Diagnostic Aids
Gear clash is a grinding noise that is made when shifting gears. You should perform a static shift 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 all right, 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.
Test Description
The number(s) below refer to the step number(s) 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 | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: The transmission gear clash when shifting from one gear into another gear. | ||||
1 | Test for proper clutch operation. Does the clutch operate properly? | -- | Go to Step 2 | Go to |
Test for proper clutch operation. Does the clutch operate properly? | -- | Go to Step 4 | Go to Step 3 | |
3 | Verify that the clutch is releasing properly. Is the clutch releasing properly? | -- | Go to Step 5 | Go to Step 4 |
4 | Repair the clutch system. Did you find and repair the condition? | -- | System OK | Go to Step 5 |
Test for air in the clutch hydraulic system. Is there air in the hydraulic system? | Go to Step 6 | Go to Step 7 | ||
6 | Bleed the clutch hydraulic system. Refer to Hydraulic Clutch Bleeding in Clutch. Did you find and repair the condition? | -- | System OK | Go to Step 7 |
7 | Inspect the transmission control for wear. Is the transmission control worn? | -- | Go to Step 8 | Go to Step 9 |
8 | Replace the transmission control. Refer to Shift Control Assembly Replacement . Did you find and repair the condition? | -- | System OK | Go to Step 9 |
9 | Inspect the transmission fluid level. Refer to Transmission Fluid Level Inspection . Did you find and repair the condition? | -- | System OK | Go to Step 10 |
10 | Inspect for the correct type transmission fluid. Is the correct type transmission fluid being used? | -- | Go to Step 12 | Go to Step 11 |
11 | Drain and refill the transmission. Refer to Transmission Oil Drain and Fill . Did you find and repair the condition? | -- | System OK | Go to Step 12 |
Are the gear shift and/or synchronizers worn or damaged? | -- | Go to Step 13 | Go to Step 14 | |
13 |
Did you find and repair the condition? | -- | System OK | Go to Step 14 |
14 | Inspect the clutch pilot bearing for binding. Is the pilot bearing binding? | -- | Go to Step 15 | -- |
15 |
Did you find and repair the condition? | -- | Go to Step 16 | Go to Diagnostic Aids |
16 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 1 |
