
Housing Cover, front
Capscrew
Sliding Bearing
Seal Ring
Bellows
Pinch Bolt
Lever
Locknut
Ball Joint
Reaction Rod Ball Joint
Locknut
Reaction Rod
Link

5/01

Shifting Controls
A. Disassembly of Remote Control (LRC)

1. Remove the remote control from the shift bar

housing, remove the shift lever and reaction rod

4. Drive out the locking pin from the stop ring.

2. Remove the housing front cover.

5. Remove the stop ring, spring and lockwasher.

3. Remove the stop sleeve from the housing front

cover.

6. Manoeuvre the shift shaft and finger out of the

housing. Remove the housing rear cover and
reaction rod bracket.

3/2

5/01

Shifting Controls
B. Reassembly of Remote Control (LRC)

7. If necessary renew the sliding bearings and the

seal ring in the housing front cover.

10. Drive in a new stop ring lock pin.

8. Fit the housing rear cover and reaction rod

bracket. Install the shift shaft and finger into the
housing.

11. Install the stop sleeve into the housing front

cover.

9. Assemble the lockwasher, spring stop washer

and stop ring over the shaft.

12. Install the housing front cover. Refit the shift

lever and reaction rod and install the remote
control onto the shift bar housing.

3/3

5/01

Shifting Controls
Shift Bar Housing Assembly - Exploded View

1.
2.
3.
4.
5.
6.

Plug/Neutral Switch
Plug/Reverse switch
Detent balls (3)
Detent springs (3)
Capscrew (2)
Lifting eye

7. Actuating pin
8. Plug - (oil pump or cooler
feed)
9. Plug - (breather)
10. Shift bar housing
11. Gasket
12. Capscrew (14)
13. Gasket
14. Gasket
15. Stud
16. Gasket
17. Plug
18. Spring

3/4

19. Plunger
20. Reverse gear shift yoke
21. Lockscrew
22. 1st/2nd gear selector block
23. Lockscrew
24. 3rd/4th gear selector block
25. Lockscrew
26. 3rd/4th gear selector block
27. Interlock ball
28. Interlock pin
29. 1st/2nd gear shift bar
30. Reverse gear shift bar
31. 1st/2nd gear shift yoke
32. Lockscrew
33. Lockscrew
34. 3rd/4th gear shift yoke
35. Actuating plunger - neutral switch
Not fitted on SAMT transmissions

5/01

Shifting Controls
A. Removal and Disassembly

1. Make sure that the shift bars are in the neutral

position. Remove the three detent springs.
Remove the retaining capscrews and lift off the
shift bar housing. Invert the housing and release
the detent balls by tapping the housing lightly.

3. Remove the 1st/2nd selector block lockscrew

slide the yoke with the bar into the aperture and
remove the yoke lockscrew (from the top side of
the housing). Remove the block, bar gate and
yoke. As the notch clears the housing remove the
interlock pin from the shift bar.

2. Mount the housing in a vice fitted with protected

jaws, rear end of housing to the left. Cut and
remove all lockwires. Remove the reverse yoke
lockscrews and remove the reverse shift bar and
yoke.

4. Remove the 3rd/4th selector block and yoke

lockscrews, remove the yoke. Slide the shift bar
out to the right collecting the two interlock balls.

3/5

5/01

Shifting Controls
B. Reassembly and Installation

5. As the shift bar clears the actuating plunger

boss, remove the actuating plunger, spring and
retaining cup.

1. If previously removed, install the reverse stop

plunger in the reverse yoke. Ensure that the
plunger is fully seated in the bore.

Note: These parts are not fitted on SAMT

transmissions.

6. If necessary support the reverse yoke in the vice

and remove the reverse stop plunger plug.

2. Install the spring in the bore and on the plunger.

Caution: The plug is under spring pressure.

Note: Plunger and spring are not fitted in the
SAMT transmission.

3/6

5/01

Shifting Controls

3. Install the plug. Tighten the plug until flush with

the yoke then unscrew 1 to 1 1/2 turns. Stake the
plug threads through the hole in the yoke to
secure.

5. Push down the actuating plunger and install the

reverse gear shift bar and yoke. Tighten the
lockscrew to the correct torque and lockwire to
secure.

4. Mount the shift bar housing in the vice, rear end

of the housing to the right i.e. the opposite way to
disassembly. Install the neutral switch actuating
plunger, spring and spring retaining cup.

6. Install one of the interlock balls in the housing

bore. Ensure that the reverse shift bar is in the
neutral position and that the ball is resting in the
neutral notch in the bar.

3/7

5/01

Shifting Controls

7. Insert the 1st/2nd gear shift block and shift bar

into the housing. Insert the shift bar from the right.
Install the yoke on the bar, larger offset to the left.

9. Install the second interlock ball.

8. Insert the interlock pin into the bar using grease

to hold it in place, and push the bar through until
the yoke lockscrew can be installed. Tighten the
lockscrew to the correct torque and lockwire to
secure. Slide the yoke and bar to the neutral
position and install the block lockscrew. Tighten to
the correct torque and lockwire to secure.

10. Install the 3rd/4th gear shift bar and block.

Install the yoke, longer offset to the right. Tighten
the lockscrews to the correct torque and lockwire
to secure. Check to ensure interlock only allows
one shift yoke to move at a time and remove the
housing from the vice.

3/8

5/01

Shifting Controls

11. Install the three detent balls into the shift bar
housing bores.

13. Install the retaining capscrews and lifting eyes.

Note the position of the lifting eyes and the
corresponding longer capscrews. Note: It is
essential that the long capscrews are installed in
the correct positions or they may otherwise jam on
the countershaft gear teeth. Tighten the capscrews
to the correct torque.

12. Ensure the sliding clutches and the shift yokes

are in the neutral position and install the shift bar
housing and gasket on to the main transmission
housing.

14. Ensure all the shift bars are in neutral and

install the three detent springs in the bores.

3/9

5/01

Section 4

Main Transmission

5/01

Main Transmission
A. Removal/Disassembly of Auxiliary Section
Caution: Drain Gear Oil
Note: The overdrive auxiliary section is shown in the following steps. The procedure is the same for the
direct version except that the actual gear sizes in respect to the number of teeth on each gear will differ
from these illustrated. In order to avoid confusion between the functions of any particular gear in the
auxiliary section of either model, i.e. high/low/intermediate/overdrive, the splitter gears installed on the
main shaft will be referred to by their relative positions, not their functions.

