GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2007 🢒 Sierra Classic - 4WD 🢒 Transmission/Transaxle 🢒 Manual Transmission - NV 4500 🢒 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 equipped with an aftermarket box, or is carrying a certain load, the driveline axle may not be correct, and could cause a vibration. The vibration may be resonating into the transmission, causing a noise.

    2.

  2. 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.

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

    4.

  4. 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.

    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 transmission component is faulty.

Step

Action

Yes

No

DEFINITION: The transmission 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 Driveline Working Angles Measurement .

Did you find and repair the condition?

Go to Step 23

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 22

Go to Step 6

6

Inspect the transmission fluid level.

Is the fluid level correct?

Go to Step 8

Go to Step 7

7

Add transmission fluid. Refer to Transmission Fluid Replacement .

Did you find and repair the condition?

Go to Step 23

Go to Step 8

8

Inspect the transmission for the correct fluid type. Refer to Transmission Fluid Replacement .

Is the transmission fluid the correct type?

Go to Step 10

Go to Step 9

9

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

Did you find and repair the condition?

Go to Step 23

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 Control Lever and/or Boot Replacement .

Did you find and repair the condition?

Go to Step 23

Go to Step 12

12

Is the vehicle equipped with a power take off (PTO)?

Go to Step 13

Go to Step 16

13

Remove the PTO, in order to confirm that the PTO is not the cause of the noise.

Is the noise still present?

Go to Step 16

Go to Step 14

14

Inspect the countershaft gear for damage from the PTO.

Is the countershaft gear damaged?

Go to Step 22

Go to Step 15

15

Reinstall the PTO. Ensure it is properly shimmed. Refer to the PTO manufactures installation procedure.

Is the noise still present?

Go to Step 16

Go to Step 23

16

Is the vehicle equipped with a transfer case?

Go to Step 17

Go to Step 18

17

Engage the transfer case in the different modes.

Is the noise still present or the same?

Go to Step 18

Go to Symptoms - Transfer Case for the NVG 149, Symptoms - Transfer Case for the NVG 246, Symptoms - Transfer Case for the NVG 261-NP2, or Symptoms - Transfer Case for the NVG 263-NP1

18
  1. Inspect for engine to transmission alignment.
  2. Inspect for loose transmission mounting bolts.

Are there any loose transmission mounting bolts?

Go to Step 19

Go to Step 20

19

Replace and tighten the transmission mounting bolts. Refer to Transmission Rear Mount Replacement .

Is the noise still present?

Go to Step 20

Go to Step 23

20

With the engine operating, depress the clutch pedal.

Is the noise still present?

Go to Step 21

Go to Step 22

21
  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 pressure plate
    • The clutch disc
    • The input shaft bearing
    • The engine crankshaft end play

Did you find and repair the condition?

Go to Step 23

Go to Step 22

22

  1. Remove the transmission. Refer to Transmission Replacement .
  2. Disassemble the transmission. Refer to 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 23

--

23

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 1