WILLYS MODEL “MB" }-TON 4 x 4 GOVERNMENT TRUCK TRANSMISSION The transmission, Fig. 1 is‘ of the three speed, synchromesh type with synchronized 2nd and high speed gears. See shifting diagram, Fig. 4 in Driver's Instructions Section. The transmission is bolted to the rear face of the flywheel bell housing with four cap screws and is supported on a rubber insulator at the center frame cross member which is the rear engine support or mounting. Removal of Transmission and Transfer Case from Engine 1. Remove front and rear propeller shafts at universal joint in accordance with instructions under the "Propeller Shafts and Universal Joints”. 2. Disconnect speedometer cable at transfer case. FIG, 1—TRANSMI: TON0700-74 WILLYS MODEL "MB" J¢-TON 4 x 4 GOVERNMENT TRUCK 9. 10. iL. 12, 13. 14, 15. 16. Disconnect brake and engine snubbing cables. Remove nuts holding rear mounting to frame cross member. Remove transfer case snubbing rubber bolt nut at cross member. Remove transmission shift lever by unscrewing er collar at top of shift housing. Disconnect the clutch release cable at bell crank and remove; also, remove clutch release lever No. 10, Fig. 2, "‘Clutch Section” through the inspection hole in the flywheel bell housing. Place jacks under engine and transmission. Remove floor board inspection plate, drain radiator and remove upper hose. Remove transfer shift lever pivot pin screw and lubricator. Remove shift lever pin and remove levers. Remove bolts holding center cross member to frame side rail and remove cross member. Remove bolts holding transmission to flywheel bell housing. Force transmission to right and disconnect clutch control lever tube ball joint. Lower jacks under engine and transmission; slide transmission assembly towards rear of vehicle until clutch shaft clears bell housing. Lower jack under transmission and remove assembly from under chassis. FIG, 2—-REMOVING BEARING SNAP RING Disassembly of Transmission Drain lubricants from both the transmission and transfer case through drain plug holes in bottom of each case. It is advisable to clean the outside of the cases thoroughly with water or other suit- able cleaning fluid before attempting to disassemble the units. To disassemble the unit the following procedure is recommended: 1. Remove cap screws and lock washers holding rear cover. No. 37, Fig. 3 in Transfer Case Section. 2. Remove cotter pin, nut and washer permitting removal of main shaft gear No. 57 FIG. 3-REMOVING SNAP RING 3. Remove the four cap screws holding control housing to top of transmission and remove housing. 4. Remove shifter plate spring and take off shifter plate, No. 11, Fig. 4. 5. Loop a piece of wire around main shaft, just rear of main shaft second speed gear, twist wire and attach one end to the right hand front cover screw and the other end to the left hand cover screw, drawing the wire tightly to prevent the main shaft from sliding out of the case when transfer case is removed. G. Remove the five cap screws holding the transfer case to the rear face of the transmission.WILLYS MODEL “MB” }{-TON 4 x 4 GOVERNMENT TRUCK 0700-75 | ' 7, Support transfer case and with a rawhide mallet or brass rod and hammer, tap lightly on end of shaft and at the same time draw the transfer case away from the transmission. Be careful not to lose transmission gear shift interlock plunger. The transmission main shaft rear bearing No. 34, Fig. 4 should slide out of transfer case and remain in transmission. 8, Remove three screws holding main drive gear bearing retainer, No. 1 and remove retainer and gasket. . Remove shift fork guide pin, No. 20 through front of tranamission. 