GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

All manual transmissions and axles have gear play that might cause a clunk. If the transmission is suspected of causing the clunk, compare it with a similar vehicle. An internal clunk in the transmission is the natural response of the driveline to an impact, but may also be caused by improper assembly, which would also cause other symptoms.

Step

Action

Yes

No

DEFINITION: A clunk is heard and/or felt on acceleration or deceleration.

1

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

Go to Step 2

Go to Symptoms - Manual Transmission .

2

Inspect the engine mounts for being loose or damaged. Refer to Engine Mount Inspection in Engine Mechanical - 3.6L (LY7).

Did you find and repair the condition?

Go to Step 7

Go to Step 3

3

Inspect the transmission mounts for being loose or damaged. Refer to Transmission Mount Replacement .

Did you find and repair the condition?

Go to Step 7

Go to Step 4

4

Inspect the transmission to engine fasteners for being loose or missing. Refer to Fastener Tightening Specifications .

Did you find and repair the condition?

Go to Step 7

Go to Step 5

5

Inspect the driveline for causing the clunk. Refer to Diagnostic Starting Point - Propeller Shaft .

Did you find and repair the condition?

Go to Step 7

Go to Step 6

6

Replace the transmission. Refer to Transmission Replacement .

Is the replacement complete?

Go to Step 7

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7

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 1