Anyone encountered a humming noise from there diff?

**Raff** · 07-21-2005, 03:10 AM

I recently swap my 325i diff for a 325is diff. The old one had some humming noise, but the 325is diff makes a bit more of a humming noise. Anyone have encountered this before.

Thanks,

**uberpanzer** · 07-21-2005, 04:11 AM

...you sure the LSD has the right additive in it? They need a certain TYPE of gear oil and that can be addressed with the additive.

**Raff** · 07-21-2005, 04:32 AM

They put oil in it, but in don't know what kind. Is there a certain kind of oil and how do I check it?

Thanks for the reply uberpanzer

**cgregory** · 07-21-2005, 08:09 AM

I'd just drain it and put some Redline 75w90 in it...there's no way of knowing when the last time the fluid was changed out and it's good to be on the safe side.

**2002maniac** · 07-21-2005, 08:30 AM

The input bearing (i think) is shot on my diff. I have tried several kinds of oils and addatives to no avail. It humms and whines like crazy, it is almost unbearable at freeway speeds. Im just turning the radio up til my new diff comes in.

**bkcraun** · 07-21-2005, 08:48 AM

Are you sure it is diff noise and not a wheel bearing?

**Raff** · 07-21-2005, 12:03 PM

Originally Posted by cgregory

I'd just drain it and put some Redline 75w90 in it...there's no way of knowing when the last time the fluid was changed out and it's good to be on the safe side.

Really, I will try that. Its it pretty easy to do that. Is it some thing I can do at home with floor jacks and basic tools?

Thanks,

**Raff** · 07-21-2005, 12:06 PM

Originally Posted by 2002maniac

The input bearing (i think) is shot on my diff. I have tried several kinds of oils and addatives to no avail. It humms and whines like crazy, it is almost unbearable at freeway speeds. Im just turning the radio up til my new diff comes in.

2002maniac,

Did you swap to a different diff? How long have you had this problem? Is that bad for the car?

Thanks for your input

**Raff** · 07-21-2005, 12:07 PM

Originally Posted by bkcraun

Are you sure it is diff noise and not a wheel bearing?

Sure its not the brearing, since they have been changed also.

**cgregory** · 07-21-2005, 01:14 PM

Originally Posted by Raff

Really, I will try that. Its it pretty easy to do that. Is it some thing I can do at home with floor jacks and basic tools?

Thanks,

Very easy to do...just jack the car up, drain the fluid. Get a fluid pump (the only thing you might not have) and pump the new fluid into the inlet. It'll probably take 15-20 mins and will cost you $10 (or $20 if you need to buy the fluid pump).