Greetings all,

 

My wife's 1997 Impreza 2.0 Sport has developed a nasty noise, which I suspect is the rear diff but I'm not sure. The noise started a month or so ago and has got noticeably worse since. It is a moaning/whining, a bit like an old bus with a knackered gear box. It sounds like it is coming from under the rear end of the car. The volume of the noise increases with road speed; it becomes noticeable at about 15mph and gets louder until around 45mph when it's really very loud, the noise then stays about the same volume at higher speeds. Lifting off the throttle, dipping the clutch or putting the car in neutral makes no difference -the noise changes only with road speed, not engine speed. I would suspect a wheel bearing but going straight ahead or turning makes no difference to the noise.

 

When I get two minutes I will change the rear diff oil but I wonder if the diff is broken, or if it's something else. Any thoughts please?

 

thanks,

Tim

Diff noise is normally louder when under load (accelerating/decelerating)

if a wheel bearing is completely knackered it will make a noise in a straight line. so that would be the first I'd say to investigate further .

Try cornering with the clutch dipped to see if you can hear if one side is noisier .

Jack the back end up , take the handbrake off and check for top to bottom or side to side play .

It could still be diff so maybe check the oil levels while it's up in the air as well .

Best of luck and hopefully it will be a cheap fix

From what you saying I would say wheel bearing. Back when my dad had ford focus diesel it had exactly same problem as you have, and it did turn out to be a wheel bearing.