Important: 

3rd/4th Speed Gear Synchronizer Disassembly

1. Lay the synchronizer on a shop towel, with the selector teeth down.
2. Cover with the shop towel.
3. Slide the synchronizer sleeve off the synchronizer hub.
4. Remove the three springs and the three inserts.

5th (Overdrive) Speed Gear Synchronizer Disassembly

1. Lay the 5th speed gear assembly on a shop towel, with the gear side down.
2. Cover with the shop towel.
3. Slide the synchronizer sleeve off the synchronizer hub.
4. Remove the three springs and the three inserts.

1st/2nd Speed Gear Synchronizer Disassembly

1. Lay the 1st/2nd speed gear assembly on a shop towel, with the 2nd speed gear side up. The tapered side of the sleeve is the 2nd speed gear side.
2. Cover with the shop towel.
3. Slide the synchronizer sleeve off the synchronizer hub.
4. Remove the four springs and the four inserts.

Reverse Speed Gear Synchronizer Disassembly

1. Lay the reverse speed gear assembly on a shop towel, with the reverse gear down.
2. Cover with the shop towel.
3. Slide the synchronizer sleeve off the synchronizer hub.
4. Remove the three springs and the three inserts.

1. Clean all the parts in a suitable cleaning solvent. Air dry all the parts.
2. Inspect the synchronizer sleeves for a sliding fit on the synchronizer hubs.
3. Replace the 3rd and 4th gear synchronizer hub that does not require a force fit on the mainshaft splines.
4. Inspect the synchronizer hub for wear on the external splines. A stepped effect on the teeth, due to wear, may cause shift conditions.
5. Inspect the 3rd and 4th gear synchronizer hub for a force fit on the mainshaft splines.
6. Replace a worn hub.
7. Correct the cause such as, but not limited to, the following:

•	Engine related vibrations

•	Driving at a low speed in a high gear

•	Defective vibration damper or crankshaft

•	Incorrectly set injector pump

8. Inspect the inserts and springs for wear or damage.



9. Inspect the mainshaft drive gear clutch gear teeth for wear.
10. Inspect the input shaft clutch gear teeth for wear.
11. Inspect the clutch gear for 4th gear, reverse gear, and overdrive gear wear.



12. Inspect the synchronizer sleeve teeth (1) for the following, which may cause shift conditions:

•	Grated teeth

•	Chipped off teeth

•	Blunted teeth

13. Inspect the synchronizer sleeve detent stops (2) for wear or for being chipped off.
14. Replace the synchronizer assembly if the teeth or stops show the above conditions.



15. Inspect the three-piece 1st/2nd synchronizer blocker rings for wear.
16. Replace the blocker ring assembly if the middle ring grooves are worn away.



17. Inspect all of the synchronizer blocker rings for worn shift teeth.
18. Inspect the blocker rings for worn friction material.
19. Replace the synchronizer ring assembly if any of the above conditions are present.



20. Measure the cap between the verical faces of the blocking ring teeth and the synchronizer clutch gear as follows:

20.1.

Assemble the correct blocker ring to the correct gear.

20.2.

Apply pressure to the blocker ring to fully seat the ring.

20.3.

Using a feeler gauge, measure between the blocker ring teeth and the teeth on the gear.

•	1st gear, between the hub and outer ring, 1.37-0.31 mm (0.054-0.012 in)

•	2nd gear 2.16-1.14 mm (0.085-0.045 in)

•	3rd gear 1.73-0.76 mm (0.068-0.030 in)

•	4th gear 2.10-1.19 mm (0.079-0.047 in)

•	Overdrive gear 1.83-1.07 mm (0.072-0.042 in)

•	Reverse gear 2.24-1.47 mm (0.088-0.058 in)

21. If a NEW blocker ring is used, and the standard clearance cannot be obtained, replace the gear.

3rd/4th Speed Gear Synchronizer Assembly

1. Lay the synchronizer hub on the 3rd speed gear synchronizer blocking ring and clutch gear. The ring and gear will hold the hub up.
2. Slide the synchronizer sleeve on the synchronizer hub.

•	Align the large tooth with the large slot in the sleeve.

•	The sleeve can go either direction, if it is not marked.

3. Using a small screwdriver, install the three springs and the three inserts.
4. Move the sleeve to the neutral position, to hold the springs and inserts in position.

5th (Overdrive) Speed Gear Synchronizer Assembly

1. Lay the 5th speed gear assembly, with the gear side down, on the workbench.
2. Slide the synchronizer sleeve on the synchronizer hub, with the tapered side of the sleeve towards the gear.
3. Using a small screwdriver, install the three springs and the three inserts.
4. Move the sleeve to the neutral position, to hold the springs and inserts in position.

1st/2nd Speed Gear Synchronizer Assembly

1. Lay the 1st/2nd speed gear assembly on the 1st speed gear synchronizer inner and middle rings. The rings will hold the hub up.
2. Slide the synchronizer sleeve on the synchronizer hub.

•	Align the sleeve to the hub.

•	The sleeve will fit in only one direction on the hub.

•	The tapered side of the sleeve faces up, or toward second gear.

3. Using a small screwdriver, install the four springs and the four inserts.
4. Move the sleeve to the neutral position, to hold the springs and inserts in position.

Reverse Speed Gear Synchronizer Assembly

1. Lay the reverse speed gear assembly, with the reverse gear down, on the workbench.
2. Slide the synchronizer sleeve on the synchronizer hub.

•	Align the sleeve to the hub.

•	The sleeve will fit in only one direction on the hub.

•	The tapered side of the sleeve faces toward reverse gear.

3. Using a small screwdriver, install the three springs and the three inserts.
4. Move the sleeve to the neutral position, to hold the springs and inserts in position.