GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

There are some easily remedied factors when trying to diagnosis the clutch when the clutch engages but slips while driving the vehicle. Check the clutch disc to make sure it is properly seated, or for worn facings on the disc plate. Also check for the disc to be covered in fluid. And check for worn or damaged clutch cover and weak diaphragm springs.

Test Description

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

  1. This step explains the parts and the operation of the clutch system.

  2. This step explains were to go to fix the fluid leak source.

  3. This step is check for worn facing or torn from the disc plate.

Step

Action

Yes

No

DEFINITION: The clutch engages but slips while driving the vehicle.

1

Did you review the clutch symptom operations and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Clutch

2

Make 30 to 40 normal starts. Do not over heat the clutch.

Does the clutch still slip?

Go to Step 3

System OK

3

  1. Remove the transmission. Refer to the following:
  2. •  Transmission Replacement in Manual Transmission NV-3500.
    •  Transmission Replacement in Manual Transmission NV-4500.
    •  Transmission Replacement in Manual Transmission ZFS6-650.
  3. Inspect the clutch disc.

Is the disc plate over heated?

Go to Step 4

Go to Step 5

4

Allow the disc plate to cool.

Does the clutch still slip?

Go to Step 5

System OK

5

Inspect the clutch disc in order to see if the disc is oil soaked.

Is the disc plate oil soaked?

Go to Step 6

Go to Step 7

6

Correct the leak at the source. And replace the clutch disc. Refer to Clutch Assembly Replacement .

Does the clutch still slip?

Go to Step 7

System OK

7

Inspect the clutch disc for a worn facing or if the facing is torn from the disc plate.

Is the facing worn or torn from the disc plate?

Go to Step 8

Go to Step 9

8

Replace the clutch disc. Refer to Clutch Assembly Replacement .

Does the clutch still slip?

Go to Step 9

System OK

9

Inspect for a weak diaphragm spring.

Is the diaphragm spring weak?

Go to Step 10

System OK

10

  1. Replace the disc plate. Refer to Clutch Assembly Replacement .
  2. Install the transmission. Refer to the following:
  3. •  Transmission Replacement in Manual Transmission NV-3500.
    •  Transmission Replacement in Manual Transmission NV-4500.
    •  Transmission Replacement in Manual Transmission ZFS6-650.
  4. Operate the system in order to verify the repair.

Did you and repair the condition?

System OK

Go to Diagnostic Aids

11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 1