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.
- Depress the accelerator to approximately 1,200 RPM for no more than 6 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 restricted access or 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 which could dent 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-241684-S36257494482006081100000) in General Information.
- Remove the transmission converter cover bolts and the cover. Refer to «Torque Converter Cover Replacement»(ref-241713-S24745979452006081100000) .
- Mark the relationship of the converter to the flywheel.
- Remove the bolts attaching the converter to the flywheel. Refer to «Flywheel to Torque Converter Bolt Replacement»(ref-241713-S03548337862006081100000) .
- 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-241709-S21732576152006081100000) in Engine Mechanical - 3.5L.
- Lower the vehicle.
- With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration. See appropriate Vibration Analysis Engine article.
- 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.
- Vibration may also be caused by a small amount of water inside the converter.
- Inspect the tires for the following conditions: Uneven wear Imbalance Mixed sizes Mixed radial and bias ply
- Inspect the suspension components for the following conditions: Alignment, wear or damage Loose fasteners Driveline damage or wear
- Inspect the engine and transmission mounts for damage and loose bolts.
- Inspect the transmission case mounting holes for the following conditions: Missing bolts, nuts and studs Stripped threads Cracks
- Inspect the flywheel for the following conditions: Missing or loose bolts Cracks Imbalance
- Inspect the torque converter for the following conditions: Missing or loose bolts or lugs Missing or loose balance weights Imbalance caused by heat distortion or fluid contamination
Popping Noise
| Checks | Action |
|---|---|
| DEFINITION: A popping noise, similar to popcorn popping | |
| Oil Pump System | Check fluid level. Inspect for pump cavitation, indicated by bubbles in fluid. Inspect the transmission fluid filter for a leaky seam. Inspect the transmission fluid filter seal for improper positioning or for a cut seal. |
Popping Noise
Buzz Noise or High Frequency Rattle Sound
| Checks | Action |
|---|---|
| DEFINITION: A buzz or high frequency rattle | |
| Trace Cooler Pipes Check for binding or contact at the Radiator, other than at the Cooler Pipe connectors | Verify a pressure buzz by watching for a needle vibration of the pressure gage. A road test may be necessary. Refer to Road Test Procedure . |
Buzz Noise or High Frequency Rattle Sound
Whine/Growl Noise That Changes with Vehicle Speed
| Checks | Action |
|---|---|
| DEFINITION: A whine or growl that increases and fades with vehicle speed and is most noticeable under light acceleration | |
| Drive Link Assembly System | Verify that the noise comes from the sprockets or the from the drive link assembly chain by placing your left foot on the brake and by moving the gear selector from Park or Reverse. If the noise stops, check the following items. |
| Drive Sprocket Support (522) and Driven Sprocket Support (609) | The bearing outer race support is rough or nicked. |
| Drive Sprocket (516) and Driven Sprocket (506) | Broken or sheared teeth Nicked or scored bearing surfaces The bearing race or roller bearing surfaces on the gear support inner bearing are rough or pitted A damaged bearing |
| Drive Chain (507) | Stretched |
Whine/Growl Noise That Changes with Vehicle Speed
Final Drive Noise or Hum Noise
| Checks | Cause |
|---|---|
| DEFINITION: A final drive noise or hum is most noticeable under light throttle acceleration or turns | |
| Final Drive Gear Set (700) Final Drive Internal Gear (693) | Worn planet pinions Worn washers Worn or damaged teeth |
| Differential Carrier (700) Differential Side Gears (705) | Worn or pitted gears A damaged thrust washer |
Final Drive Noise or Hum Noise
Noise in First, Second, Third or Fourth
| Checks | Cause |
|---|---|
| Final Drive Sun Gear (697) Final Drive Pinions (711) | Worn or damaged gears |
Noise in First, Second, Third or Fourth
Noise in Random Ranges
| Checks | Action |
|---|---|
| DEFINITION: Noise only in certain gear ranges | |
| Refer to Range Reference . Determine the power flow and the applicable components that may be causing this noise. | |
Noise in Random Ranges
Abnormal Noise in Park or Neutral Range
| Checks | Cause |
|---|---|
| DEFINITION: Noise only in Park or Neutral | |
| Drive Sprocket Support (522) and Driven Sprocket Support (609) | Nicked or scored bearing surfaces The bearing race or roller bearing on the gear support inner bearing are rough or pitted. The bearing outer race support is rough or nicked. A damaged bearing |
| Forth Clutch Assembly | Clutch plates (501) damaged or worn |
Abnormal Noise in Park or Neutral Range