10. Remove shift fork set screws with special wrench furnished in tool kit and remove shift shafts and fotks. Be careful not to lose poppet springs and balls. ‘11, Remove lock plate at rear of transmission holding countershaft and reverse idler gear shaft. 12.. With a drift, drive out the countershaft. 13. Remove main drive gear bearing, shaft and synchronizer blocking ring. 14, Remove snap rings from main drive gear shaft and bearing, Fig. 2 and 3 and remove bearing from shaft. 15. Remove main shaft assembly. 16, Remove countershaft gear set and three thrust washers, two bushings and a spacer. 17. Remove reverse idler gear shaft and gear. To remove the gears on main shaft, first remove snap ring No. 27, Fig. 4, on end of shaft holding transmission high and intermediate clutch hub, No. 28. After the removal of the snap ring, the gears will slide off the shaft without difficulty. To disassemble synchronizer unit, push apart. Wash all parts in suitable cleaning Muid and in- spect for wear and damaged parts, replacing any parts which show excessive wear or damage. Assembly of Transmission The assembly of the parts in the transmission should be performed in the reverse manner in which it was dismantled making reference to exploded views of parts as shown in Fig. 4, for sequence of assembly. When assembling synchronizer unit assembly place the right end of a synchronizer spring No. 14 in one shifting plate, Turn the unit around and make exactly the same installation with the other spring in the same shifting plate. This will actually place the spring action opposed to each other. _. The bushings in countershaft gear set are of the floating type, being free to turn within the gear as well as on the shaft. When making assembly of countershaft to transmission case, dip these bush- ings in lubricant of S.A.E. 90 grade and be sure the spacer is installed between the two bushings. The steel thrust washer, No. 43 at the rear of coun- tershaft gear is pinned in the case and the bronze washer, No. 42 is installed between steel washer and gear. Only one bronze washer, No. 37 is used at the front. ‘The main shaft balJl bearing, No. 4 is assembled to shaft so that the sealed side is in transmission, open side to transfer case. TRANSMISSION TROUBLE AND REMEDIES . SYMPTOMS Slips Out of High Gear Transmission misaligned with Bell Housing..... End play in Main Drive Gear. ...........005. Damaged Pilot Bearing or Front Bearing... ... Bent Shifting Fork, .............0 0c cee uues Slips Out of Second Bent Shifting Fork.............0.0. cece eeeee Worn Gear... 6. cc ccc cee ee eee eee enue Weak Poppet Spring..................000005 Noise in Low Gear Rear Bali Bearing Broken...............00685 Gear Teeth Pitted or Worn,.................. Shiftimg Fork Bent.............0..0.c0cceeee Lack of Lubrication.............0... 00. .000 ee Grease Leak into Bell Housing Gasket Broken Front Bearing Retainer........ Transmission Case Overfilled with Lubricant... PROBABLE REMEDY (age Transmission Case to Belt ‘(Housing and Bell Housing to Engine Tighten Front Retainer Replace Replace Replace Replace Replace. Replace Replace gears Replace Drain and Refill Replace Drain off to proper levelMONUL LNAWNUIAOD F * ¥ NOL-% «AN. THACOW SATIN \ 44 45 46 47 48 FIG. 4-TRANSMISSIONz COW ao mow PM Willys Part No. 640017 635844 635846 636885 A-5554 639422 637495 A-1148 635837 | 635838 635841 635839 © 637834 637831 637833 636196 636200 A-1155 A-1156 635836 636200 636197 636879 635844 A-7.38 A-410 637835 637830 637832 637831 637834 638798 A-819 A-916 635868 52510 635812 A-739 638948 A-878 638949 635811 A-879 635861 A-1380 635868 52045 635857 392328 635863 