Gear clash is a grinding noise made when shifting gears. You should perform a static shift test and a dynamic shift test. If the transmission develops gear clash, first check the clutch adjustment or faulty clutch condition. A clutch that drags or does not fully engage is the most common cause of gear clash. If the clutch is at fault, the clash should occur in every gear. If the clutch is operating properly, or the clash does not occur in all gears, inspect for worn or damaged synchronizers, including the sleeves, hubs and the blocking rings. Also inspect for loose mounting bolts or misalignment.
The numbers below refer to the step numbers on the diagnostic table.
This step test for proper clutch operations.
This step test for air in the hydraulic clutch system.
This step inspects for worn or damaged internal components.
Step | Action | Yes | No |
---|---|---|---|
DEFINITION: The transmission gear clash when shifting from one gear into another gear. | |||
Test for proper clutch operation. Does the clutch operate properly? | Go to Step 3 | Go to Step 2 | |
2 | Repair the clutch system. Did you find and repair the condition? | System OK | Go to Step 3 |
Test for air in the clutch hydraulic system. Is there air in the hydraulic system? | Go to Step 4 | Go to Step 5 | |
4 | Bleed the clutch hydraulic system. Refer to Hydraulic Clutch Bleeding in Clutch. Did you find and repair the condition? | System OK | Go to Step 5 |
5 | Inspect the transmission control for wear. Is the transmission control worn? | Go to Step 6 | Go to Step 7 |
6 | Replace the transmission control. Refer to Shift Control Assembly Replacement . Did you find and repair the condition? | System OK | Go to Step 7 |
7 | Inspect the transmission fluid level. Refer to Transmission Fluid Level Inspection . Did you find and repair the condition? | System OK | Go to Step 8 |
8 | Inspect for the correct type transmission fluid. Is the correct type transmission fluid being used? | Go to Step 10 | Go to Step 9 |
9 | Drain and refill the transmission. Refer to Transmission Fluid Replacement . Did you find and repair the condition? | System OK | Go to Step 10 |
Are the gear shift and/or synchronizers worn or damaged? | Go to Step 11 | Go to Step 12 | |
11 |
Did you find and repair the condition? | System OK | Go to Step 12 |
12 | Inspect the clutch pilot bearing for binding. Is the pilot bearing binding? | Go to Step 13 | -- |
13 |
Did you find and repair the condition? | Go to Step 14 | Go to Diagnostic Aids |
14 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 1 |