Main Shaft Assembly For Single-Range
Main Shaft Assembly for Single-RangeREMOVAL
1) Remove the manual transmission assembly from the vehicle.
2) Remove the transfer case together with the extension case assembly.
3) Remove the transmission case.
4) Remove the drive pinion shaft assembly.
5) Remove the main shaft assembly.
INSTALLATION
1) Attach the needle bearing and oil seal to the main shaft assembly.
NOTE:
^ Wrap the clutch splined section with vinyl tape to prevent damage to the oil seal.
^ Apply NICHIMOLY N-130 (or equivalent) to the sealing lip of the oil seal.
^ Use a new oil seal.
2) Fit the knock pin hole of the needle bearing outer race to the transmission case knock pin, and install the main shaft assembly.
NOTE:
^ Align the end face of the seal with surface (A) when installing the oil seal.
^ Face the cutout portion of the snap ring for the ball bearing to the drive pinion shaft assembly.
3) Install the drive pinion shaft assembly.
4) Check each shifter fork. Shifter Fork and Rod
5) Select a main shaft rear plate.
6) Install the transmission case.
7) Install the transfer case together with the extension case assembly.
8) Install the manual transmission assembly to the vehicle.
DISASSEMBLY
1) Put vinyl tape around main shaft spline to protect the oil seal from damage. Then pull out the oil seal and needle bearing by hand.
2) Remove the lock nut and lock washer from the main shaft assembly.
NOTE:
Flatten the lock nut tab before removing the lock nut.
ST1 498937000 TRANSMISSION HOLDER
ST2 499987003 SOCKET WRENCH (35)
3) Remove the 5th hub & sleeve No. 2, baulk lever, baulk ring, and 5th drive gear & needle bearing.
4) Using ST1 and ST2, remove the rest of the parts.
NOTE:
^ When replacing the sleeve & hub, replace them as a set.
^ Do not disassemble the sleeve & hub; the engaging point is pre-determined.
^ If it is necessary to disassemble, mark the engaging points on the splines beforehand.
ST1 899864100 REMOVER
ST2 899714110 REMOVER
ASSEMBLY
1) When the sleeve & hub assemblies have been disassembled, reassemble by aligning the alignment marks.
NOTE:
Position the open ends of the spring 120° apart.
2) Install the 3rd drive gear, outer baulk ring, synchro cone, inner baulk ring, 3rd needle bearing and sleeve & hub assembly on the main shaft.
NOTE:
Align the groove in baulk ring with the shifting insert
3) Install the 4th needle bearing race onto the main shaft using ST1, ST2 and press.
CAUTION:
Do not apply a load in excess of 10 kN (1 ton, 1.1 US ton, 1.0 Imp ton).
ST1 899714110 REMOVER
ST2 499877000 RACE 4-5 INSTALLER
4) Install the baulk ring, needle bearing, 4th drive gear and 4th gear thrust washer to the main shaft.
NOTE:
^ Align the baulk ring and hub & sleeve assembly with the key groove.
^ Make sure the thrust washer is facing the correct direction.
5) Press-fit the double ball bearing into the rear section of the main shaft using ST1, ST2 and a press.
CAUTION:
Do not apply a load in excess of 10 kN (1 ton, 1.1 US ton, 1.0 Imp ton).
NOTE:
^ Install the snap ring side of the double ball bearing facing the 5th drive gear side.
^ Use a new double ball bearing.
ST1 899714110 REMOVER
ST2 499877000 RACE 4-5 INSTALLER
6) Using the ST1 and ST2, install the 5th gear thrust washer and 5th needle bearing race onto the rear section of the main shaft.
CAUTION:
Do not apply a load in excess of 10 kN (1 ton, 1.1 US ton, 1.0 Imp ton).
NOTE:
Make sure the thrust washer is facing the correct direction.
ST1 899714110 REMOVER
ST2 499877000 RACE 4-5 INSTALLER
7) Install the rest of the parts to the rear section of the main shaft.
CAUTION:
^ Install the baulk lever so that the concave side faces toward the 5th hub.
^ Align the protruded section of baulk ring between the baulk levers.
8) Tighten the lock nuts to the specified torque using ST1 and ST2.
NOTE:
^ Use new lock nuts and lock washers.
^ Make sure the lock washer is installed in the proper direction.
ST1 499987003 SOCKET WRENCH (35)
ST2 498937000 TRANSMISSION HOLDER
Tightening torque:
120 Nm (12.2 kgf-m, 88.5 ft-lb)
9) Crimp lock nuts in two locations after tightening.
CAUTION:
When crimping the lock nut, be careful not to crack it.
INSPECTION
Disassembled parts should be washed with cleaning solvent first, then inspected carefully.
1) Bearing
Replace the bearings in the following cases.
^ When the bearing balls, outer races and inner races are broken or rusty.
^ When the bearing is worn.
^ When the bearings fail to turn smoothly or emit noise in rotation after gear oil lubrication.
^ When bearing has other defects.
2) Bushing (each gear)
Replace the bushing in following cases.
^ When the sliding surface is damaged or abnormally worn.
^ When the inner wall is abnormally worn.
3) Gear
Replace gears in the following cases.
^ Replace the gear with new part if its tooth surfaces are broken, damaged or excessively worn.
^ Correct or replace if the contact surface between the cone and baulk ring is rough or damaged.
^ Correct or replace if the inner surface or end face is damaged.
4) Baulk ring, synchro cone
Replace the baulk ring and synchro cone in the following cases.
^ When the inner surface and end face are damaged.
^ When the baulk ring inner surface is abnormally or partially worn down.
^ When the contact surface of the baulk ring insert section is cracked or abnormally worn.
^ If the gap between the end faces of the baulk ring and the gear splined part is excessively small, check the clearance (A) while pressing the ring against the cone.
Clearance (A):
0.5 mm (0.020 in) or more
^ Apply gear oil to the cone of the gear and while press-fitting the baulk ring, check there is no rotation in the circumferential direction.
5) Shifting insert key
Replace the insert key if deformed, excessively worn or defective in any way.
6) Coupling sleeve and synchronizer hub
^ Check the slipping condition of the coupling sleeve.
^ Check the splines on the coupling sleeve and synchronizer hub for wear.
7) Oil seal
Replace the oil seal if the lip is deformed, hardened, worn or defective in any way.
8) Gearshift mechanism
Repair or replace the gearshift mechanism if excessively worn, bent or defective in any way.
ADJUSTMENT
Selection of main shaft rear plate:
Measure the protrusion amount (A) of ball bearing from transmission main case surface, and select a suitable plate in the following table.
NOTE:
Before measuring, tap the end of main shaft with a plastic hammer lightly in order to make the clearance zero between the main case surface and moving flange of bearing.
