Mainshaft
Mainshaft
Mainshaft Components - Disassembled View
Disassembly
1. Rotate the mainshaft. Position the mainshaft in the Gear Pack Fixture with the input shaft pointing upward.
2. NOTE: Installing a new input shaft will affect mainshaft clearance. Carry out a mainshaft clearance measurement. For additional information, refer to the Transmission Assembly procedures.
Remove the input shaft.
3. Using the Shaft Protector Set, 2 or 3 Jaw Puller and the Bearing Puller, remove and discard the input shaft bearing.
4. Remove and discard the input shaft rear oil dam.
5. Inspect the input shaft and input shaft bearing for damage or wear. For additional information, refer to Manual Transmission/Transaxle &/or Clutch, M/T.
- Inspect the input shaft splines for wear and damage. Install a new shaft as necessary.
6. NOTICE: To prevent damage, do not heat the bearing higher than 150°C (302°F).
A new input shaft bearing should be heated in advance of the assembly procedure. Heating components will ease the assembly process. Place the input shaft bearing into the Gear/Bearing Heater. Make sure the bearing is heated to 150°C (302°F).
7. Using the Bearing Tube Remover/Installer with the Bearing Tube Removal Screw, Transmission Bearing Collet Remover/Installer and the Bearing Collet Sleeve Remover, remove the input shaft pocket bearing.
- Inspect the bearing for wear or damage. Install a new bearing as necessary.
8. Remove and discard the snap ring.
9. Using the 2 or 3 Jaw Puller, Shaft Protector Set and the Bearing Puller, remove the 3rd and 4th synchronizer assembly and 3rd gear.
- Inspect 3rd gear for wear or damage. Install a new gear as necessary.
10. Disassemble the 3rd and 4th synchronizer assembly.
- Inspect the components for wear or damage. Install new components as necessary.
11. Check the clearance between the synchronizer ring and the gear.
1. Place the synchronizer ring onto the synchronizer sliding sleeve. Position the synchronizer ring on the gear.
2. Insert a feeler gauge and measure the clearance, while applying pressure and rotating the synchronizer ring. The clearance should be the same around the entire circumference.
- Place the feeler gauge between the ring and gear clutching teeth. The ring has a raised section, inserting the feeler gauge past the teeth will give an incorrect reading.
- If the clearance is less than 1.0 mm (0.039 in), install a new synchronizer assembly.
12. Remove the mainshaft needle bearing.
- Inspect the bearing for wear or damage. Install a new bearing as necessary.
13. NOTE: When installing the Bearing Puller, make sure it is installed above the mainshaft bearing race.
Using the 17.5 Ton Press and the Bearing Puller, press the mainshaft gear bushing off the mainshaft.
14. Using the 17.5 Ton Press and the Bearing Puller, press the mainshaft 2nd gear thrust washer, the mainshaft 2nd gear, the mainshaft needle bearing, the mainshaft gear bushing, 1st and 2nd synchronizer assembly and mainshaft 1st gear.
- Inspect the gears and bearing for wear or damage. Install new components as necessary.
15. Remove the mainshaft 1st gear needle bearing.
- Inspect the bearing for wear or damage. Install a new bearing as necessary.
16. Using the 17.5 Ton Press and the Bearing Puller, remove the mainshaft center bearing.
- Inspect the bearing for wear or damage. Install a new bearing as necessary.
17. Disassemble the 1st and 2nd synchronizer assembly.
- Inspect the components for wear or damage. Install a new synchronizer assembly as necessary.
18. Check the clearance between the synchronizer ring and the gear clutching teeth.
1. Place the synchronizer ring onto the synchronizer sliding sleeve. Position the synchronizer ring on the gear.
2. Insert a feeler gauge and measure the clearance, while applying pressure and rotating the synchronizer ring. The clearance should be the same around the entire circumference.
- Place the feeler gauge between the ring and gear clutching teeth. The ring has a raised section, inserting the feeler gauge past the teeth will give an incorrect reading.
- If the clearance is less than 1.0 mm (0.039 in), install a new synchronizer assembly.
19. NOTICE: To prevent damage, do not heat bearings, thrust washers, bushings or the synchronizer bodies higher than 150°C (302°F).
New or original components should be heated in advance of the assembly procedure. Heating the specified components will ease the assembly process. Place the input shaft pocket bearing, the mainshaft second gear thrust washer, the mainshaft center bearing, the synchronizer bodies and the mainshaft gear bushings into the Gear/Bearing Heater.
Assembly
1. Carry out the following:
- Inspect and install new mainshaft gears if chipped, burred or badly worn.
- Check the mainshaft gear end play. Install a new gear if the end play is not within specification.
- Inspect and install a new mainshaft if it is out of round or worn, if the bearing surface is scored or the splines are worn or damaged.
