A whining noise from the rear of your car most often comes from the rear differential. Its gear oil may be low or worn out, or the gears and bearings inside may be wearing.
Here are the usual causes:
- Gear oil: Low or dirty oil can make the gears whine or howl.
- Gears and bearings: Worn parts can whine or growl, often louder with speed.
- Wheel bearings: A worn one can make a high-pitched noise that rises as you speed up.
- Tires: Cupped tires can sound like a bad differential.
Notice when you hear it. A US parts guide says a worn pinion bearing often whines differently on the gas than off it.
Don’t put it off. Caught early, a drain and refill with fresh fluid may quiet a mild whine. Left alone, low oil can let the gears and bearings overheat and fail. Stop driving and call for help if the noise turns to grinding or clunking, or gets louder fast.
Have our mechanics check it soon. For prices, read our guide to differential fluid change cost in Vancouver.
Service desk The full guide
Differential fluid change cost in Vancouver: the published prices, what a quote covers and how to compare quotes.