If the transmission is in neutral with the engine operating, and a whirling noise - neutral gear rattle - is heard outside the vehicle, this is a normal condition.
The numbers below refer to the step numbers on the diagnostic table.
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 causing a vibration. The vibration may be resonating into the transmission causing a noise.
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.
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 condition. Overheating may cause damage to the transmission components.
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.
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 | ||||||||||||||
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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 | |||||||||||||||
2 | Is the noise present while in neutral, with the engine operating? | Go to Diagnostic Aids | Go to Step 3 | ||||||||||||||
Is the noise present at a certain road speed or with a certain load? | Go to Step 4 | Go to Step 5 | |||||||||||||||
4 | Inspect for the correct driveline angle. Refer to Vibration Analysis - Driveline in Vibration Diagnosis and Correction. Did you find and repair the condition? | Go to Step 22 | Go to Step 5 | ||||||||||||||
5 | Is the noise present in all gears? | Go to Step 7 | Go to Step 6 | ||||||||||||||
6 | Is the noise present in just one gear? | Go to Step 21 | Go to Step 7 | ||||||||||||||
Inspect the transmission fluid level. Is the fluid level correct? | Go to Step 9 | Go to Step 8 | |||||||||||||||
8 | Add transmission fluid. Refer to Transmission Fluid Replacement . Did you find and repair the condition? | Go to Step 22 | Go to Step 9 | ||||||||||||||
Inspect the transmission for the correct fluid type. Refer to Lubrication Specifications . Is the transmission fluid the correct type? | Go to Step 11 | Go to Step 10 | |||||||||||||||
10 | 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 22 | Go to Step 11 | ||||||||||||||
Inspect the shift tower boot. Is the closeout boot loose or damaged? | Go to Step 12 | Go to Step 13 | |||||||||||||||
12 | 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 22 | Go to Step 13 | ||||||||||||||
13 | Is the vehicle equipped with a power take off (PTO)? | Go to Step 14 | Go to Step 17 | ||||||||||||||
14 | Remove the PTO, in order to confirm that the PTO is not causing the noise. Is the noise still present? | Go to Step 17 | Go to Step 15 | ||||||||||||||
15 | Inspect the countershaft gear for damage from the PTO. Is the countershaft gear damaged? | Go to Step 20 | Go to Step 16 | ||||||||||||||
16 | Install the PTO and ensure it is properly shimmed. Refer to the PTO manufactures installation procedure. Is the noise still present? | Go to Step 17 | Go to Step 20 | ||||||||||||||
17 | Inspect for engine to transmission alignment and loose transmission mounting bolts. Are there any loose transmission mounting bolts? | Go to Step 18 | Go to Step 21 | ||||||||||||||
18 |
Notice: Refer to Fastener Notice in the Preface section. Replace and tighten the transmission mounting bolts. Refer to Fastener Tightening Specifications . Is the noise still present? | Go to Step 19 | Go to Step 22 | ||||||||||||||
With the engine operating, depress the clutch pedal. Is the noise still present? | Go to Step 20 | Go to Step 21 | |||||||||||||||
20 |
Did you find and repair the condition? | Go to Step 22 | Go to Step 21 | ||||||||||||||
21 |
Did you find and repair the condition? | Go to Step 22 | -- | ||||||||||||||
22 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 1 |