Noise
Important: Do not confuse this noise with pump whine noise, which is usually noticeable in PARK, NEUTRAL and all other gear ranges. Pump whine will vary with line pressure.
You may notice a torque converter whine when the vehicle is stopped and the transmission is in DRIVE or REVERSE. This noise will increase as you increase the engine RPM. The noise will stop when the vehicle is moving or when you apply the torque converter clutch, because both halves of the converter are turning at the same speed.
Perform a stall test to make sure the noise is actually coming from the converter
- Place your foot on the brake.
- Put the gear selector in DRIVE. NOTE: You may damage the transmission if you depress the accelerator for more than 6 seconds.
- Depress the accelerator to approximately 1,200 RPM for no more than six seconds.
A torque converter noise will increase under this load.
Isolating Vibration
Note. Some engine/transaxle combinations cannot be balanced in this manner due to limited clearances between the torque converter bolts and the engine. Ensure that the bolts do not bottom out in the lug nuts or the torque converter cover could be dented and cause internal damage.
To isolate and correct a flywheel or torque converter vibration, separate the torque converter from the flywheel to determine if vibration is in the engine or transmission.
- With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration.
- Turn the engine OFF.
- Raise and suitably support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-188480-S19457848752005090300000) in General Information.
- Remove the transmission converter cover bolts and the cover.
- Mark the relationship of the converter to the flywheel.
- Remove the bolts attaching the converter to the flywheel.
- Slide the torque converter away from the flywheel.
- Rotate the flywheel and torque converter to inspect for defects or missing balance weights. Refer to «ENGINE FLYWHEEL CLEANING AND INSPECTION»(ref-188499-S01227614532005090700000) in Engine Mechanical - 4.2L or «ENGINE FLYWHEEL CLEANING AND INSPECTION»(ref-188498-S19289295952005090700000) in Engine Mechanical - 5.3L.
- Lower the vehicle.
- With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration. Refer to «DIAGNOSTIC STARTING POINT - VIBRATION DIAGNOSIS AND CORRECTION»(ref-188481-S07024419342005090300000) in Vibration Diagnosis and Correction.
- Turn the engine OFF.
Noise and Vibration Analysis
A noise or vibration that is noticeable when the vehicle is in motion MAY NOT be the result of the transmission.
If noise or vibration is noticeable in PARK and NEUTRAL with the engine at idle, but is less noticeable as RPM increases, the cause may be from poor engine performance.
- Inspect the tire for the following: Uneven wear Imbalance Mixed sizes Mixed radial and bias ply
- Inspect the suspension components for the following: Alignment and wear Loose fasteners
- Inspect the engine and transmission mounts for damage and loose bolts.
- Inspect the transmission case mounting holes for the following: Missing bolts, nuts, and studs Stripped threads Cracks
- Inspect the flywheel for the following: Missing or loose bolts Cracks Imbalance
- Inspect the torque converter for the following: Missing or loose bolts or lugs Missing or loose balance weights Imbalance
Noise Conditions
Drive Link Noise: A whine or growl that increases or fades with vehicle speed, and is most noticeable under a light throttle acceleration. It may also be noticeable in PARK or NEUTRAL operating ranges with the vehicle stationary.
Final Drive Noise: A hum related to vehicle speed which is most noticeable under a light throttle acceleration.
Planetary Gear Noise: A whine related to vehicle speed, which is most noticeable in FIRST gear, SECOND gear, FOURTH gear or REVERSE. The condition may become less noticeable, or go away, after an upshift.
Pump Noise: A high pitched whine that increases in intensity with engine RPM. This condition may also be noticeable in all operating ranges with the vehicle stationary or moving.
Torque Converter Noise: A whine usually noticed when a vehicle is stopped, and the transmission is in DRIVE or REVERSE. The noise will increase with engine RPM.