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27rotax
09-16-2005, 03:44 PM
Hi all... I recently purchased an '01 m3 with 62k miles and have been having a blast with it ever since, but I'm trying to sort out a few things. I saw another thread mentioning a rear end clunk and am looking for a bit more info on it. My car seems to have a lot of slack in the final drive and will clunk pretty loudly, coming on and off the clutch, and on and of the gas, if driving at a steady speed in gear. The local dealer (which I don't trust on bit!) say the noise is normal. It feels like a worn differential to me. Any thoughts?
As well, the tranny seems pretty balky and will grind a little if shifted too quickly in the lower gears. I'm about to change the oil to the LT-2 and see if that helps, but I believe the oil was changed about 20k miles ago (to lt-2) by the previous owner. Suggestions?
I'm sure the car was driven hard for it's miles, and I intend to do the same, but it's still under CPO warranty, so I want to get things sorted out while I can. Thanks for any help you can offer!

GregW in Oregon
09-16-2005, 10:03 PM
Hi all... I recently purchased an '01 m3 with 62k miles and have been having a blast with it ever since, but I'm trying to sort out a few things. I saw another thread mentioning a rear end clunk and am looking for a bit more info on it. My car seems to have a lot of slack in the final drive and will clunk pretty loudly, coming on and off the clutch, and on and of the gas, if driving at a steady speed in gear. The local dealer (which I don't trust on bit!) say the noise is normal. It feels like a worn differential to me. Any thoughts?
As well, the tranny seems pretty balky and will grind a little if shifted too quickly in the lower gears. I'm about to change the oil to the LT-2 and see if that helps, but I believe the oil was changed about 20k miles ago (to lt-2) by the previous owner. Suggestions?
I'm sure the car was driven hard for it's miles, and I intend to do the same, but it's still under CPO warranty, so I want to get things sorted out while I can. Thanks for any help you can offer!
The "clunk" is totally normal. New ones do it (go test drive). The explanation from BMW has to do with the special design of the M Lock diff. With practice you will learn to minimize it.

There may be some synchro wear if you have grinding. The tranny is naturally a little notchy. A short shift kit can help. I have the ACS one, but Autosolutions is highly regarded. I hve not experimented with aftermarket oil.

Pinecone
09-17-2005, 05:52 AM
For short ****ers, Rogue or UUC are more normally recommended.

Going to the new BMW LTF2 tranny fluid does help. Aftermarket fluids may cause you problems with warranty if you actually have a serious tranny problems. But people have reported good results with Royal Purple SynchroMax lube.

27rotax
09-17-2005, 10:36 AM
Thanks for your help guys. The other BMW's I've had didn't have anywhere near the power this car does, so I'm not sure which noises are normal, or if the diff. is about to strip itself!
Any thought's on bumping up the front tire width? I'd like to stick with 255's in the rear, but am planning on a new set of summer wheel's (bbs ch's). Would a 18x9? wheel work with 255's in the front as well? I haven't autocrossed the car yet, but I can already feel the understeer....

GregW in Oregon
09-17-2005, 12:16 PM
Thanks for your help guys. The other BMW's I've had didn't have anywhere near the power this car does, so I'm not sure which noises are normal, or if the diff. is about to strip itself!
Any thought's on bumping up the front tire width? I'd like to stick with 255's in the rear, but am planning on a new set of summer wheel's (bbs ch's). Would a 18x9? wheel work with 255's in the front as well? I haven't autocrossed the car yet, but I can already feel the understeer....
You can run a square setup of 255s, or 265s (265/35-18) with the right offset.

Pinecone
09-24-2005, 02:25 PM
Quick, easy, and reasonably cheap. Get 2 more rear wheels, put 265/35-18s on all four, bolt them on. Yes, they do fit. Not with the 19s though.

You will need a bit of negative camber to make it look really nice thoguh, pull the pins and swap the hats. I get about 2.7 degrees negative, and the car looks MEAN, and handles extremely well.