Non-Axle Noise

The five most common sources of non-axle noise are exhaust, tires, roof racks and trim mouldings and transaxle.

Therefore, make sure that none of the following conditions are the cause of the noise before proceeding with a driveline teardown and diagnosis.
- In certain conditions, the pitch of the exhaust may sound very much like gear noise. At other times, it can be mistaken for a wheel bearing rumble.
- Tires, especially snow tires, can have a high pitched tread whine or roar, similar to gear noise. Radial tires, to some degree, have this characteristic. Also, any non-standard tire with an unusual tread construction may emit a roar or whine-type noise.
- Trim and mouldings can also cause whistling or whining noise.
- Clunk may be a metallic noise heard when the automatic transaxle is engaged in REVERSE or DRIVE, or it may occur when throttle is applied or released. It is caused by backlash somewhere in the driveline.
- Bearing rumble sounds like marbles being tumbled. This condition is usually caused by a malfunctioning wheel bearing.

Noise Conditions
- Gear noise is typically a howling or whining due to gear damage or incorrect bearing preload. It can occur at various speeds and driving conditions, or it can be continuous.
- Chuckle is a particular rattling noise that sounds like a stick against the spokes of a spinning bicycle wheel. It occurs while decelerating from 64 km/h (40 mph) and can usually be heard all the way to a stop. The frequency varies with vehicle speed.
- Knock is very similar to chuckle, through it may be louder and occurs on acceleration or deceleration. The teardown will disclose what has to be corrected.

Check and rule out tires, exhaust and trim items before disassembling the transaxle to diagnose and correct gear noise.

The noises described under Road Test usually have specific causes that can be diagnosed by observation as the unit is disassembled. The initial clues are the type of noise heard on the road test and the driving conditions.