M5 Expert (>4000)
Join Date: Feb 2001
Location: west palm beach. fl.
Thanked 1,420 Times in 1,038 Posts
I'd get it into a shop that knows what to look for. It could be any of the things mentioned but if it is the pinion bearing or anything else in the diff, you want to fix that immediately. The pinion bearing in mine went out but wasn't making significant noise. Eventually it broke teeth under load and the differnetial had to be replaced. That is not a cheap experience.
Used diffs show up from time to time on ebay and other sites. Price around $750-$1000 or so these days. Of course, there is never one around when yours breaks and you need it right away.........
Dinan Stage 3 suspension, SS jet coated headers, ESS SC kit w/ 1 range colder NGK's, 92mm pulley, 440 Big Greens, TTFS alpha N tune, RK plenum plates, CNS 10.5 dual mass clutch, open brake ducts, Hamann front splitters, TEC cupholder, U.S.(Euro style) tilt/slide armrest, 6k HID fogs, 6k super white low beams, V1/Stealth1, dual head LI, 2.65 diff w/40% lockup/2x dynamic, compact spare, Euro trailer hitch, Mocal oil cooler, ACS type rear spoiler, Rogue custom SSK and tranny mounts, ST 355 BBK (fronts), BP sway bar brackets, Bluetooth retrofit, Speedhut boost gauge, Dinan TB's and VS, KB BAP, Howerton/HFS-3 Aquamist WI trunk setup.......