- Inspect and install a new speedometer drive gear if the gear teeth are worn or broken.
2. NOTICE: Do not reassemble the mainshaft dry. Apply lubricant throughout the assembly procedure or damage to the components can occur.
Lubricate all mainshaft components with the recommended transmission lubricant during reassembly.
3. Install the center mainshaft bearing.
- Make sure the bearing is installed against the stop on the mainshaft.
4. Using the 17.5 Ton Press and the Bearing Puller, position the mainshaft on the press with the input end facing upward.
- Using a hammer and punch, remove the bearing cup from the intermediate housing, then install it on the bearing. This will prevent any damage to the bearing during installation.
5. Install the 1st gear bearing and 1st gear.
6. Install the 3 synchronizer rings for 1st gear.
- Make sure the tabs on the synchronizer ring are in the slots on the gear.
- Make sure to align the notches on the synchronizer body with the tabs on the synchronizer ring.
7. Using the Thrust Washer Bearing Cup Remover/Installer, press the 1st and 2nd gear synchronizer body into place.
- The numbers on the synchronizer hub must face upward.
- Make sure to align the notches on the synchronizer body with the tabs on the synchronizer ring.
8. NOTE: Install the synchronizer sliding sleeve with the flats aligned with the detent notches.
Install the synchronizer sliding sleeve.
- The sliding sleeve has 3 flat areas which need to line up with the detent area of the synchronizer body.
9. Install the synchronizer spring and plate, then tilt the plate up and install the detent ball.
- If the springs are difficult to install, check the alignment of the synchronizer sliding sleeve flat areas.
10. NOTE: Position the synchronizer into the neutral position.
Install the synchronizer rings for 2nd gear.
- Align the tabs on the synchronizer rings with the slots in the synchronizer body.
11. Install the mainshaft 2nd gear bushing.
12. NOTE: Let the mainshaft 2nd gear bushing cool down for 2-4 minutes before trying to install the mainshaft needle bearing.
Install the mainshaft needle bearing.
13. Install the 2nd gear.
- Make sure to align the tabs on the synchronizer ring with the slots on the gear.
14. Using the Thrust Washer Guide and the Thrust Washer Bearing Cup Remover/Installer, press the mainshaft 2nd gear thrust washer into place.
15. Using a suitable tool, install the mainshaft 3rd gear bushing on the mainshaft.
- Pull the 1st/2nd gear sliding sleeve into the neutral position.
16. NOTE: Let the mainshaft 3rd gear bushing cool down for 2-4 minutes before trying to install the mainshaft needle bearing.
Install the mainshaft needle bearing.
17. Install the mainshaft 3rd gear and synchronizer ring.
18. Install the 3rd and 4th gear synchronizer body.
- The numbers on the synchronizer body must face upward.
- Make sure to align the synchronizer body notches with the tabs on the synchronizer ring.
19. Install a new snap ring.
- Install the snap ring with the small holes facing upward.
- The snap ring is a selective fit. The correct snap ring should completely fill the groove when seated.
20. NOTICE: Press the input shaft pocket bearing onto the mainshaft by the inner race only. Pressing on the outer race will damage the bearing.
Press the input shaft pocket bearing into place.
- Make sure the bearing is correctly seated. At the bottom of the bearing, there should be no gap. At the top of the bearing, check for a small amount of the mainshaft to be above the inner bearing race.
21. Remove the mainshaft from the press and reinstall it in the Gear Pack Fixture.
22. Install and position the synchronizer sliding sleeve down on the synchronizer body, install the springs and detents.
23. Install the synchronizer ring, then move the synchronizer sliding sleeve up on the synchronizer body.
24. NOTICE: Do not drive against the bearing cone. Drive against the inner race only or damage to the components can occur.
Using a suitable driver, install a new input shaft bearing.
- Seat the bearing against its stop.
25. Using the Wheel Speed Sensor Ring Installer, install the input shaft rear oil dam.
- Rotate the input shaft to make sure the input shaft rear oil dam is completely seated.
26. Install the input shaft.
- Fill the input shaft pocket with a suitable engine assembly white grease.
27. NOTE: If the following axial gear clearances are not within specification, it will be necessary to disassemble and reinspect.
Using the Dial Indicator Gauge with Holding Fixture and the Clutch Housing Gauge, check the axial gear clearance at the mainshaft 1st gear.
28. Using the Dial Indicator Gauge with Holding Fixture and the Clutch Housing Gauge, check the axial gear clearance at the mainshaft 2nd gear.
29. Rotate the mainshaft with the input shaft facing downward. Using the Dial Indicator Gauge with Holding Fixture and the Clutch Housing Gauge, check the axial gear clearance at the mainshaft 3rd gear.
