GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

When the manual transmission will not transmit power from the engine to the wheels and one gear will not shift it is possible that the gear is stripped. If the transmission will not shift in all gears it is possible that the input or countershaft gears are stripped or a broken input or output shaft has occurred. Sometimes the transmission shift control may not be working correctly.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step checks for worn or damage shift control components.

  2. This step inspects for any problems with the hydraulic system.

  3. This step inspects for internal parts that may have worn or damaged components.

Step

Action

Yes

No

DEFINITION: The transmission does not shift into a gear.

1

Did you review the manual transmission symptom and perform the necessary inspections?

Perform static and dynamic shift test.

Go to Step 2

Go to Symptoms - Manual Transmission

2

Are you able to shift into all gear positions?

Go to Step 4

Go to Step 3

3

Replace the transmission shift tower. Refer to Shift Tower Replacement .

Did you find and repair the condition?

Go to Step 12

Go to Step 4

4

Inspect the master cylinder for faulty operation.

Is the master cylinder faulty?

Go to Step 5

Go to Step 6

5

Replace the master cylinder. Refer to Master Cylinder Replacement .

Did you find a repair the condition?

Go to Step 12

Go to Step 6

6

Remove the transmission. Refer to Transmission Replacement .

Inspect the clutch actuator for wear or damage.

Is the clutch actuator worn or damaged?

Go to Step 7

Go to Step 8

7

Replace the clutch actuator. Refer to Clutch Concentric Actuator Cylinder Replacement .

Did you find and repair the condition?

Go to Step 12

Go to Step 8

8

Inspect the pilot bearing for wear or damage.

Is the pilot bearing worn or damaged?

Go to Step 9

Go to Step 10

9

Replace the pilot bearing. Refer to Clutch Pilot Bearing Replacement .

Did you find and repair the condition?

Go to Step 12

Go to Step 10

10

Disassemble the transmission. Refer to Transmission Disassemble . Inspect the following transmission internal components for wear or damage:

    • Gearshift components
    • Transmission gears
    • Bearings

Are any of the components worn or damaged?

Go to Step 11

Go to Diagnostic Aids

11

  1. Replace all worn or damaged components.
  2. Install the transmission. Refer to Transmission Replacement .

Did you find and repair the condition?

Go to Step 12

--

12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 1