Chevrolet Silverado / GMC Sierra. Service manual — part 2593

TRANSMISSION NOISY

Diagnostic Aids

9

Transmission Fluid Replacement.
Do the gears still clash?

Go to Step 9

System OK

10

Inspect for the correct type of transmission
fluid.
Is the correct type of transmission fluid being
used?

Go to Step 12

Go to Step 11

11

Drain the transmission fluid and fill the
transmission with the correct type of fluid.
Refer to Transmission Fluid Replacement.
Did you find and repair the condition?

System OK

Go to Step 12

12

1. Remove the transmission. Refer to

Transmission Replacement.

2. Disassemble the gear shift components.

3. Inspect the gear shift components and/or

synchronizers for damage or wear.

Are the gear shift and/or synchronizers worn or
damaged?

Go to Step 13

Go to Step 14

13

1. Replace worn and/or damaged

components, as necessary.

2. Inspect for other gear train damaged

components, as necessary.

Did you find and repair the condition?

System OK

Go to Step 14

14

Inspect the clutch pilot bearing for binding.
Is the pilot bearing binding?

Go to Step 15

System OK

15

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?

Go to Step 16

Go to Diagnostic

Aids

16

Operate the system and verify the repair.
Did you correct the condition?

System OK

Go to Step 1

2008 Chevrolet Silverado 1500

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

The manual transmission can be noisy for a number of reasons. It can be noisy in neutral, low,
high, and/or reverse gear. Diagnose the transmission, including the level of fluid and the correct
type of fluid in the transmission. Inspect for misalignment or loose bolts to the engine. The
transmission could be noisy internally. Gears, synchronizers, and bearings should be inspected for
worn or damaged components. These are only a few areas that may cause the transmission to be
noisy. You should inspect all possibilities that could lead you to the noise of these concerns.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

2: This step inspects for the correct fluid level.

4: This step inspects for the correct type of transmission fluid.

10: This step is inspects for internal damage or worn components.

Step

Action

Yes

No

DEFINITION: The transmission is noisy and the noise carries into the passenger
compartment.

1

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

Go to Step 2

Go to Symptoms
- Manual
Transmission

2

Inspect the transmission fluid level.
Is the fluid level correct?

Go to Step 4

Go to Step 3

3

Add transmission fluid. Refer to Transmission
Fluid Replacement.
Is the transmission noisy?

Go to Step 4

System OK

4

Inspect the transmission for the correct type of
fluid.
Is the transmission fluid the correct type?

Go to Step 6

Go to Step 5

5

Drain the transmission fluid and fill the
transmission with the correct type of fluid.
Refer to Transmission Fluid Replacement.
Did you find and repair the condition?

System OK

Go to Step 6

6

Inspect the shift control closeout boot.
Is the closeout boot loose or damaged?

Go to Step 7

Go to Step 8

7

Position and tighten the shift tower to
specification or replace the shift control
closeout boot, as necessary.
Did you find and repair the condition?

System OK

Go to Step 8

2008 Chevrolet Silverado 1500

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

TRANSMISSION JUMPS OUT OF GEAR

Diagnostic Aids

You should perform a static shift test and a dynamic shift test. The manual transmission can have
many conditions that make it jump out of gear. Some of the most common conditions are
misalignment of the transmission to engine, a loose clutch housing, or misalignment. The
transmission should also be inspected for worn or damaged input bushing to flywheel or worn or
damaged input and output shaft bearings. A bent input shaft could also be the result of the
transmission jumping out of gear. While inspecting the internal part of the transmission, also
inspect for worn detent springs, synchronizers, worn teeth on the gears, or worn thrust washers.

Inspect all internal components for being worn or damaged.

8

Inspect the clutch housing for loose bolts and/or
misalignment with the engine.
Did you find any loose bolts or misalignment
with the engine?

Go to Step 9

Go to Step 10

9

Inspect the shift tower boot.
Is the closeout boot loose or damaged?

Go to Step 10

Go to Step 11

10

1. Remove the transmission. Refer to

Transmission Replacement.

2. Disassemble and inspect the following

transmission components for wear or
damage:

Gear shift

Transmission gears

Bearings

Did you find any wear or damage?

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

2008 Chevrolet Silverado 1500

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

Test Description

The numbers below refer to the step numbers on the diagnostic table.

2: This step inspects for the shift control closeout boot position.

6: This step inspects for worn or damaged transmission or engine mounts.

12: This step inspects for worn or damaged internal components.

Step

Action

Yes

No

DEFINITION: Gear disengagement occurs during normal operation.

1

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

Go to Step 2

Go to Symptoms
- Manual
Transmission

2

Inspect the transmission shift tower.
Is the boot out of position?

Go to Step 3

Go to Step 3

3

Reposition or replace the shift tower.
Did you find and repair the condition?

System OK

Go to Step 4

4

Inspect the transmission shift control.
Is the shift lever loose or damaged?

Go to Step 5

Go to Step 6

5

Replace the transmission shift lever. Refer to
Transmission Control Lever Knob
Replacement and Transmission Control
Lever Boot Replacement .
Did you find and repair the condition?

System OK

Go to Step 6

6

Inspect the engine and/or transmission mounts.
Are the engine and/or transmission mounts worn
or damaged?

Go to Step 7

Go to Step 8

7

Replace the engine mounts and/or transmission
mounts. Refer to the appropriate procedure:

Engine Mount Replacement - Left Side

Engine Mount Replacement - Right
Side

Transmission Rear Mount
Replacement

Did you find and repair the condition?

System OK

Go to Step 8

2008 Chevrolet Silverado 1500

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