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View Full Version : Vibration when accellerating in each gear


timmycb
11-22-2004, 10:23 PM
Hi folks,
I just aquired a 1985 735i. Lots of nice goodies, also lots of things to fix. My most worrysome problem at the moment is a low vibration that starts when accellerating from stop in 1st gear. One the rpms get to about 2000, it goes away. this repeats going into 2nd gear but not as bad. 3rd and 4th aren't noticeable. The last car I had that felt this way was an Oldsmobile - harmonic balancer unit had come apart. I haven't been able to fine anything on-line about a balancer for these cars. any ideas or suggestions would be most welcome.

Thanks

Tim

Betray
11-24-2004, 01:53 AM
wouldnt know... try a bigger forum with more 7ers.. we are so rare in this forum

Gullwing
11-25-2004, 12:57 AM
This is DEFINITELY your driveshaft U-joint. Unfortunately the u-joints on the older bmw e23 7 series are not serviceable so you will have to buy a new driveshaft. Been there done that.

EMPOWERD
11-25-2004, 01:02 AM
There's a good chance it's your driveshaft flexdisc (guibo).... it's made of rubber and often breaks with age. U-joints are less prone to failure.

Eurostyle
11-25-2004, 01:08 AM
My guess would be the hanger bearing...In most cases the rubber around it cracks, then breaks off, causing heavy vibration and a banging sound in the low gears...

Gullwing
11-25-2004, 01:10 AM
Guys, ITS THE U-JOINTS, TRUST ME.

Edited to add : All seven series e23 with manual transmission came with a guibo (flexdisc) , but most e23 with auto trannies have NO GUIBO.

timmycb
11-25-2004, 11:17 AM
Thanks everyone. I'll be under it shortly so we'll see what we see. Luckily, there is a drive train specialty place not too far from me so if replacing the whole shaft is needed I can get a decent deal (I hope!)

Have a good Turkey Day...

timmycb
01-07-2005, 11:45 AM
I finally got to tearing this thing down and the center support bearing was completely trashed. U-joints are fine. Don't have a guibo though! Bearing and support coming from BAV so he should be back on the road tomorrow...

*th-up* Thanks...

cwiniarz
01-07-2005, 06:24 PM
is it a difficult job to put the bearing in, do you have to take the driveshaft off. I also need to replace mine

timmycb
01-07-2005, 07:25 PM
Yes you do. The drive shaft is two pieces with a u-joint and splined shaft in the center. The bearing is right around the join. I had to drop entire exhaust to get it out. Wasn't terribly hard except for those self locking nuts on the front and rear u-joints.

cwiniarz
01-08-2005, 06:40 AM
thanks i need to do mine soon aswell, but i think my u joints are going so just a little more work.