Reverse Gear and 5TH Gear
DISASSEMBLY
Note: The following "Steps" actually refer to parts in the figure above. Isuzu uses this figure and the "Steps" for disassembly and assembly.
1. Bearing snap ring (4X2)
- Use a pair of snap ring pliers to remove the bearing snap ring.
2. Ball bearing (4X2)
- Set the bearing remover to the bearing and the mainshaft end to remove the bearing.
Bearing remover: J-37217
Puller: J-37487
3. Bearing snap ring (4X2)
4. Speedometer drive gear (4X2)
5. Clip (4X2)
6. Retainer snap ring (4X2)
1. Oil Seal Collar (4X4)
2. Ball bearing (4X4)
7. Retainer
- Set the retaining ring remover to the retainer and the mainshaft end. (4X4)
- Remove the retainer together with the bearing and the oil seal collar. (4X4)
The universal puller may be used in place of the retaining ring remover.
Retainer Remover: J-37222
Puller: J-37487
8. Thrust plate
9. Thrust washer and lock ball
10. Reverse idler gear snap ring
- Use a pair of snap ring pliers to remove the snap ring.
11. Reverse idler gear assembly
- Remove the reverse idler gear assembly from the intermediate plate.
12. Idle shaft pin
13. Thrust washer
14. Reverse idler gear
15. Reverse idler shaft
16. Bearing snap ring
- Use a pair of snap ring pliers to remove the snap rings.
17. Ball bearing
18. Counter 5th gear
- Attach the bearing remover to the counter gear shaft.
- Use the bearing remover to remove the ball bearing and the counter 5th gear.
19. Counter reverse gear
20. 5th gear
21. 5th block ring
22. Needle bearing
- Remove the needle bearing (2 piece type).
23. Mainshaft nut
- Engage the 3rd-4th synchronizer with the 3rd gear.
- Engage the 1st-2nd synchronizer with the 1st gear.
- Attach the holding fixture to the mainshaft and the counter gear.
Holding fixture: J-37224
Base: J-3289-20
- Use the mainshaft nut wrench to remove the mainshaft nut.
Wrench: J-37219
24. Rev-5th synchronizer assembly
25. Reverse block ring
26. Reverse gear
- Use screw drivers between the reverse gear and bearing plate to remove the Rev-5th synchronizer assembly together with reverse block ring and gear.
27. Needle bearing
28. Bearing plate and screw
- Use the torx bit wrench to remove the bearing plate screw from the intermediate plate.
Torx bit wrench: J-37225 (T45).
29. Bearing snap ring
30. Intermediate plate
- Use the snap ring pliers (1) to remove the mainshaft bearing snap ring (1).
- Hold the snap ring open with the pliers.
- Push the intermediate plate toward the rear of the transmission to remove it.
The bearing snap ring will come free.
INSPECTION AND REPAIR
Refer to "TOP GEAR SHAFT, MAIN GEAR SHAFT, AND COUNTER GEAR" for inspection and repair.
REASSEMBLY
30. Intermediate plate
- Mesh the counter gear with the mainshaft assembly.
- Install the holding fixture to the mainshaft and the counter gear.
Holding fixture: J-37224
Holding fixture base: J-3289-20
- Place the holding fixture (with the mainshaft and the counter shaft) in a vise.
- Install the intermediate plate.
29. Bearing snap ring
28. Bearing plate and screw
- Apply recommended thread locking agents (LOCTITE 242) or its equivalent to each of the bearing plate screw threads.
- Tighten the screws to the specified torque.
Torx bit wrench: J-37225 (T45)
Torque: 15 N-m (11 lb-ft)
27. Needle bearing
26. Reverse gear
25. Reverse block ring
24. Rev-5th synchronizer assembly
1. Turn the clutch hub face (1) toward the sleeve groove (2) on the outer circumference.
2. Check that the inserts (3) fit snugly into the block ring insert grooves.
3. Check that the inserts springs (4) are fitted to the inserts as shown in the illustration.
4. Check that the clutch hub (5) and the sleeve (6) slide smoothly.
5. Install the synchronizer assembly to the mainshaft.
The clutch hub face (with the heavy boss) must be facing the reverse gear side.
23. Mainshaft nut
1. Mesh the 1st-2nd and 3rd-4th synchronizers with both the 1st and 3rd gears (double engagement).
This will prevent the mainshaft from turning.
2. Install the new mainshaft hub nut.
3. Use the mainshaft nut wrench to tighten the mainshaft nut to the specified torque.
Wrench: J-37219
Torque: 137 N-m (101 lb-ft)
4. Use a punch to stake the mainshaft nut.
22. Needle bearing
21. 5th block ring
20. 5th gear
19. Counter reverse gear
- Apply engine oil to the counter reverse gear and the reverse gear.
- Install the counter reverse gear to the counter gear.
The reverse gear projection must be facing the intermediate plate.
18. Counter 5th gear
- Install the counter 5th gear to the transmission.
17. Ball bearing
16. Bearing snap ring
- Select the snap ring which will provide the minimum clearance between the ball bearing and the snap ring.
Ball Bearing And Snap Ring Clearance:
Bearing Snap Ring Availability - MUA Transmission:
- There are six snap ring sizes available.
The snap rings are color-coded to indicate their thickness.
Ball bearing and snap ring clearance
Standard: 0 - 0.15 mm (0 - 0.0059 in)
- Use a pair of snap ring pliers to install the snap ring to the counter gear shaft.
The snap ring must be fully inserted into the counter gear shaft snap ring groove.
15. Reverse idler shaft
14. Reverse idler gear
13. Thrust washer
12. Idle shaft pin
11. Reverse idler gear assembly
10. Reverse idler gear snap ring
- Select the snap ring which will provide the minimum clearance between the intermediate plate and the snap ring.
Reverse Gear Snap Ring Availability - MUA Transmission:
- There are three snap ring sizes available. The snap rings are color-coded to indicate their thickness.
Intermediate plate and snap ring clearance
Standard: 0 - 0.15 mm (0 - 0.0059 in)
- Use a pair of snap ring pliers to install the snap ring to the reverse idler shaft.
The snap ring must be fully inserted into the reverse idler shaft snap ring groove.
9. Thrust washer and lock ball
- Use a thickness gauge to measure the clearance between the 5th gear and the thrust washer.
- Measure clearance "A".
- Select appropriate thrust washer from chart.
- There are four thrust washer sizes available.
Thrust Washer Availability - MUA Transmission:
- The thrust washers are color-coded to indicate their thickness.
- Apply grease to the thrust washer and the lock
- Install the thrust washer and the lock ball.
8. Thrust plate
7. Retainer
6. Retaining snap ring (4X2)
5. Clip (4X2)
4. Speedometer drive gear (4X2)
3. Bearing snap ring (4X2)
2. Ball bearing (4X2)
- Use the installer to install the ball bearing to the mainshaft.
Installer: J-37223
1. Bearing snap ring (4X2)
2. Ball bearing (4x4)
- Apply engine oil to the bearing inner and outer circumference.
- Use the installer to install the ball bearing to the mainshaft in proper direction.
Installer: J-37223
1. Oil seal collar (4X4)