Synchronizer Assembly Inspection

Synchronizer Assembly Inspection





1. Inspect the wear of the cone area. After matching synchronizer ring to gear, measure as shown in figure. Replace if it is below limit.

Specifications:
^ The standard clearance between the gear and ring is 1 mm (0.039 inch).
^ The clearance limit between the gear and ring is 0.5 mm (0.020 inch).





2. Inspect the cone contact condition. When synchronizer mechanism is abnormal in operation, connection between ring inner surface and gear cone area is considered to be partially defective in spite of correct clearance between gear and ring. Therefore, cone area and ring inner surface shall be inspected. In this case, ring inner surface shall be glossy. Black area is abnormal and if inspection is difficult, inspect after applying red lead. Cone area can be worn in wave form.





3. Inspect the key slot width of synchronizer ring. Measure key slot width of synchronizer ring. Replace if it exceeds the limit.

Specifications:
^ The standard key slot width for 1st gear is 9.6 mm (0.378 inch).
^ The limit key slot width for 1st gear is 10 mm (0.394 inch).
^ The standard key slot width for 2nd, 3rd, and 4th gear is 9.6 mm (0.378 inch).
^ The limit key slot width for 2nd, 3rd, and 4th gear is 10 mm (0.394 inch).
^ The standard key slot width for 5th gear is 9.4 mm (0.370 inch).
^ The limit key slot width for 5th gear is 9.8 mm (0.386 inch).





4. Inspect for worn or damaged synchronizer ring teeth. Replace it if necessary.





5. Inspect for worn synchronizer key (2).
6. Inspect for weak, damaged or broken spring (1).