Mainshaft
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. 3rd-4th synchronizer assembly, blocking ring and 3rd gear
- Scribe an alignment mark on both the 3-4 synchronizer hub and sleeve. Use these marks for correct reassembly.
- Using a hydraulic press and the puller plate, remove the 3-4 synchronizer assembly and the 3rd gear.
Bearing and gear puller: J-22912-01
2. Needle bearing and spacer
3. Snap ring
- Second gear snap ring, using a pair of snap ring pliers.
4. Thrust washer
5. 2nd gear, bearing and spacer
6. Spiral retaining ring
- Spiral retaining ring, using a pocket screwdriver.
7. Thrust washer and 2nd blocking ring assembly (inner cone, outer cone race & 1-2 blocking ring)
8. Spring, reverse sliding gear, insert and pin
- Scribe an alignment mark on both the shaft and hub and reverse sliding gear. Use these marks for correct reassembly.
- Remove the reverse sliding gear from shaft and, along with these parts:
- The three keys
- One of the two springs
NOTE: Do not attempt to remove the 1-2 synchronizer hub from the mainshaft.
The hub and shaft are permanently assembled and machined as a matched set.
9. 5th driving gear
- Using a hydraulic press and the puller plate, remove the fifth driving gear from the mainshaft.
Bearing and gear puller: J-22912-01
10. Mainshaft rear bearing
Remove the mainshaft rear bearing from the shaft.
11. 1st gear
12. 1st gear bearing and sleeve
13. 1st blocking ring assembly
- Remove the three-piece first blocking ring assembly. Also remove the remaining synchronizer spring.
14. Mainshaft (with 1-2 hub)
REASSEMBLY
14. Mainshaft (with 1-2 hub)
8. Spring, reverse sliding gear, insert and pin
- Assemble the three synchronizers. Make sure that the hubs and sleeves are matched and that the inserts are installed properly. Attach the hooked ends of the springs to the same inserts and install them in opposite directions. Also align blocking rings with inserts during installation steps.
NOTE: Soak the paper-lined blocking rings in Dexron II(R) before installing them.
13. 1st blocking ring assembly
- Install the three-piece blocking ring assembly for 1st speed.
12. 1st bearing sleeve and bearing
11. 1st gear
- Make sure blocking rings align with inserts.
10. Mainshaft rear bearing
9. 5th driving gear and snap ring
- Using a hydraulic press and the installer, install the 5th driving gear on the mainshaft. Support the mainshaft with the mainshaft support.
Installer: J-25234
Mainshaft support: J-5590
- While the mainshaft is still on the press bed, install the snap ring for the fifth driven gear. If it does not fit, continue pressing the 5th driving gear until it is fully seated.
7. 2nd blocking ring assembly and thrust washer
- Install the three-piece blocking ring assembly for 2nd speed.
- Install the thrust washer for the blocking ring inner cone.
6. Spiral retaining ring
- Spiral snap ring installer: J-37360
5. 2nd speed gear spacer, bearing and 2nd gear
4. Thrust washer
3. Snap ring
2. 3rd gear spacer and needle bearing
1. 3rd gear, blocking ring and 3rd-4th synchronizer assembly (Hub, insert, sleeve & spring)
- Install the 3rd speed blocking ring.
- Install the 3-4 synchronizer hub. Use a hydraulic press and installer to press the hub onto the mainshaft. Be sure to align the blocking ring with the synchronizer inserts while installing the hub.
Synchronizer & gear installer: J-37372