In Reply to: 735iL Drive Shaft Scraping posted by Paul Gajda on April 08, 2001 at 14:14:15:
I have a 1991 735iL. I experiece a fairly loud scraping that sounds like the drive shaft is scraping the heat shields under the following conditions. 1. Drive at highway speeds for several miles. 2. Come to a stop light and site for more than 45 seconds. 3. Drive away and there is a loud scraping coming from about end of the transmission area. When I turn right the scraping is pronounces. When I turn left the scraping subsides. After driving for about 60 secons the scraping goes away. The last time the car was in the shop the mechanic replaced the transmission mounts. That did not do the trick. I live in Florida and do not encounter this problem during the cool winter months.
Paul, I had the exact same problem... thought it was related to heat shields on catalytic converter warping "just enough" to hit the driveshaft. Anyhoo, it turned out to be a seizing u-joint. WHen heated up (run on the highway), it would get stiff... then when sitting still, it would take a "set". Driving off would force it to turn, but it didn't WANT to turn... resulting in deflection about the center bearing.
Fix was straightforward, get a remanufactured driveshaft, there are a few advertisers in thr ROUNDEL. While mine was out, I had the mechanic check my clutch, which was a convenient time to replace it... as well as transmission mounts, rear engine seal, and transmission seals, none of which were leaking badly enough to require going after, but since it was apart anyway, what the hell. Car has 185K miles, and owes me nothing.
Driveshaft for my car (E32 5sp) was kind of rare, so I had to have MY driveshaft sent out and reworked... otherwise, most places have 'em in stock, and will charge a core fee. Mine came to $600 parts, plus clutch parts, seals, transmission mounts, etc.
'88 735i 5sp