1. Remove the shift bar housing assembly.

Remove the lockwire and lockscrew from the
splitter yoke.

3. Disconnect the air hose from the splitter valve

and remove the regulator and hose.

Caution: Take care not to allow the lockscrew to

drop into the case

2. Insert two wooden wedges between the reverse

gear and the housing webs. This is to prevent the
mainshaft moving backward allowing the front
thrust race pack to be dislodged.

4. Remove the speedometer drive pinion. Engage

two gears in the main transmission and low (if not
already engaged) in the auxiliary section. Slacken
but do not remove the flange securing nut.

Note: On SAMT transmissions, the speed

transducers must be removed from the
transmission case.

4/1

5/01

Main Transmission

5. Remove the lower (right-hand) auxiliary

countershaft rear bearing cover. Remove the upper
(left-hand) auxiliary countershaft rear bearing
cover/PTO cover. Remove the snap rings from the
rear of both auxiliary countershafts.

8. Remove the snap ring from the bearings.

Remove both bearings using the special puller
engaged into the snap ring groove.

6. Remove the bearing spacers from the rear of

both auxiliary countershafts.

9. Remove the auxiliary housing retaining bolts

(Note the positions of the two longer bolts). Using
three M10 x 37mm bolts into the three threaded
holes as pullers, jack the auxiliary housing away
from the main case.

7. Using a suitable lever, prise both auxiliary

countershafts rearward to expose the snap rings on
the two rear bearings.

10. Attach the special lifting bracket and using a

hoist remove the auxiliary housing.
Note: Guide the centre gear cluster yoke off the
selector bar as the housing is removed.

4/2

5/01

Main Transmission

11. Remove the mainshaft rear thrust bearing pack

(one standard washer, one thrust race and one
graded washer OR one vespel washer and one
graded washer) from the mainshaft rear spigot.

14. Push the centre gear cluster forward and

remove the centre jaw clutch.

12. Using the jaw clutch spring compressor remove

the snap ring from the rear of the mainshaft.

15. Remove the centre gear cluster selector yoke.

13. Remove the rear jaw clutch and spring from

the mainshaft.

4/3

5/01

Main Transmission

16. Slide the centre gear cluster rearward again

approximately 25mm. Slide the upper (left-hand)
auxiliary countershaft rearward approximately
12mm.

18. Lift out the lower (right-hand) auxiliary

countershaft. Remove the support rod. Slide out
the upper (left-hand) auxiliary countershaft.
Remove the snap ring from the mainshaft.

Lay a 20mm diameter rod (arrowed) under the

lower (right-hand) auxiliary countershaft and push
it into the hole in the casing web. Slide the
auxiliary countershaft rearward until clear of its
front bearing and support it on the rod.

19. Using the jaw clutch spring compressor tool,

compress the spring and remove the front jaw
clutch retaining snap ring. Remove the jaw clutch,
spring and spring retainer.

17. Carefully manoeuvre the centre gear cluster

out between the teeth of the two auxiliary
countershafts and remove it from the housing.
Note: A snap ring on the mainshaft will restrict the
gear cluster from sliding along it easily during
removal.

4/4

5/01

Main Transmission
B. Removal and Disassembly of the Output shaft and Auxiliary Section Rear
Sliding Gear
1. Bush

8. Outer bearing cone and rollers

2. Output shaft

9. Speedometer drive gear

3. Inner bearing cup

10. Grit shield

4. Inner bearing cone and rollers

11. Output drive flange

5. Inner spacer

12. Flange retaining nut

6. Outer spacer

13. O-ring

7. Outer bearing cup

1. Remove the lockwire and lockscrew from the

lower selector yoke. Withdraw the yoke and the
rear sliding gear from the output shaft.

2. Remove the splitter valve and actuating cylinder

taking care not to damage the mating faces.
Protect valve and cylinder from dirt, grease and oil.

4/5

5/01

Main Transmission

3. Remove the flange retaining nut, lift off the

flange and grit shield. Remove the cap screws
securing the oil seal and pinion housing. Note the
position of the two special bolts. Lift off the
housing. If necessary drift out the oil seal

6. Remove the two taper roller bearing cups and

the outer spacer from the auxiliary housing.

4. Lift off the speedometer drive gear.

7. Using the auxiliary rear sliding gear as a

support, press the output shaft through the bearing
cone and roller assembly.

5. Press or drift out the output shaft

8. Remove the spigot bush from the output shaft

using a suitable internal extractor.

4/6

5/01

Main Transmission
C. Auxiliary Countershaft Bearing
Renewal

D. Auxiliary Section Splitter Gears

and Sensor Disassembly
Note: The three sensors, one in each of the three
splitter sliding gears are identical in all respects.
Unless they are all to be renewed it is essential
that each assembly is kept separate for
reinstallation in the same sliding gear from which it
was removed.
Note: The centre sliding gear clusters consist of
two separate gears which are assembled together
in production. They cannot be separated in service.

1. When fitted, remove the snap ring and remove

the bearing tracks using a suitable puller. If a snap
ring groove is not provided on the front end of the
shaft, the bearing track is retained with Loctite.
Carefully heat the bearing track if necessary to
deactivate the Loctite.

1. Using suitable circlip pliers remove the sensor

retaining snap ring. Lift out the sensor. (Centre
gear cluster illustrated).

2. Apply a thin bead of Loctite 601 to the auxiliary

countershaft front bearing spigot. (On shafts with a
circlip groove machined on the front bearing spigot,
the snap ring may be omitted if Loctite is used.)

3. Heat the new front bearing inner track to a

maximum of 135C and place it on the auxiliary
countershaft, shouldered side towards the gears.

2. Remove the energiser ring from the sensor

using angled grips or pliers

4/7

5/01

Main Transmission
E. Splitter Gears Reassembly
Splitter Sliding Gears and Jaw Clutches - Exploded View.
1. Spring retainer
2. Spring (short)
3. Jaw clutch
4. Energiser ring
5. Sensor
6. Yoke
7. Centre sliding gear
8. Sensor
9. Retaining snap ring
10. Jaw clutch
11. Spring (long)

12. Jaw clutch

13. Sensor
14. Yoke
15. Rear sliding gear
16. Mainshaft snap ring

1. Mount the sensor in the vice as illustrated. Insert

the new energiser ring into the groove, overlapping
part at the bottom. Using two screwdrivers expand
the ring until the ends abut and snap into the
groove.

4/8

2. Place the sensor in the sliding gear (centre gear

cluster illustrated) and fit the retaining snap ring.

