Chevrolet Silverado / GMC Sierra. Service manual — part 2595

TRANSMISSION CLUNK ON ACCELERATION OR DECELERATION

Diagnostic Aids

There are a few factors to know when there is a clunk in acceleration or deceleration. You should
always inspect the engine mounts for being loose or damaged. Inspect for a worn or damaged
clutch driven plate. The clunk noise may also come from worn or damaged universal joints.

Test Description

The number below refers to the step number on the diagnostic table.

2: This step inspects for loose or damaged engine mounts.

4: This step inspects for a worn or damaged clutch driven plate.

6: This step inspects for worn or damaged universal joints.

10

Disassemble and inspect the transmission for an
incorrectly assembled or broken shift
mechanism.
Did you find an incorrectly assembled or
broken shift mechanism?

Go to Step 11

System OK

11

1. Replace worn or damaged components, as

necessary.

2. Install the transmission. Refer to

Transmission Replacement.

Did you find and repair the condition?

Go to Step 12

Go to Diagnostic

Aids

12

Operate the system in order to verify the repair.
Did you correct the condition?

System OK

Go to Step 1

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 .
Did you find loose or damaged engine mounts?

Go to Step 3

Go to Step 4

1. Tighten the engine mounts to

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Manual Transmission - Tremec 5-Speed (TZ0)

REPAIR INSTRUCTIONS - ON VEHICLE

TRANSMISSION REAR MOUNT REPLACEMENT

Removal Procedure

3

specifications. Refer to Fastener
Tightening Specifications .

2. Replace the engine mounts. Refer to

Engine Mount Replacement - Left Side
or Engine Mount Replacement - Right
Side .

Did you find and repair the condition?

System OK

Go to Step 4

4

1. Remove the transmission. Refer to

Transmission Replacement.

2. Inspect the clutch driven plate hub for

wear or damage.

Is the clutch driven plate worn or damaged?

Go to Step 5

System OK

5

1. Replace the clutch driven plate. Refer to

Clutch Assembly Replacement .

2. Install the transmission. Refer to

Transmission Replacement.

Did you find and repair the condition?

System OK

Go to Step 6

6

Inspect the universal joints for wear or damage.
Are the universal joints worn or damaged?

Go to Step 7

System OK

7

Replace the universal joints. Refer to Universal
Joint Replacement - Nylon Injected Ring or
Universal Joint Replacement - External
Snap Ring .
Did you find and repair the condition?

Go to Step 8

Go to Diagnostic

Aids

8

Operate the system in order to verify the repair.
Did you correct the condition?

System OK

Go to Step 1

NOTE:

Broken or deteriorated mounts can cause misalignment and
destruction of certain drive train components. When a single mount

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Manual Transmission - Tremec 5-Speed (TZ0)

Fig. 5: Transmission Mount To Crossmember Nut
Courtesy of GENERAL MOTORS CORP.

1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle .

2. Remove the transmission mount to crossmember nut (1).

breaks, the remaining mounts are subjected to abnormally high
stresses.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Manual Transmission - Tremec 5-Speed (TZ0)

Fig. 6: Identifying Transmission Mount To Transmission Bolts
Courtesy of GENERAL MOTORS CORP.

3. Remove the transmission mount to transmission bolts.

4. Raise the transmission just enough in order to permit removal of the mount using a suitable

transmission jack.

5. Remove the transmission mount.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Manual Transmission - Tremec 5-Speed (TZ0)