[Chubbs]

I have a 1998 323i coupe which has for some time been making a whirring noise which increases when I speed up and decreases when i slow down. This has recently got much noisier and is sometimes accompanied by a rattle. I am told it is a noisy diff and it is a common problem. If its that common I wondered if anyone else had encountered it? Ideally I would replace it with a reconditioned part but as this is likely to have come from a car even older than mine is it likely to just happen again?? Any help appreciated.

 

[DSK]

To be honest, the diffs are pretty solid units on these cars. I'd personally change the gearbox & diff oil (using the correct specification oil as stated in your onwers hand book). This should make a significant improvement provided your diff is not shot. (Use of incorrect specification fluids in the gearbox & diff will only do harm).

Fwiw, I change my g/box & diff oil at each service. Even from cold the units are sublime and silent. Done this on all my cars over the years I've been driving and never had any issues with the odd whine or slightly stiff drivetrain whilst cold.

 

[328mark]

any particular reason you have discounted the wheel bearing(s)?

 

[hamish262001]

any particular reason you have discounted the wheel bearing(s)?

yep far more common for bearings than the diff

 

[steve_nurburgring]

doubt its your diff mate, like the other post these diffs are strong. had bm's for years and never known one go. wheel bearings ?