5/01

Main Transmission
F. Rear Sliding Gear and Output Shaft
Reassembly and Installation

1. Support the shaft and using a suitable installer

and mallet drive in the new bush until fully home
against the shoulder.

3. Heat both output shaft bearing inner cones and

roller assemblies to a maximum of 135C before
installation. Install the (heated) front bearing cone
and roller assembly on to the shaft against the
splined flange. Install the inner spacer against the
bearing.

2. The output shaft bearing and spacers are a

matched set. All six items are etched with a serial
number (i.e. 84/21994). Both parts of one of the
bearings are marked with the suffix A. It is
essential that these parts are assembled together,
and that all parts carry the same serial number

4. Stand the output shaft, with the assembled

bearing on a wood block approximately 50mm
thick. Place the housing over the shaft.

4/9

5/01

Main Transmission

5. Drive the outer cup of the inner bearing conical

face downwards into the auxiliary housing. Install
the outer spacer with the lubricating oil hole
aligned with the hole in the housing bore, and the
outer bearing cup, shoulder uppermost, on the
inner bearing cup. Drive all three parts into the
housing bore.

7. If previously removed install a new oil seal, flat

face uppermost, into the speedometer housing.

6. Install the (heated) outer bearing inner cone and

roller assembly over the shaft against the spacer.
Make sure that the outer bearing cup shoulder
abuts the housing and the bearing fits closely.

8. Place the speedometer drive gear over the

output shaft. (If a speedometer drive gear is not
fitted, a spacer of equivalent thickness must be
installed.)

4/10

5/01

Main Transmission

9. Place the speedometer housing and gasket on

the auxiliary housing, and insert the speedometer
pinion into the housing. Ensure that speedometer
housing is correctly positioned.

11. Locate the plastic grit shield on to the output

drive flange, dished face away from the flange. Do
not push fully on to the flange. Install the flange
and grit shield onto the output shaft.

10. Install the capscrew and tighten to correct

torque.

12. Install a new self-locking nut and tighten to the

correct torque. Rotate the shaft as the nut is
tightened to ensure that the bearings are correctly
seated. Finally ensure that the nut is adequately
staked into the output shaft groove.

Note: Install the capscrew adjacent to the

speedometer pinion with a new nylon washer.

4/11

5/01

Main Transmission

13. Put timing marks on the rear sliding gear (in

preparation for installation of rear housing to main
case). Paint any two adjacent teeth and then the
two teeth directly opposite the first two.

14. Place the selector cylinder into the rear of the

auxiliary housing.

16. Install the rear sliding gear on to the output

shaft, sensor facing forward. Install the selector
yoke into the groove in the sliding gear and onto
the lower selector piston bar.

17. Install the lockscrew and tighten to the correct

torque. Lockwire to secure.

15. Secure the selector cylinder together with the

splitter valve, using new gaskets, to the rear of the
housing. Tighten the capscrews to the correct
torque.

4/12

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Main Transmission
G. Main Section Disassembly

1. Remove the input shaft cover. Note the position

of the two capscrews with drilled heads. (Push
type clutch release bearing only).

4. Remove the snap rings from the front of both

countershafts.

2. Grasp the input shaft firmly and joggle the shaft,

gear and bearing out of the housing. Retain the
parts in order for the reassembly.

5. Remove the snap rings from the rear of both

countershafts.

3. Remove the mainshaft thrust washers and the

3rd/4th gear sliding clutch from the mainshaft.

6. Using a pry bar remove the two auxiliary

countershaft front bearings from the housing.

4/13

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Main Transmission

7. Remove the left-hand (upper) reverse idler gear

shaft support washer.

10. Remove the reverse gear retaining snap ring

from the mainshaft. Remove the plain spacer and
the large internally splined spacer.

8. Tap the idler gear shaft forwards approximately

10mm and remove the circlip from the front end of
the shaft.

11. Remove the wedges and slide the reverse gear

rearward on the shaft. Using a probe push the
internal spacer in the gear forward and carefully
prise out the snap ring.

9. Using a slide hammer screwed into the rear of

the shaft, withdraw the shaft. Roll the reverse idler
gear away from the mainshaft (the washer will drop
into the case).

12. Slide the reverse gear forward onto the reverse

sliding clutch and against 1st gear. Remove the
spacer and the graded washer.

4/14

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Main Transmission

13. Slide the complete mainshaft rearwards in the

housing. Using a soft drift and heavy mallet drive
the right-hand (upper) countershaft rearward
approximately 5mm (max) through the front
bearing. Drive the countershaft forward again, from
the rear, to expose the snap ring around the front
bearing.

16. Using the special puller remove rear bearing

from the countershaft.

17. Using suitable wooden blocks in the front and

rear bearing bores block the countershaft away
from the mainshaft.

14. Remove the snap ring and assemble the

special puller into the snap ring groove. Remove
the bearing from the shaft and housing.

15. Using a soft faced mallet drive the countershaft

rearwards again until the rear bearing is clear of its
bore in the housing.

18. Lift the mainshaft assembly from the housing.

4/15

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Main Transmission

19. Remove the reverse idler gear and the idler

gear washer from the housing.

22. Remove the right-hand (lower) reverse idler

gear support washer, shaft washer and idler gear
from the housing in the same manner as described
in operations 7 to 9 and 19 inclusive for the lefthand idler gear.

20. Remove the upper (right-hand) countershaft

from the housing.
23. Remove the upshift brake from the bottom of
the housing.

21. Remove the bearings from the lower (left-hand)

countershaft in the same manner as described in
operations 13 to 16 inclusive for the upper
countershaft, and remove the countershaft from
the housing.

4/16

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Main Transmission
H. Input Shaft Disassembly

1.
2.
3.
4.
5.
6.
7.

Bearing snap ring

Bearing
Spacer
Gear snap ring
Input gear
Input shaft
Spigot bush

I. Input Shaft Reassembly

Input Shaft Assembly

1. Check the input shaft spigot bush, renew if
necessary..

1. Support the gear, remove the snap ring from the

shaft and push or drive the shaft through the gear
and off the bearing. Remove the spacer.

2. Check the input gear snap ring, renew if

necessary. Install the input shaft into the drive gear
against the snap ring.

4/17

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Main Transmission

3. Place the 3rd/4th gear sliding clutch into the

drive gear against the end of the input shaft and
stand the assembly on the sliding clutch on the
bench. Fit the spacer over the input shaft.

