Severe driveline shake above 30-35mph, rebuilt driveshaft didn't help

[Vincent Brick]

After not being driven all last weekend while I tried to fix more stuff, my car suddenly had a violent shake preventing me from going above 35 mph or so. Everything indicated it was the driveshaft, and the slip coupling was loose, so I had a reputable place that rebuilds BMW driveshafts give mine the full treatment at a cost of over $300. After 2 more days of not being able to drive the car I get the new driveshaft back in, and its immediately shaking again, just not as bad. I have my roommate drive it, who is a mechanic at an independent BMW repair/race shop, and the shake is immediately gone. Try to drive it to work today, shake is back. I have him drive it again, its not as bad and he tells me it should get me to work (35 miles away) which it does. Then I try to drive home, and the shake is back full bore, to the point I can't even take it above 35 mph, it feels like the whole car is gonna shake apart. Now I am left without a way to work AGAIN, despite that fact that I have spent far more money on it in the 6 months I've owned it than it will ever be worth.

Can anyone provide me with any insight as to what could be wrong? We're gonna take it apart at my work tomorrow after I get off (fortunately my work has a shop), everything in the Bentley manual points to driveshaft, but the driveshaft place is closed through the weekend so I'm left without wheels again. Could I have fucked anything up? Its not my first time doing this, I did a CSB and slip joint in a friend's E36 years ago and everything went smoothly.

I tried rotating the tires to make sure it wasn't some sort of wheel balance issue, no change. Driveshaft and halfshafts are all solid when I try to shake them, no abnormal play. my dif is on the way out too, but there is no chance


Thanks.

[Delta]

When I replaced my driveshaft with a rebuilt unit (from a reputable shop that does bmw shafts out of Texas and California) the first one vibrated worse than my original shaft with a seized rear joint. The second driveshaft wasn't phased correctly, which could be the problem here.

After a lot of calling them and explaining the situation, they rebuilt my original driveshaft and it's been good since.

Things to check:

U-joints properly phased
Center bearing good and installed the correct direction ( and also preloaded when bolted down)
Good guibo
Good trans and motor mounts

[Vincent Brick]

I don't know anything about U joints or the phasing of them, can you recommend any articles or resources I can read on it before I go on a random google hunt?

Center bearing is brand new as of 2 days ago and spun freely when installed. Preload is fixed as my car has an early style CSB, but there is preload on it. Guibo is only 2-3 mos old and showed no signs of damaged when I reinstalled it on the driveshaft 2 days ago. I wasn't able to get a good look of it on the car last night trying to troubleshoot it. Trans mounts are good, inspected this week, motor mounts were not inspected but are only about a month old.

Now I made alignment marks on my driveshaft/flanges/guibo when I removed it, and the driveshaft shop painted over them, that wouldn't be it would it? Also, I had to guess at the 13ft-lb to torque the slip coupler to, would that be it? With this job I discovered I set up that slip coupler completely wrong the time I did the E36 driveshaft years ago, and that one still worked fine. My roommate regularly installs BMW driveshafts rebuilt by this shop, and he says he never even touches the slip coupler, but this on was only finger tight when they delivered it to me.

My roommate the BMW mechanic is going to drive down to my work after he gets off today, he's much better with this stuff than I, but he's a little perplexed by this.


Thanks a ton.

[TobyB]

On the 2002, I had a diff flange work loose- then the pinion was free to wiggle,
and it vibrated like hell. Had to have happened very quickly, as I'd swapped
diffs for that weekend, and it was fine when installed.

I suppose the trans flange could do it too.

Seems unlikely you wouldn't notice it, but worth checking.

And no, the driveshaft needs to be aligned internally, but not to the car.

t

[Vincent Brick]

Its looking like a halfshaft is binding slightly, despite the symptoms indicating in the Bentley manual to be drivesahft. The problem has turned out to be completely intermittent.

On the plus side, my car needed a driveshaft anyway, I can certainly feel the difference in driveline lash with the new U-joints, and my CSB was def on the way out. AND, I'm getting a used halfshaft for free this week, so I've got that going for me, which is nice. (in Bill Murray voice)

[walktheboard]

Has this been fixed? I'm having a very similar issue with mine.

I've also replaced the driveshaft(new unit), CSB and guibo.