GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 Sierra Denali 🢒 Transmission 🢒 Manual Transmission - Tremec 5-Speed (M96) 🢒 Transmission Gear Clash When Shifting Gears

Diagnostic Aids

Gear clash is a grinding noise that is made while shifting gears. You should perform a static shift and dynamic shift test. If the transmission develops gear clash, first inspect the clutch adjustment or for a 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, remove the transmission and 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 numbers below refer to the step numbers on the diagnostic table.

  1. This step inspects for proper clutch operations.

    2.

  2. This step inspects for air the hydraulic clutch system.

    3.

  3. This step inspects for worn or damaged internal components.

Step

Action

Yes

No

DEFINITION: The transmission gears clash while shifting from one gear into another gear.

1

Did you review the Symptoms - Manual Transmission and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Manual Transmission

2

Inspect for proper clutch operation. Refer to Symptoms - Clutch .

Does the clutch operate properly?

Go to Step 3

Go to Step 3

3

Verify that the clutch is releasing properly. Refer to Clutch System Description and Operation .

Is the clutch releasing properly?

Go to Step 5

Go to Step 4

4

Repair the clutch system. Refer to Clutch Assembly Replacement .

Did you find and repair the condition?

System OK

Go to Step 5

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 .

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 shift tower. Refer to Transmission Control Replacement .

Did you find and repair the condition?

System OK

Go to Step 9

9

Inspect the transmission fluid level. Refer to Transmission Fluid Replacement .

Do the gears still clash?

Go to Step 9

System OK

10

Inspect for the correct type of transmission fluid.

Is the correct type of transmission fluid being used?

Go to Step 12

Go to Step 11

11

Drain the transmission fluid and fill the transmission with the correct type of fluid. Refer to Transmission Fluid Replacement .

Did you find and repair the condition?

System OK

Go to Step 12

12

  1. Remove the transmission. Refer to Transmission Replacement .
  2. Disassemble the gear shift components.
  3. Inspect the gear shift components and/or synchronizers for damage or wear.

Are the gear shift and/or synchronizers worn or damaged?

Go to Step 13

Go to Step 14

13
  1. Replace worn and/or damaged components, as necessary.
  2. Inspect for other gear train damaged components, as necessary.

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

System OK

15
  1. Replace the clutch pilot bearing. Refer to Clutch Pilot Bearing Replacement .
  2. Install the transmission. Refer to Transmission Replacement .

Did you find and repair the condition?

Go to Step 16

Go to Diagnostic Aids

16

Operate the system and verify the repair.

Did you correct the condition?

System OK

Go to Step 1