5. Fit the snap ring.

4. Drive the bearing, shrouded face uppermost

onto the shaft using a suitable driver.

6. Paint timing marks on any two adjacent gear

teeth on the input gear. Then paint two gear teeth
exactly opposite the first two.

4/18

5/01

Main Transmission
J. Reverse Idler Gear Disassembly
and Reassembly

1. Circlip
2. Washer
3. Sleeve

4.
5.
6.
7.
8.

Bearing
Reverse idler gear
Idler gear shaft
Support washer
Capscrew

Reverse Idler Gear Assembly

1. Support the gear and press or drive out the

needle roller bearing using a suitable mandrel.
Support the gear and press or drive in the new
bearing until flush with the gear face.

4/19

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Main Transmission
K. Mainshaft Disassembly
Serial Numbers: upto and including N 535711 (ERF), upto and including N 537124 (all other models).

A. Main Section

B. Auxiliary Section

1. Sliding clutch
2. Circlip
3. Graded washer - 3rd gear
4. Spacer
5. Snap ring
6. 3rd speed gear
7. 2nd speed gear
8. Snap ring
9. Spacer
10. Thrust race pack
a Standard washer
b Needle roller thrust race
c Graded washer

11. Main shaft

12. Sliding clutch 1st/2nd speed gear
13. Mainshaft snap ring
14. Graded washer
15. 1st speed gear
16. Plain washer
17. Reverse gear sliding clutch
18. Reverse gear
19. Spacer ring
20. Spring retainer plate
21. Jaw clutch spring - short
22. Jaw clutch

4/20

23. Retaining snap ring

24. Energiser ring
25. Sensor
26. Auxiliary sliding gear centre cluster
27. Shift yoke
28. Jaw clutch spring - long
29. Auxiliary sliding gear - rear
30. Shift yoke
31. Graded thrust washer
32 Thrust washer

5/01

Main Transmission
K. Mainshaft Disassembly
Serial Numbers: upto and including N 535711 (ERF), upto and including N 537124 (all other models).

1. Support the mainshaft assembly in the vice,

forward end downwards and lift off the reverse
gear.

3. Invert the mainshaft in the vice and remove the

3rd speed gear circlip, spacer, washer and 3rd
speed gear.

2. Remove the following in order: Snap ring,

reverse gear sliding clutch, 1st speed (rear) snap
ring and the large internally splined washer.
Remove the 1st speed gear, the externally splined
spacer and the internally aplined graded washer.
Remove the snap ring and the 1st/2nd gear sliding
clutch.

4. Lift off the 2nd speed gear and remove the 2nd
gear stepped spacer. If necessary remove the
internal snap rings from 1st, 2nd, 3rd and reverse
gears.

4/21

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Main Transmission
K. Mainshaft Disassembly
Serial Numbers: N 535712 and above (ERF); N 537125 and above (all other models).

A. Main Section

B. Auxiliary Section

1. Sliding clutch
2. Snap ring
3. Graded washer - 3rd gear
4. Spacer
5. Snap ring
6. 3rd speed gear
7. 2nd speed gear
8. 2nd/3rd gear spacer
9. 2nd gear spacer
10. Thrust race pack
a Standard washer
b Needle roller thrust race
c Graded washer

11. Main shaft

12. Sliding clutch 1st/2nd speed gear
13. Mainshaft snap ring
14. Graded washer
15. 1st speed gear
16. Plain washer
17. Reverse gear sliding clutch
18. Reverse gear
19. Spacer ring
20. Spring retainer plate
21. Jaw clutch spring - short
22. Jaw clutch

4/22

23. Retaining snap ring

24. Energiser ring
25. Sensor
26. Auxiliary sliding gear centre cluster
27. Shift yoke
28. Jaw clutch spring - long
29. Auxiliary sliding gear - rear
30. Shift yoke
31. Graded thrust washer
32. Thrust washer

5/01

Main Transmission
K. Mainshaft Disassembly
Serial Numbers: N 535712 and above (ERF); N 537125 and above (all other models).

1. Support the mainshaft assembly in the vice,

forward end downwards and lift off the reverse
gear.

3. Invert the mainshaft in the vice and remove the

snap ring, graded spacer and 3rd gear assembly.

2. Remove the following in order: Snap ring,

reverse gear sliding clutch, 1st speed (rear) snap
ring and the large internally splined washer.
Remove the 1st speed gear, the externally splined
spacer and the internally splined graded washer.
Remove the snap ring and the 1st/2nd gear sliding
clutch.

4. Using a suitable puller or press remove the 2nd

gear assembly and 2nd/3rd gear mainshaft spacer.

4/23

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Main Transmission
L. Determine and Adjust Mainshaft
End Float

5. The second gear spacer, again using a suitable

puller or press can now be removed from the
mainshaft.

6. If necessary the snap ring and splined spacer

can be removed from the 2nd and 3rd gears.

1. Using a new gasket, position the auxiliary

housing, complete with fully assembled output
shaft, onto the rear of the main housing. Secure
with at least 6 capscrews. Tighten to the correct
torque. Assemble onto the mainshaft front end
spigot one thrust race pack consisting of one
standard thickness steel washer and one vespel
thrust washer, the steel washer against the shaft.
Retain inplace with petroleum jelly.

2. Assemble onto the mainshaft rear spigot a thrust

race pack consisting of one thrust race with one
standard thickness washer and one graded
thickness washer. Alternatively, one graded
thickness steel washer and one vespel thrust
washer may be used. Use the thinnest available
new graded washer. Retain with petroleum jelly.
Position the mainshaft and install the input shaft
and cover using a new gasket. Secure with at least
3 capscrews tighten to the correct torque.

4/24

5/01

Main Transmission

5. Remove the input shaft and mainshaft. If

necessary reassemble with the new size graded
washer rearmost on the rear spigot and recheck
the end float as before. Remove the input shaft,
mainshaft and rear housing. Retain the thrust race
packs in their order for installation later.

3. Position a dial gauge and magnetic base in the

housing with the plunger against the shoulder on
the mainshaft. Push both the input shaft and
mainshaft rearwards and zero the gauge.

