GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2007 🢒 CTS 🢒 Transmission/Transaxle 🢒 Manual Transmission - Tremec 6-Speed 🢒 Transmission Noisy

Diagnostic Aids

If the transmission is in neutral with the engine operating, and a whirling noise - a neutral gear rattle is heard outside the vehicle, the sound is a normal condition.

Test Description

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

  1. This step inspects for the correct transmission fluid level. If the transmission fluid level is excessively low, damage may have occurred to the transmission components.

    2.

  2. This step inspects for the correct type of transmission fluid. If the incorrect fluid was used, there may have been an overheating condition. Overheating may cause damage to the transmission components.

    3.

  3. This step inspects for noise coming into the driver compartment. Improper sealing of the shift tower may be allowing normal transmission noise to be heard by the driver.

    4.

  4. This step tests to determine if clutch components are making the noise. Press the clutch pedal slowly and listen for the change in noise. If the noise changes while pressing the pedal, it may be a faulty clutch component. If the noise does not change until the clutch is completely disengaged, the transmission component is faulty.

Step

Action

Yes

No

DEFINITION: The transmission is making a noise. The noise may be a whine or a growl caused by faulty bearings or gears. The noise may also be caused from a faulty component causing a vibration noise.

1

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

Go to Step 2

Go to Symptoms - Manual Transmission

2

Is the noise present while in neutral, with the engine operating?

Go to Diagnostic Aids

Go to Step 3

3

Is the noise present in all gears?

Go to Step 5

Go to Step 4

4

Is the noise present in just one gear?

Go to Step 15

Go to Step 5

5

Inspect the transmission fluid level.

Is the fluid level correct?

Go to Step 7

Go to Step 6

6

Add transmission fluid. Refer to Transmission Fluid Replacement.

Did you find and repair the condition?

Go to Step 16

Go to Step 7

7

Inspect the transmission for the correct fluid type. Refer to Lubrication Specifications.

Is the transmission fluid the correct type?

Go to Step 9

Go to Step 8

8

Drain and fill the transmission with the correct type of fluid. Refer to Transmission Fluid Replacement.

Did you find and repair the condition?

Go to Step 16

Go to Step 9

9

Inspect the shift tower boot.

Is the closeout boot loose or damaged?

Go to Step 10

Go to Step 11

10

Position and tighten the shift tower boot to specifications. Refer to Transmission Control Lever Knob Replacement.

Did you find and repair the condition?

Go to Step 16

Go to Step 11

11

Inspect for loose transmission mounting bolts.

Are there any loose transmission mounting bolts?

Go to Step 12

Go to Step 15

12

Replace and tighten the transmission mounting bolts. Refer to Fastener Tightening Specifications.

Is the noise still present?

Go to Step 13

Go to Step 16

13

With the engine operating, press the clutch pedal.

Is the noise still present?

Go to Step 14

Go to Step 15

14
  1. Remove the clutch. Refer to Clutch Assembly Replacement.
  2. Inspect the following components for being the cause of the noise:
    3. • The release bearing
    • The pilot bearing
    • The dual mass flywheel, if equipped
    • The pressure plate
    • The clutch disc
    • The input shaft bearing
    • The engine crankshaft end play

Did you find and repair the condition?

Go to Step 16

Go to Step 15

15
  1. Remove the transmission. Refer to Transmission Replacement.
  2. Disassemble the transmission. Refer to one of the following: Transmission Disassemble. Use the information in the Cleaning and Inspection section to determine if any of the transmission components are faulty.

Did you find and repair the condition?

Go to Step 16

--

16

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 1