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For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2001 🢒 Firebird 🢒 Transmission/Transaxle 🢒 Manual Transmission - M49 🢒 Transmission Gear Clash When Shifting Gears

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.

  1. This step test for proper clutch operations.

    2.

  2. This step test for air in the hydraulic clutch system.

    3.

  3. 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.

1

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

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 Oil Drain and Fill .

Did you find and repair the condition?

System OK

Go to Step 10

10

  1. Remove the transmission. Refer to Transmission Replacement .
  2. Disassemble and inspect the gear shift components and/or synchronizers for damage or wear. Refer to Transmission/Transaxle/Transfer Case Unit Repair Manual.

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

Go to Step 11

Go to Step 12

11
  1. Replace worn and/or damaged components as necessary.
  2. Install the transmission. Refer to Transmission Replacement .

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

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