4. Hold the input shaft and push the mainshaft

forward and note the end float reading. If the end
float is outside the specified limits, 0,13 - 0,71mm,
a thicker or thinner graded washer must be
selected to replace the existing graded washer on
the rear spigot of the mainshaft.
Washers are available in the following
thicknesses/colour codes.
White
Green
Orange
Purple
Black
Yellow

1,52
1,84
2,16
2,48
2,80
3,12

to
to
to
to
to
to

1,60mm
1,92mm
2,44mm
2,56mm
2,88mm
3,20mm

4/25

5/01

Main Transmission
M. Mainshaft Reassembly (Main
Section)
Serial Numbers upto and including N 535711
(ERF), upto and including N 537124 (all other
models).
Mainshaft Gears - Axial Clearances
The axial clearances for mainshaft gears are:
Reverse/Forward speed gears - 0,13-0,30mm
Graded washers are used to obtain the clearances
within the correct limits; six different thicknesses
are available as follows:
Thickness

Colour Code

6,30 - 6,35mm

White

6,43 - 6,48mm

Green

6,55 - 6,60mm

Orange

6,68 - 6,73mm

Purple

6,80 - 6,86mm

Yellow

6,93 - 6,99mm

Black

2. Support the mainshaft in a soft jawed vice,

forward end uppermost. Place the shouldered
spacer on the mainshaft, shoulder downwards.

Refer to Illustrated Parts List for part numbers.

Note: During reassembly of the mainshaft it is
essential to ensure the correct part numbers are
used in the correct locations. (All major
components have their part number stamped into
them.)

1. If removed, install new snap rings into the 1st,

2nd, 3rd and reverse speed gears.

3. Install the 2nd speed gear over the washer,

clutching teeth downward.

4/26

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Main Transmission

4. Place the 3rd speed gear over the shaft against

the 2nd speed gear, clutching teeth uppermost.

6. Install the graded washer into the 3rd speed

gear, chamfered face uppermost.

5. Install the spacer into the 3rd speed gear.

7. Install the 3rd speed gear reatining circlip.

4/27

5/01

Main Transmission

8. Check the clearance between 2nd and 3rd

gears using two sets of feeler gauges. If the
clearance is not within the correct limits the graded
washer should be removed again and a thicker or
thinner graded washer installed as required in its
place.
10. Install the 1st speed gear snap ring into its
groove in the mainshaft.

9. Invert the shaft and gears in the vice and install

the 1st/2nd gear sliding clutch.

11. Place a graded washer over the shaft,

chamfered face against the snap ring.

4/28

5/01

Main Transmission
M. Mainshaft Reassembly (Main
Section)
Serial Numbers: N 535712 and above (ERF); N
537125 and above (all other models).

Mainshaft Gears - Axial Clearances

The axial clearances for mainshaft gears are:
Reverse/Forward speed gears - 0,13-0,30mm
Graded washers are used to obtain the clearances
within the correct limits; six different thicknesses
are available as follows:
Thickness

Colour Code

6,30 - 6,35mm

White

6,43 - 6,48mm

Green

6,55 - 6,60mm

Orange

6,68 - 6,73mm

Purple

6,80 - 6,86mm

Yellow

6,93 - 6,99mm

Black

2. Check the 2nd and 3rd gear splined spacers for

wear and if still acceptable refit them into the gears
along with new snap rings.

Refer to Illustrated Parts List for part numbers.

Note: During reassembly of the the mainshaft it is
essential to ensure the correct part numbers are
used in the correct locations. (All major
components have their part number stamped into
them.)

3. Press the 2nd gear spacer onto the mainshaft

and then fit the 2nd gear assembly clutching teeth
down.

1. If removed, install new snap rings into the 1st

and reverse speed gears

4/29

5/01

Main Transmission

4. Press the 2nd/3rd gear spacer onto the shaft.

6. Remove the chosen graded mainshaft washer.

5. From the range of graded mainshaft washers

select one which allows the least amount of
clearance between the snap ring and the 2nd/3rd
gear spacer.

7. Fit the 3rd gear assembly clutching teeth up,

selected graded mainshaft washer and snap ring.

4/30

5/01

Main Transmission

8. The 2nd/3rd gear mainshaft clearance should

now be set.

10. Install the 1st speed gear snap ring into its
groove in the mainshaft.

9. Invert the shaft and gears in the vice and install

the 1st/2nd gear sliding clutch.

11. Place a graded washer over the shaft,

chamfered face against the snap ring.

4/31

5/01

Main Transmission

12. Place a spacer over the shaft, flat (mating) face

against the graded washer.

14. Fit the plain washer against the 1st speed gear.

13. Install the 1st speed gear on the shaft and over
the spacer, clutching teeth downwards towards the
sliding clutch.

15. Install the 1st speed gear retaining snap ring.

4/32

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Main Transmission

16. Check the clearance between 1st speed gear

and the washer using two sets of feeler gauges. If
the clearance is not within the correct limits the
graded washer should be removed again and a
thicker or thinner graded washer installed as
required in its place.

17. Install the reverse gear sliding clutch, longer,

clutching teeth uppermost.

18. Install the reverse gear front snap ring into the
groove in the mainshaft.

19. Place the reverse gear graded washer over the

shaft, chamfered face downwards against the snap
ring.

4/33

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Main Transmission

20. Install the spacer, flat (mating) face against the

graded washer.

22. Fit the flat washer against the reverse gear and
the spacer ring against the flat washer.

21. Install the reverse gear over the spacer,

clutching teeth downwards towards the sliding
clutch.

23. Install the reverse gear retaining rear snap

ring.

4/34

5/01

Main Transmission

24. Install the spring retainer plate and the short

jaw clutch spring onto the mainshaft.

26. Check the clearance between the reverse gear

and the flat washer using two sets of feeler
gauges. If the clearance is not within the correct
limits the graded washer must be removed again
and a thicker or thinner graded washer installed as
required in its place. Remove the assembly from
the vice.

25. Locate the jaw clutch on the mainshaft; using

the special tool E113 compress the spring and
install the retaining snap ring.

4/35

5/01

Main Transmission
N. Main Transmission Reassembly

1. Before starting reassembly, make sure the two

magnetic discs are cleaned of swarf and are
securely adhering to the floor of the housing.

3. Install the bearing sleeve into the right-hand

(lower) reverse idler gear/bearing.

2. The gears on the two countershafts are

identical. The lower (left-hand) countershaft has an
extended shaft for a power take off.

4. Position the reverse idler gear, counterbored

face rearmost, into the housing with the washer
located forward of the gear against the support.
Insert the idler gear shaft through the bearing
sleeve and washer into the housing using a little
petroleum jelly to assist retention of the washer.

A. Upper (right-hand) countershaft

B. Lower (left-hand) countershaft

Note: Both gears are identical. When using the

original gears assemble the gears back in the
same position from which they were removed in
order to maintain wear patterns.

