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 inspects for worn or damaged shift control components.

  2. This step inspects for internal parts that may have been worn or damaged

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?

Go to Step 2

Go to Symptoms - Manual Transmission

2

Test the operation of the transmission shift control.

Is the control worn, binding, or damaged?

Go to Step 3

Go to Step 4

3

Replace the transmission shift control. Refer to Shift Control Assembly Replacement .

Did you find and repair the condition?

System OK

Go to Step 4

4

Inspect the hydraulic clutch operation and the clutch actuator.

Did you find and repair the condition?

Go to Step 9

Go to Step 5

5

  1. Remove the transmission. Refer to Transmission Replacement .
  2. Inspect the transmission input shaft and the clutch pilot bearing.

Is there signs of the input shaft binding in the pilot bearing?

Go to Step 7

Go to Step 8

6

  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?

System OK

Go to Step 8

7

Disassemble and inspect the following transmission internal components for wear or damage:

    • Gearshift components
    • Transmission gears
    • Bearing components

Are any of the components worn or damaged?

Go to Step 8

--

8

  1. Replace all worn or damaged components. Refer to Transmission/Transaxle/Transfer Case Unit Repair Manual.
  2. Install the transmission. Refer to Transmission Replacement .

Did you find and repair the condition?

Go to Step 9

Go to Diagnostic Aids

9

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 1