these rear gear units usually work or dont work, the clearances impressed me when I checked them before swaping out bearings and stuff. the most likely time anything will go wrong is when someone swaps out the pinion flange... find my write up on this.
The auto trans with overdrive makes little difference on the highway mileage, mine revs a little higher but the mileage is no different. The city mileage is actually a little better, probably from less gas peddle getting the car moving.
95 E34 530I V2.37
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