4/36

5/01

Main Transmission

5. Drive the shaft into the housing until the circlip

groove is accessible and install the circlip. Pull or
drive the shaft rearward again (gently) until the
circlip abuts the housing.

7. Paint timing marks on the drive gear and on the

two countershafts. On the drive gear, if not already
marked, paint any two adjacent teeth. Then paint
the two teeth directly opposite the first two.

6. Rotate the shaft to align the slot with the oil hole
in the housing. Apply sealer to the capscrew
threads and install the support washer. Do not
overtighten.

8. On each countershaft, the front (drive) gear is

marked on its rear race with an 'O' by one of the
teeth. Paint this tooth on each gear. Illustration
shows the three gears (disassembled) correctly
marked.

4/37

5/01

Main Transmission

9. Locate the lower (left-hand) countershaft

(extended shaft) into the housing centralising it in
the bearing bores.

11. Using a suitable flanged installer drive the

bearing onto the shaft and into the housing. Fit the
retaining snap ring on the shaft.

10. Locate the countershaft rear bearing over the

shaft and into the housing.

12. Locate the countershaft front bearing on the

shaft, snap ring groove outermost and using a
suitable flanged installer, drive the bearing onto the
shaft and into the housing.

Note: The inner track of the bearing is radiused on

one face and chamfered on the other. The
radiused face must be toward the front, chamfer to
the rear.

4/38

5/01

Main Transmission

13. Install the bearing retaining snap ring on the

shaft. Rotate the shaft to bring the timing mark in
line with the mainshaft bores.

15. Place the upper (left-hand) reverse idler gear

into position, counterbored face to the rear, resting
it in mesh with the countershaft and against the left
side of the case.

14. Place the upper (right-hand) countershaft in the

housing. Use wooden blocks in the bearing bores
to support the countershaft as far to the right-hand
side as possible and align the timing marks to face
the lower countershaft.

16. Place the assembled mainshaft into the

housing (rear end first).

4/39

5/01

Main Transmission

17. Locate the mainshaft approximately in position

and in mesh with the lower countershaft and
support at the rear on a suitable wood block.

19. Place the 3rd/4th gear sliding clutch into the

end of the assembled input shaft. Align the timing
marks on the input shaft with the lower (left-hand)
countershaft and install the input shaft, taking care
not to dislodge the thrust race pack.
Note: Note the different sizes of clutching teeth on
Serial Numbers N 535712 and above (ERF), N
537125 and above (all other models).

18. Place the mainshaft front thrust race pack onto

the mainshaft front spigot, steel washer against the
shaft. Retain in place with petroleum jelly.

20. Push the input shaft fully home and install the
input shaft cover. Note the correct position of the
drilled capscrews, when fitted. Tighten to the
correct torque. Insert two wedges between reverse
gear and the housing to prevent the mainshaft
sliding rearwards.
Check to ensure that the countershaft is still
correctly timed to the input shaft.

4/40

5/01

Main Transmission

21. Rotate the upper (right-hand) countershaft as

necessary to align the timing marks with the input
shaft, engage the gear teeth and support the
countershaft in position with a dummy support tool.

23. Remove the dummy support from the rear of

the upper (right-hand) countershaft and install the
rear bearing as described in sub-operations 10 and
11 ensuring that the radiused face of the inner
track is toward the front, chamfer to the rear. Fit
the snap ring.

22. Partially install the countershaft front bearing

and check the timing marks are aligned correctly.
Using a suitable flanged installer drive the
countershaft front bearing onto the shaft and into
the housing. Fit the snap ring.

24. Raise the rear of the mainshaft slightly and roll

the upper reverse idler gear into mesh with the
reverse gear. Grease one side of the thrust washer
and insert it between the front face of the gear and
the housing. Insert the idler gear shaft into the
housing.

4/41

5/01

Main Transmission

Main Transmission
O. Reassembly of Auxiliary Section

25. Drive the shaft into the housing until the circlip
groove is accessible and install the circlip. Align
the slot in the shaft with the oil hole in the housing,
apply sealer to the capscrew threads and install
the support washer.

1. Paint timing marks on both auxiliary

countershafts. Paint along all three gear teeth on
each countershaft in line with the 'O' stamped on
the front gear..

26. Install the upper and lower auxiliary

countershaft front beaings, driving them into the
housing bores using a suitable flanged driver, until
they abut the two reverse idler gear support
washers.

2. On the forward sliding gear paint any two

adjacent teeth and then two teeth directly opposite
the first two. Paint highlighting marks on the sensor
ring blocker teeth to aid alignment with the jaw
clutches during assembly.

4/42

5/01

Main Transmission

3. Paint highlighting marks on the two teeth, one

each side of the master blocking spline on the jaw
clutches, to aid alignment with the sensor ring
during assembly.

5. Locate the jaw clutch on the mainshaft with the

marked master spline uppermost. Using the
special tool, compress the spring and install the
front jaw clutch retaining snap ring on the
mainshaft.

4. Remove the support block and install the spring

retainer plate and the short jaw clutch spring on
the mainshaft.

6. Install the centre jaw clutch snap ring on the

mainshaft. Install the upper (left-hand) auxiliary
countershaft into its front bearing. Align the timing
marks toward the mainshaft.

4/43

5/01

Main Transmission

7. Place a 20 mm dia x 300 mm long bar in the

housing with the end located in the housing web.
Chamfer the end of the bar if necessary.

9. Install the sliding gear cluster onto the mainshaft

ensuring that:
a: blocker spline on front sensor is aligned with jaw
clutch.
b: timing mark on front sliding gear is correctly
meshed with upper (left-hand) countershaft timing
mark.

8. Lay the lower (right-hand) auxiliary countershaft

on to the bar and against the side of the housing.
Align the timing marks towards the mainshaft.

10. Install the jaw clutch for the rearmost gear of

the cluster into the sensor and against the snap
ring on the mainshaft.

4/44

5/01

Main Transmission

11. Place the longer jaw clutch spring on the

mainshaft, place the rear jaw clutch against the
spring. Using the special tool compress the spring
and install the rear snap ring onto the mainshaft.

13. Install the sliding gear cluster yoke into the

cluster, offset boss towards the front.

12. Remove the bar supporting the lower (righthand) auxiliary countershaft, align the timing marks
and install the countershaft into its front bearing.
Check to ensure the gears are correctly timed.

