6. Synchronizers Cleaning and Inspection
Synchronizers Cleaning and InspectionImportant: When you service the synchronizers, retain in order the components that you remove.
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. The 3rd and 4th gear synchronizer hub must have a force fit on the mainshaft splines.
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 problems.
5. Replace a worn hub.
6. 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
7. Inspect the inserts and struts for wear or damage.
8. Inspect the mainshaft drive gear clutching cones for synchronizer ring metal transfer.
9. Inspect the synchronizer sleeve teeth (1) for the following which may cause shift problems:
^ Grated teeth
^ Chipped off teeth
^ Blunted teeth
10. Inspect the synchronizer sleeve detent stops (2) for wear or being chipped off.
11. Replace the synchronizer assembly if the teeth or stops show the above conditions.
12. Inspect the 1st/2nd synchronizer blocker rings for worn away grooves.
13. Replace the blocker ring assembly if the blocker ring grooves are worn away.
14. Inspect the synchronizer blocker rings for worn shift teeth.
15. Inspect the center ring for being warped or damaged.
16. Inspect the inner ring for worn grooves.
17. Replace the synchronizer ring assembly for any of the above conditions.
18. Measure the cap between the vertical faces of the blocking ring teeth and the synchronizer clutch gear as follows:
18.1. Assemble the correct blocker ring to the correct gear.
18.2. Apply pressure to the blocker ring to fully seat the ring.
18.3. 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 inch)
^ 2nd gear 2.16 - 1.14 mm (0.085 - 0.045 inch)
^ 3rd gear 1.73 - 0.76 mm (0.068 - 0.030 inch)
^ 4th gear 2.10 - 1.19 mm (0.079 - 0.047 inch)
^ Overdrive gear 1.83 - 1.07 mm (0.072 - 0.042 inch)
^ Reverse gear 2.24 - 1.47 mm (0.088 - 0.058 inch)
19. If using a NEW blocker ring and the standard clearance can not be obtained replace the gear.