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2003 BMW 3-Series 325Ci 2dr Coupe

2003 BMW 3-Series
Trim Info:
Rear Wheel Drive, 2 Door Coupe, Sub-Compact
20 mpg city / 29 mpg hwy
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November 29, 2012, 5:08 am

Demetris D

Question: Rear Differential trouble

I have a very big whine which has been going on for about 3 months now. My car has lost a lot of power etc. I am currently driving an e93 convertible petrol m sport 320i. The ratio for the diff I need is 3.64, but costs about 1000 quid more than other ones around that range like 3.56, 3.23 and so on. Would these be compatible, would they work or would they end up screwing up my car for good?

December 1, 2012, 11:07 am

Ron W
Expert Mechanic

You'll have to check with BMW about ratio changes.

Mechanically they probably would work, but electronically the computer is programmed with the original ratio so you may have unknown issues if you change the ratio.

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