Driveshaft/CSB Problems

[themitchster359]

I recently replace my entire driveshaft/CSB and flex disc with new bolts, etc. I replaced it because the CSB bracket hoop thing broke off the bracket, so the driveshaft was just bouncing around. I also repaced my CAB with poly from BavAuto.

I got the car back on the road, drove awesome, no vibration and no chattering with hard acceration. A day later, when I get on her from a roll in 1st gear, and shift to 2nd, the hard chatter starts again. I'm like wtf, I just replaced it!!! The difference this time, it that there is no vibration at any cruising speed like there was before.

Do you guys think my tranny mounts, rear bushing, etc are going bad? The car has 150k almost on the chasis. The only thing that I'm worried about is that the chattering is coming from the same place before.

Any input would be helpful. I haven't gotten back down there to see if my CSB broke or is breaking again...

[jlevie]

Are you saying that you installed a new (or rebuilt) drive shaft, CSB, abd guibo? If that is the case and none of the fasteners have loosened, I'd suspect transmission, motor, and diff mounts for starters.

However, if the replacement items were just the guibo and CSB and you re-used the drive shaft, I'd say the cause of the CSB failure was binding u-joints in the drive shaft. In that case the full fix won't be had until a new or rebuilt drive shaft is installed.

[themitchster359]

i had a rebuilt driveshaft with the CSB already pressed in. I'm gonna look into the all the fastners and mounts, b/c I don't get it why the same chattering would start again after I repalced the freaking entire piece!

[jlevie]

Unless there was something wrong with the rebuilt, you need to look elsewhere for the cause.

[themitchster359]

do you guys think it might be a subframe bushing/tranny mount issue?? the tranny mounts look decent, but i can't really see if the subframe bushings are bad. the outer rubber lip (on the bottom part that i can see - i'm not sure if im looking at it right either) looks old and decayed from the looks of it.

[Leaf]

bump

[themitchster359]

no kidding. i have no freaking clue.

[jlevie]

Have you tried getting the rear end of the car up in the air, removing the rear wheels, and running up through first and second while someone watches the drive shaft? Light application of the brakes while doing this will load the drive train.

Unless you have; a) a lot of experience with E30's, b) a new pair of trans/motor mounts to compare, a quick look at them may not reveal how bad they are.

As to the rear subframe bushings, it would be a safe bet to say that they need replacing on almost any E30.

[themitchster359]

well experience with them...i guess some, but this is my first drivetrain problem and I guess I am still learning alot. i dunno man, it's reall hard to tell.

before when the CSB was going out, I had vibrations around 35 to 50 mph with the same chattering/thomping sound. this time i get the chattering/thomping sound w/o the vibrations. the car drives smooth as silk if i don't rap out 1st gear hard. i haven't really gotten on it since the few times i've felt/heard it.

my buddy thinks it might be some "wheel hop" from the driveline somewhere b/c of worn out bushings/mounts.

[themitchster359]

also, thanks for the help..i know its a bitch trying to diagnose a problem online.

[StereoInstaller1]

Motor mounts and tranny mounts on these cars can do just what you are describing.

Jim will help you get straightened out.

[themitchster359]

well the problem was bad rear subframe mounts. they are fucked.