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Home >> Cadillac >> 2021 >> CT4 Sport, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 117 (Manual Transmission - TREMEC 6-Speed (Mg9) - Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> Transmission Noisy >> Test Description

Test Description

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

  1. 5 

    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. 7 

    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. 9 

    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. 13 

    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. Transmission Fluid Drain and Fill
Did you find and repair the condition?
Go to Step 16  Go to Step 7 
7  Inspect the transmission for the correct fluid type. Approximate Fluid Capacities
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. Transmission Fluid Drain and Fill
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. Manual 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. Fastener 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. Clutch Assembly Replacement
  2. Inspect the following components for being the cause of the noise:
    • 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. Manual Transmission Removal and Installation
  2. Disassemble the transmission. Use the information in the Cleaning and Inspection section to determine if any of the transmission components are faulty. Transmission Disassemble
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