|NOTICE No: MT000000981
|MODEL: Mazda MPV
|AFFECTED VINs: N/A
|SUBJECT: Tire And Driveline Noise/Vibration Diagnosis
|APPLICABLE MODELS: 99-01 Protege, 98-01 626, 00-01 MPV, 99-01 Miata, 95-01 Millenia|
The following are some general hints (for all models) for diagnosing the cause of various driveline noises:
- Make sure road surface does not cause the noise/vibration by testing on various road surfaces (normally there is no difference in the noise if it is road surface noise during accel/coast/float driving
- Check that the noise is not inherent tire noise/vibration: TEMPORARILY inflating tires to the tire's maximum PSI will usually significantly alter tire noise, but will have no effect on trans./dif. noise.
- If not road or tire noise, determine what RPM/Speed the noise is most pronounced, then stop the vehicle in a quiet place. With trans. in neutral, run the engine through the corresponding RPMs. If subject noise is heard, it is coming from the engine or trans.
- Wheel Bearings: While holding the vehicle at a steady speed where the noise is heard, lightly apply the brakes (vary service brake and rear E-brake as needed). This will often decrease any bearing noise as
some of the load is take off the bearings when the brakes are applied. Also check wheel hub temperatures. If one wheel has higher temperature, the bearing is suspect.
If the above does not reveal the cause, note the following:
- Faulty differential gears normally produce noise in a very limited speed/rotation range, and differs with accel/coast/decel conditions.
- Faulty drive axle bearings usually vary in pitch with road speed or transmission shaft speed.
As always, if the above hints do not determine the cause, substitute known good components ONE AT A TIME (ie: tires, wheels, dif, trans, driveshaft, etc.) to determine the cause. Consult with TSD powertrain specialists before proceeding with parts replacements.
- CONSUMER NOTICE:
- The information and instructions in this notice are intended for
use by skilled technicians. Mazda technicians utilize the proper
tools/equipment and take training to correctly and safely maintain
Mazda vehicles. These instructions should not be performed by
"do-it-yourselfers." Consumers should not assume this
notice applies to their vehicle or that their vehicle will develop
the described concern. To determine if the information applies,
consumers should contact their nearest authorized Mazda dealership.