11. Synchronizers Cleaning and Inspection

Synchronizers Cleaning and Inspection

If you are servicing this transmission for a shifting concern such as clash, hop out of gear, or block-out in a particular gear, the following hardware must be replaced as a set for the gear in question. Adjoining gears do not need to be serviced unless necessary:

* Main gear in question - for example 2nd, 3rd
* Synchronizer assembly, sleeve assembly
* Blocker ring assembly
* Shift fork inserts





Important: When you service the synchronizers, retain them in the order that they are removed. Mark the parts to ensure the correct position for inspection and assembly.


1. Clean all the synchronizer parts in a suitable cleaning solvent and air dry all the parts.
2. Inspect the 1st/2nd gear and the 3rd/4th gear synchronizer hubs for a force fit on the output shaft.
3. Replace synchronizer hubs that do not require a force fit.
4. Inspect the synchronizer hub for wear on the external splines. A stepped effect on the teeth, due to wear, may cause shift concerns.
5. Replace a worn hub.
6. Correct the cause, such as, but not limited to the following conditions:

* Engine related vibrations
* Driving at a low speed in a high gear
* Defective vibration damper or crankshaft




7. Inspect the synchronizer sleeve teeth (a) for the following conditions, which may cause shift concerns:

* Grated teeth
* Chipped off teeth
* Blunted teeth

8. Inspect the synchronizer sleeve detent stops (b) for wear or for being chipped off.
9. Replace the synchronizer assembly if the teeth or stops show the above conditions.




10. Inspect the synchronizer blocker rings for worn away grooves (a).
11. Replace the blocker ring assembly if the blocker ring grooves are worn.




12. Inspect the synchronizer blocker rings for worn shift teeth.
13. Inspect the internal ring for being warped or damaged.
14. Inspect the outer ring for worn grooves.
15. Replace the synchronizer assembly for any of the above conditions.




16. Install the synchronizer blocking rings to the correct speed gear.
17. Inspect the braking effect of the blocking ring. Turn the blocking ring in one direction while pushing to the gear cone. Ensure the ring locks.
18. If the ring does not lock, replace the synchronizer assembly.




19. Except for 5th gear, measure the blocker ring to gear clearance.

1. Assemble the correct blocker ring to the correct gear.
2. Apply pressure to the blocker ring to fully seat the ring.
3. Using a feeler gauge, measure between the blocker ring teeth and the teeth on the gear.

* Minimum Clearance 4th Gear: 0.8 mm (0.031 in)
* Minimum Clearance 3rd Gear: 0.8 mm (0.031 in)
* Minimum Clearance 2nd Gear: 0.8 mm (0.031 in)
* Minimum Clearance 1st Gear: 0.8 mm (0.031 in)

20. If using a NEW blocker ring and the standard clearance can not be obtained, replace the gear.




21. Install the reverse synchronizer inner ring, internal ring, and outer ring to the 5th synchronizer ring.
22. Inspect the braking effect of the blocking ring. Turn the reverse outer ring in one direction while pushing to the 5th synchronizer ring. Ensure the ring locks.
23. If the ring does not lock, replace the synchronizer assembly.




24. Inspect the pressure pieces for wear or damage.
25. Inspect the springs for distortion.
26. Replace the worn pressure pieces or faulty springs.




27. Inspect the springs for distortion.
28. Inspect the inserts for wear.
29. Replace any worn components.