14. Install the mainshaft rear thrust race pack (one

standard washer, one thrust race and one graded
washer OR one graded washer and one vespel
thrust washer) onto the mainshaft rear spigot.
Retain in place with petroleum jelly.

4/45

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Main Transmission

15. Install the gasket. Raise the auxiliary rear

housing using the lifting bracket and a hoist.

18. Fit the remaining capscrews and tighten to the

correct torque. Note the correct positions of the
two longer capscrews.

16. Install the auxiliary housing to the main

housing ensuring that:
a. Timing marks align and engage
b. Jaw clutch aligns and engages
c. Yoke boss aligns with the piston operating bar
Remove the lifting bracket, push the housing fully
home and temporarily secure with two capscrews.

17. Carry out the following checks before

proceeding any further.
a. Engage one of the sliding clutches in the main
section and rotate the input shaft several times.
The main gear train should rotate without binding.
b. Rotate the output shaft flange. The auxiliary
gear train should rotate without binding.
c. Engage the sliding gear cluster on to one of the
jaw clutches and again rotate the input shaft. The
entire drive train through to the output shaft flange
should rotate without binding.
d. If there is any binding either a jaw clutch is not
aligned or the auxiliary gear train is not correctly
timed.

19. Align the sliding gear yoke with the splitter

cylinder bar and install the lockscrew. Tighten to
the correct torque and lockwire to secure.

4/46

5/01

Main Transmission

20. Using a suitable flanged driver drive the

bearing into the housing. Similarly fit and install the
upper auxiliary countershaft rear bearing.

22. Tighten the flange nut to correct torque. Stake

the nut into the groove on the shaft.

21. Fit bearing outer spacers and the snaprings.

23. Install the bearing covers using new gaskets.

Tighten the capscrews to the correct torque.

4/47

5/01

Main Transmission

24. Install the pressure regulating valve and the air

lines. Check the operation of the air system using
a dry, regulated air supply and ensure freedom
from leaks.

26. Fit the shift bar housing capscrews and tighten

to the correct torque. Note the position of the lifting
eyes together with the longer bolts.

25. Ensure that all the sliding clutches and the shift
bar housing yokes are in neutral and install the
shift bar housing, using a new gasket.

27. Install the remote control housing and gasket.

Note the conical nuts, tighten to the correct torque,
then fit and tighten the lock nuts.

4/48

5/01

Main Transmission

28. Raise the transmission from the stand and

install the upshift brake using a new gasket. Fit the
capscrews and tighten to the correct torque. Check
backlash as described. Connect the air line to the
pulse unit.

4/49

5/01

Section 5

Changing the Input Shaft

5/01

Changing the Input Shaft

In some cases in service it may be necessary to

renew or replace the input shaft due either to wear
on the splines caused by the clutch or for reasons
of implementing a change in clutch type or clutch
hub diameter.
In these instances the input shaft can be renewed
without disassembling the transmission other than
the removal of the clutch housing and shift bar
housing, by carrying out the following detailed
procedure:

2. Remove the front bearing cover.

Note: There are two types of cover fitted
depending on whether a push or pull action clutch
release bearing is installed, Note the position of
the two special capscrews when a push action
clutch is fitted.

Input Shaft Disassembly

1. Remove the gear shift remote control housing

and shift bar housing from the transmission.t.

3. Grasp the input shaft firmly and joggle the shaft,

gear and bearing out of the housing. Retain the
parts in order for reassembly.

5/1

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Changing the Input Shaft

Input Shaft Reassembly

4. Remove the mainshaft thrust washers and the

3rd/4th gear sliding clutch from the mainshaft..

Input Shaft - Exploded View

5. Support the gear, remove the bearing snap ring

and press or drive the shaft through the gear and
off the bearing. Remove the spacer from the gear.

1. Check the input gear snap ring, renew if

necessary.

1.
2.
3.
4.

5/2

Bearing snap ring

Bearing assembly
Spacer
Gear snap ring

5. Input gear
6. Input shaft
7. Spigot bush

5/01

Changing the Input Shaft

2. Secure the input shaft in a vice and install the

spigot bush using a suitable driver.

4. Install the sliding clutch into the drive gear and

stand the asembly on the bench on the sliding
clutch. Fit the spacer over the input shaft.

3. Assemble the new input shaft into the drive gear

against the snap ring.

5. Drive the bearing, shrouded face upward, onto

the shaft using a suitable driver.

5/3

5/01

Changing the Input Shaft

6. Fit the snap ring.

Note: The ends of the snap ring are angled slighty
to ease removal. Ensure snap ring is correctly
fitted.

7. Locate the timing marks on the two countershaft

input drive gears (marked O) and paint the tooth at
both ends and along its length.

8. Paint timing marks on any two adjacent gear

teeth on the drive gear and the two teeth exactly
opposite the first two.

9. Place the mainshaft thrust race pack onto the

mainshaft spigot, steel thrust washer against the
shaft. Retain in place with petroleum jelly.

5/4

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Changing the Input Shaft

10. Install the 3rd/4th sliding clutch into the input

shaft, align the timing marks and gently push the
input shaft and bearing into the transmission
housing. Lift the mainshaft slightly to aid
installation, Do not drift the shaft in or the thrust
race pack may be dislodged or damaged.

12. Install the front bearing cover. When a push

type clutch release is fitted the two capscrews with
the drilled heads are fitted into the uppermost two
holes. Tighten the capscrews to the correct torque.

11. Ensure the timing marks are still aligned.

13. Reinstall the shift bar housing and remote

control housing.

5/5

5/01

Section 6

Upshift Brake

5/01

5/01

Upshift Brake
Serial Numbers upto and including N 533586.

Upshift Brake - Exploded View

1. Capscrew
2. Tab washer
3. Keep plate
4. Spacer
5. Bearing

6. Spacer
7. Gear
8. Friction disc outer (3 off)
9. Friction disc inner (4 off)
10. Hub shaft

11. Compression spring

12. Pressure plate
13. Piston
14. O-ring
15. Piston support shaft

16.
17.
18.
19.

O-ring
O-ring
Gasket
Housing

Upshift Brake - Sectional View

6/1

5/01

Upshift Brake
Upshift Brake Removal and
Disassembly

1. Disconnect the air hose from the upshift brake,

drain the transmission oil and remove the upshift
brake.

3. Straighten the tab washer. Remove the keep

plate retaining screw and keep plate. Support the
pressure plate and piston assembly.