A-1379 5140 5140 A-880 636882 638952 640018 WILLYS MODEL “MB” 4-TON 4 x 4 GOVERNMENT TRUCK 9700-77 FIG. 4—TRANSMISSION (EXPLODED) ' Ford Part No. GPW-7050 GPW-7064 B-7070 GPW-7025 GPW-7017 GPW-7120 GPW-7051-B GPW-7005 GPW-7234 353081-S7 GPW-7216 GPW-7208 GPW-7107 GPW-7109 GPW-7106 GPW-7230 GPW-7245 GPW-7241 GPW-7240 GPW-7206 GPW-7245 GPW-7231 GPW-7100 GPW-7064 GPW-7062 GPW-7080 GPW-7059 GPW-7105 GPW-7116 GPW-7109 GPW-7107 GPW-7102 GPW-7061 GP-7065 20366-S - 34941-S GPW-7119 GPW-7113 GPW-7111 GPW-7121 GPW-7135 GPW-7129 GPW-7126 GPW-7223 GPW-7210 — 20366-5 34806-S GPW-7204 GPW-7227 BB-7228 BB-7220 359064-5 353064-5 GPW-7115 GPW-7142 GPW-7140 GPW-7052 Name Transmission Main Drive Gear Bearing Retainer Transmission Main Drive Gear Snap Ring Transmission Main Drive Gear Bearing Snap Ring Transmission Main Drive Gear Bearing Transmission Main Drive Gear Transmission Main Shaft Pilot Roller Bearing Transmission Main Drive Gear Bearing Retainer Gasket Transmission Case Transmission Poppet Spring Transmission Shift Rail Poppet Ball Transmission Shift Plate Transmission Shift Plate Spring ‘Transmission Synchronizer Blocking Ring Transmission Synchronizer Spring Transmission Second and Direct Speed Clutch Sleeve Transmission Shift Fork—High and Intermediate Transmission Shift Fork Lock Screw Transmission Shift Rail—High and Intermediate Transmission Shift Rail—Low and Reverse Transmission Shift Fork Guide Pin Transmission Shift Fork Lock Screw Transmission Shift Fork Low and Reverse Transmission Sliding Gear—Low and Reverse Transmission Main Shaft Snap Ring Transmission Main Shaft Bearing Spacer Transmission Oil Retaining Washer Transmission High and Intermediate Clutch Hub Snap Ring Transmission High and Intermediate Clutch Hub Transmission Synchronizer Shifting Plate Transmission Synchronizer Spring Transmission Synchronizer Blocking Ring Transmission Main Shaft Second Speed Gear Assembly Transmission Main Shaft Transmission Main Shaft Bearing Hex. Head Screw (Bearing Retainer) Lockwasher Transmission Countershaft Thrust Washer—Front Transmission Countershaft Gears Transmission Countershaft Transmission Countershaft Gear Bushing Transmission Countershaft and Idler Lock Plate Transmission Countershaft Thrust Washer—Rear (Bronze) Transmission Countershaft Thrust Washer—Rear (Steel) Transmission Control Housing Gasket Transmission Control Lever Assembly (Gear Shift Lever) Hex. Head Screw (Control Housing) Lockwasher Transmission Control Housing Assembly - Transmission Control Lever Support Spring Transmission Control Housing Cap Washer Transmission Control Housing Cap Transmission Drain Plug Transmission Filler Plug Transmission Countershaft Bearing Spacer Transmission Reverse Idler Gear Assembly Transmission Reverse Idler Gear Shaft Front Bearing Retainer Oil Seal0700-78 WILLYS MODEL “MB” \4-TON 4 x 4 GOVERNMENT TRUCK TRANSMISSION SPECIFICATIONS Transmission Mounting Shift Lever Location Type..... Ce ee a hh T 84J . Synchronous Mesh Unit Power Plant On Transmission Speeds... 00. eee ee eee 3 Forward—1 Reverse Ratio LOW, fo ee ee nae 2.665 Second 1,564 High... 2.0... et ee 1:1 Reverse... 000 ce ee ee ees 3.554 Bearings Clutch Shaft (Flywheel). .................... Bushing Clutch Release.,........00 0.0.0.0 0. c eee cee Ball Clutch Shaft Rear (Main Drive Gear)......... Ball Main Shaft Front.......................000- 13 Rollers Main Shaft Rear......... 0.0.00. c ce cee eee Ball Counter Shaft Gear. ..... 00.0... 0 eee Bushings (2) Reverse Idler Gear... 2.0.2.0. 0 00 eee ne Bushing Transmission Oil Capacity—(Pts.). 000.000 cece eee See Capacity Chart, Page 3 S.A.E. Viscosity i See Lubrication Chart, Page 12