For 1990-2009 cars

### 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 vibration occurs at a certain road speed , or carrying a certain load, the driveline axle may not be correct, and possibly causing a vibration. The vibration may be resonating into the transmission causing a noise.

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 transmission noise entering the driver compartment. If the shift boot or other cab components are not sealed properly the transmission may seem noisier due to the noise entering through an unsealed component.

4. 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. If the transmission is equipped with an air shift control, refer to the transmission manufacturer repair manual for the correct diagnosis and repair.
1 | Did you review the manual transmission symptom operations 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 in Vibration Diagnosis and Correction. Did you find and repair the condition? | Go to Step 19 | 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 18 | Go to Step 6
6 | Inspect the transmission fluid for the correct type and level. Refer to Transmission Fluid Check . Is the fluid type and level correct? | Go to Step 8 | Go to Step 7
7 | Add transmission fluid. Refer to Transmission Fluid Check . Did you find and repair the condition? | Go to Step 19 | Go to Step 8
8 | Inspect the shift boot for proper installation. Refer to Control Lever and/or Boot Replacement . Did you find and repair the condition? | Go to Step 10 | Go to Step 9
9 | Inspect the driver compartment for areas where transmission noise may enter. Did you find and repair the condition? | Go to Step 19 | Go to Step 10
10 | Is the vehicle equipped with a power take off (PTO)? | Go to Step 11 | Go to Step 14
11 | Remove the PTO, in order to confirm that the PTO is not causing the noise. Is the noise still present? | Go to Step 14 | Go to Step 12
12 | Inspect the countershaft gear for damage from the PTO. Is the countershaft gear damaged? | Go to Step 18 | Go to Step 13
13 | Reinstall the PTO and ensure it is properly shimmed. Refer to the PTO manufactures installation procedure. Is the noise still present? | Go to Step 14 | Go to Step 19
14 | Inspect for engine to transmission alignment and loose transmission mounting bolts. Refer to Transmission Mount/Support Replacement . Are there any loose transmission mounting bolts? | Go to Step 15 | Go to Step 16
15 | Replace and tighten the transmission mounting bolts. Refer to Fastener Tightening Specifications . Is the noise still present? | Go to Step 16 | Go to Step 19
16 | With the engine operating, depress the clutch pedal. Is the noise still present? | Go to Step 17 | Go to Step 18
17 |

1. Remove the clutch. Refer to Clutch Assembly Replacement in Clutch.
2. Inspect the following components for being the cause of the noise.

• | The release bearing

• | The clutch brake, if equipped

• | 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 19

Go to Step 18

18 |

1. Remove the transmission. Refer to Transmission Replacement .
2. Disassemble the transmission. Refer to the transmission manufacturer repair manual to determine if any of the transmission components are faulty.

Did you find and repair the condition?

Go to Step 19

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19 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 1