GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Cobalt 🢒 Transmission/Transaxle 🢒 Manual Transaxle - MU3 🢒 Transmission Noisy

Test Description

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

  1. This step inspects for vibration causing a noise. If the vehicle is carrying a certain load, the driveline axle may not be correct, and could cause a vibration. The vibration maybe resonating into the transaxle, causing a noise.

    2.

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

  3. This step inspects for the correct type of transaxle fluid. The transaxle uses a special fluid. If the incorrect fluid was used, there may have been an overheating problem. Overheating may cause damage to the transaxle components.

    4.

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

    5.

  5. This step tests to determine if clutch components are making the noise. Depress 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 transaxle component is faulty.

Step

Action

Yes

No

DEFINITION: The transaxle is making a noise. The different noises may be a whine or a growl from faulty bearings or gears. The noise may also be caused from a faulty component causing a vibration noise or rattle.

1

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

Go to Step 2

Go to Symptoms - Manual Transmission

2

Is the noise present at a certain road speed, or with a certain load?

Go to Step 3

Go to Step 4

3

Inspect for the correct driveline angle. Refer to Diagnostic Starting Point - Vibration Diagnosis and Correction .

Did you find and repair the condition?

Go to Step 17

Go to Step 4

4

Is the noise present in all gears?

Go to Step 6

Go to Step 5

5

Is the noise present in just one gear?

Go to Step 16

Go to Step 6

6

Inspect the transaxle fluid level.

Is the fluid level correct?

Go to Step 8

Go to Step 7

7

Add transaxle fluid. Refer to Transmission Fluid Replacement .

Did you find and repair the condition?

Go to Step 17

Go to Step 8

8

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

Is the transaxle fluid the correct type?

Go to Step 10

Go to Step 9

9

Drain and refill the transaxle with the correct type fluid. Refer to Transmission Fluid Replacement .

Did you find and repair the condition?

Go to Step 17

Go to Step 10

10

Inspect the shift tower boot.

Is the closeout boot loose or damaged?

Go to Step 11

Go to Step 12

11

Position and tighten the shift tower boot to specifications. Refer to Shift Control Cable Replacement .

Did you find and repair the condition?

Go to Step 17

Go to Step 12

12
  1. Inspect for engine to transaxle alignment.
  2. Inspect for loose transaxle mounting bolts.

Are there any loose transaxle mounting bolts?

Go to Step 13

Go to Step 14

13

Replace and tighten the transaxle mounting bolts. Refer to Transmission Replacement .

Is the noise still present?

Go to Step 14

Go to Step 17

14

With the engine operating, depress the clutch pedal.

Is the noise still present?

Go to Step 15

Go to Step 16

15
  1. Remove the clutch. Refer to Clutch Pressure and Driven Plate Replacement .
  2. Inspect the following components for being the cause of the noise.
    3. • The release bearing
    • The pilot bearing
    • 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 17

Go to Step 16

16
  1. Remove the transaxle. Refer to Transmission Replacement .
  2. Disassemble the transaxle. Refer to Transmission Disassemble . Use the information in the Cleaning and Inspection section to determine if any of the transaxle components are faulty.

Did you find and repair the condition?

Go to Step 17

--

17

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 1