2. Mount the assembly in a soft jawed vice and

remove the elbow connector. Remove the two
countersunk head retaining screws. Remove the
piston support shaft.

4. Remove the piston return spring.

6/2

5/01

Upshift Brake

5. Remove the pressure plate and piston

assembly.

8. Remove the spacer rings and hub from the gear

and if the bearing is to be renewed, drive the
bearing out of the gear.

6. Lift out the gear, hub and brake disc assembly.

9. Separate the piston from the pressure plate.
Reassembly and Installation

7. Remove the lined and unlined brake discs from

the splined hub and gear.

6/3

5/01

Upshift Brake
Reassembly and Installation

1. Clean and examine all parts, renew as

necessary. Renew all O rings. Use silicone
lubricant when assembling the O rings. If removed
install a new bearing with shield towards brake
plate into the gear using a suitable flanged driver.

3. Install the thinner spacer ring over the hub and

install the hub and gear into the housing.

2. Install the hub into the gear bearing, tapping the

hub lightly with a soft faced hammer if necessary,
until fully home.

4. Install the four lined and three unlined brake

discs over the hub and into the gear in alternate
sequence.
Note: The first and last plates will be lined plates
when correctly installed.
Note: SAMT transmissions only have three lined
and two unlined plates.

6/4

5/01

Upshift Brake

5. Ensure that the lined plates slide easily over the

splines on the hub and the unlined plates in the
slots in the gear.

7. Install the piston and pressure plate assembly,

pressure plate against the top, lined, plate.

6. Install the spacer inside the gear.

8. Refit the piston support shaft and secure with

two new patch locked countersunk headed screws.
Tighten to the correct torque.
Note: Loctite sealer may be used where new
screws are not available.

6/5

5/01

Upshift Brake

9. Install the piston return spring and keep plate.

Fit a new patch lock capscrew, tab washer and
tighten to the correct torque. Ensure the assembly
rotates freely.
Note: Loctite sealer may be used where a new
patchlock capscrew is not available.

10. Using PTFE tape or suitable sealer, install the

air connection elbow to the upshift brake. Install
the upshift brake assembly to the transmission
housing using a new gasket. Tighten the
capscrews to the correct torque. Reconnect the air
feed from the pulse unit.

11. Check the backlash through the hole in the

bottom of the housing. The correct backlash is
0,15 to 0,45 mm . Fit a thicker or a thinner gasket
to increase of decrease the backlash if necessary.

6/6

5/01

Upshift Brake
Serial Numbers N 533587 and above.

Upshift Brake - Exploded View

1.
2.
3.
4.
5.
6.

Housing
Splined shaft
Gear
Bearing
Spacer
Bolt

13.
14.
15.
16.
17.
18.

7. Friction disc - inner

8. Friction disc - outer
9. O-ring
10. Spring
11. Pressure plate
12. Piston

O-ring
O-ring
Shaft
O-ring
Bolt
Washer

19.
20.
21.
22.
23.

O-ring
Drain plug
Washer
Gasket
Elbow

Upshift Brake - Sectional View

6/7

5/01

Upshift Brake
Removal and Disassembly

1. Disconnect the air hose from the upshift brake,

drain the transmission oil and remove the upshift
brake.

3. Remove the bolt (note the washer and O-ring).

Remove the piston support shaft.

2. Mount the assembly in a soft jawed vice and

remove the elbow connector.

4. Remove the pressure plate and piston

assembly. Remove the spring.

6/8

5/01

Upshift Brake

5. Remove the four bolts securing the splined shaft

and lift out the gear, splined shaft and brake disc
assembly from the housing.

7. Remove the spacer ring and shaft from the gear

and if the bearing is to be renewed, drive the
bearing out of the gear.

6. Remove the lined and unlined brake discs from

the splined shaft and gear.

8. Separate the piston from the pressure plate.

6/9

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Upshift Brake
Reassembly and Installation

1. Clean and examine all parts, renew as

necessary. Renew all O-rings. If removed install a
new bearing into the gear using a suitable flanged
driver.

3. Install the spacer ring over the shaft and install

the shaft and gear into the housing. Install the four
bolts and tighten to the correct torque (40 - 50
Nm).

2. Install the shaft into the gear bearing, tapping

the shaft lightly with a soft faced hammer if
necessary, until fully home.

4. Install the four lined and three unlined brake

discs over the shaft into the gear in alternate
sequence.
Note: The first and last plates will be lined plates
when correctly installed.

6/10

5/01

Upshift Brake

7. Refit the piston support shaft and secure with

the appropriate bolt (not forgetting the O-ring and
washer). Tighten to the correct torque (46 - 60
Nm).
5. Ensure that the lined plates slide easily over the
splines on the shaft and the unlined plates in the
slots in the gear.

8. Using PTFE tape or suitable sealer, install the

air connection elbow to the upshift brake. Install
the upshift brake assembly to the transmission
housing using a new gasket. Tighten the socket
headed countersunk screws to the correct torque.
Reconnect the air feed from the pulse unit.

6. Install the O-ring, spring and pressure plate

assembly, pressure plate against the top lined
plate.

9. Check the backlash through the hole in the

bottom of the housing. The correct backlash is
0.15 to 0.45 mm. If there is insufficient backlash
use multiple gaskets to obtain the correct amount.
Refit the drain plug and washer. Tighten to the
correct torque (41 - 47 Nm).

6/11

5/01

5/01

Section 7

PTO Installation

5/01

5/01

PTO Installation
Fitting Extended Countershaft

Countershaft Extension Assembly

1. Snap ring.
2. Adaptor coupling.
3. PTO extension shaft.
4. Bearing.
5. Adaptor ring.
6. Spacing sleeve.
7. Cover.

1. Remove left-hand coverplate (7 bolts).

7/1

5/01

PTO Installation
Assembly of Extended Countershaft

1. Insert the snap ring into the adaptor coupling.

3. Fit the bearing on to the shaft with the radius of

the inner bearing ring to the shaft collar.

2. Fit the adaptor coupling onto the rear of the lefthand countershaft.

4. Fit the spacer sleeve.

7/2

5/01

PTO Installation

5. Insert the shaft assembly into the adaptor

coupling. Use a suitable soft drift against the
bearing outer ring to drive it into the housing.

7. Fit the cover. Tighten the three capscrews to the

correct torque.
Additional screws as required supplied with PTO
kit.
Refer to PTO Fitting Instructions to fit PTO.

6. Fit the adaptor ring onto the bearing.

7/3

5/01