shuddering/banging/thumping under hard acceleration/torque - I'm stumped - HELP

[Sh3rpak!ng]

I had very similar issues and it was the u joints. Driveshafts aren't that expensive anymore, thankfully.

where are you buying driveshafts? ecs lists it at $830

[Cephas]

Well I paid about that for mine from the dealer, but I wanted genuine. It lasted 25 years so its worth it. Driveshaft specialists in TX list them from 378 to 428 though I never called them to check. Thats just after a quick google search. You may find better.

[Sh3rpak!ng]

Well I paid about that for mine from the dealer, but I wanted genuine. It lasted 25 years so its worth it. Driveshaft specialists in TX list them from 378 to 428 though I never called them to check. Thats just after a quick google search. You may find better.

Yikes! power to you for buying a new one. Wish I could do the same, but I've blown my budget for this damn build like 3x over.

My choices ranked:
1) attempt changing the joints myself
2) get a local shop to rebuild it
3) buy a rebuilt DS from beyer driveline (they modify for replaceable joints) or Driveshaft specialists in TX

[CorvallisBMW]

I've heard excellent reviews about these guys: http://www.driveshafts.com/markets/V...ck-Driveshafts

Unfortunately you'd probably get bent over on shipping charges.

[Balleristic31]

How are your rear subframe bushings?

EDIT: jk didn't read the whole post till after I posted this.

[Sh3rpak!ng]

I've heard excellent reviews about these guys: http://www.driveshafts.com/markets/V...ck-Driveshafts

Unfortunately you'd probably get bent over on shipping charges.

well at least it's on the same coast. I'm wondering if I should even bother attempting to replace the joints myself... don't want to damage it and lose a core charge or render it unable to be rebuilt...

and of course I don't know for sure the DS U-joints are the culprit. They both seem to move freely to me. But I guess the issue could be only manifesting while under torque

[arch4ngel]

Another vote for driveshaft u-joints.
My 535i had the exact same symptoms including shredding a nearly new csb.
The u-joints had the smallest amount of play in them but made the driveline feel like it was about to come through the floor.

Replaced it using a driveshaft specialist rebuilt unit, worked great for the rest of the life of the car.

[Sh3rpak!ng]

Another vote for driveshaft u-joints.
My 535i had the exact same symptoms including shredding a nearly new csb.
The u-joints had the smallest amount of play in them but made the driveline feel like it was about to come through the floor.

Replaced it using a driveshaft specialist rebuilt unit, worked great for the rest of the life of the car.

Interesting. Where was the "play"?

[arch4ngel]

The part connecting the two u-joint sections.
The play was evident when moving the driveshaft around while holding each side of the u-joint if that makes sense.

[Sh3rpak!ng]

The part connecting the two u-joint sections.
The play was evident when moving the driveshaft around while holding each side of the u-joint if that makes sense.

It does. Thanks

[pandaboo911]

shuddering/banging/thumping under hard acceleration/torque - I'm stumped - HELP

Check and make sure your driveshaft isn't hitting the gas tank saddle. Mine was contacting right where the little balancing weight was and caused a knocking sound at low speed/hard accel. Only in 1st and 2nd. Look at the balancing weight and check if the paint has been rubbed off. Mine didn't contact while parked.

This happened after installing aftermarket poly bushings. Temporary solution was to space the diff down with a few washers

I'm pretty certain that your driveshaft has excessive play and is hitting the gas tank or shifter linkage when you put a high torque load on it.

[Sh3rpak!ng]

Check and make sure your driveshaft isn't hitting the gas tank saddle. Mine was contacting right where the little balancing weight was and caused a knocking sound at low speed/hard accel. Only in 1st and 2nd. Look at the balancing weight and check if the paint has been rubbed off. Mine didn't contact while parked.

This happened after installing aftermarket poly bushings. Temporary solution was to space the diff down with a few washers

I'm pretty certain that your driveshaft has excessive play and is hitting the gas tank or shifter linkage when you put a high torque load on it.

Ill take a look at that too. That's kinda what it felt like. As if the DS was loose and banging around.

[MatRacer]

I had a bad driveshaft from loose u-joints. It wasn't really vibrating in 1st gear. It was more speed related than torque related. