Bearing Whine

Bearing Whine
Bearing whine is a high-pitched sound similar to a whistle. It is usually caused by worn/damaged pinion bearings. Bearing noise occurs at all driving speeds. This distinguishes it from gear whine which is speed dependent.

As noted, pinion bearings make a high-pitched, whistling noise, usually at all speeds. If however there is only one pinion bearing that is worn/damaged, the noise may vary in different driving phases.

A wheel bearing noise can be mistaken for a pinion bearing noise.