E90 rear-diff seeping?

voltron1011 · 06-14-2007, 05:04 PM

Since I'm new to BMW, is it normal for the rear-end (rear diff case) to seep a little around the input and output shafts? I noticed it a couple of months ago when I was poking around under the car. It's not leaking heavily and you can really only notice it because dust is starting to collect around it.
I just went in for my 30000 mile inspection and they didn't seem to mention it.

Fleet, maybe you could provide some insite on this?

ENINTY · 06-16-2007, 07:39 AM

It's not abnormal. Some do, some don't. It would only drip if the rear cover gasket is bad (rare in a BMW diff) Dust means you have very light seepage when the diff lube is under pressure (i.e. driving). If you start getting oil on the chassis or rear subframe then you may want BMW to replace the seals. With what you have, you run the risk of replacing the seal and actually end up with more leakage if the seal is not installed correctly.

voltron1011 · 06-16-2007, 01:10 PM

Thanks Entity, I was thinking it wasn't serious but I haven't owned a rear-wheel drive car in so many years that I can't remember what's considered normal.

06-14-2007, 05:04 PM	#1
voltron1011 Colonel 119 Rep 2,909 Posts Drives: 2011 135i, FJR-1300 Join Date: Apr 2005 Location: Wiesbaden iTrader: (2)	E90 rear-diff seeping? Since I'm new to BMW, is it normal for the rear-end (rear diff case) to seep a little around the input and output shafts? I noticed it a couple of months ago when I was poking around under the car. It's not leaking heavily and you can really only notice it because dust is starting to collect around it. I just went in for my 30000 mile inspection and they didn't seem to mention it. Fleet, maybe you could provide some insite on this?
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06-16-2007, 07:39 AM	#2
ENINTY Banned 173 Rep 3,415 Posts Drives: 2006 325i Sport Join Date: Jun 2006 Location: Virginia iTrader: (0)	It's not abnormal. Some do, some don't. It would only drip if the rear cover gasket is bad (rare in a BMW diff) Dust means you have very light seepage when the diff lube is under pressure (i.e. driving). If you start getting oil on the chassis or rear subframe then you may want BMW to replace the seals. With what you have, you run the risk of replacing the seal and actually end up with more leakage if the seal is not installed correctly.
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06-16-2007, 01:10 PM	#3
voltron1011 Colonel 119 Rep 2,909 Posts Drives: 2011 135i, FJR-1300 Join Date: Apr 2005 Location: Wiesbaden iTrader: (2)	Thanks Entity, I was thinking it wasn't serious but I haven't owned a rear-wheel drive car in so many years that I can't remember what's considered normal.
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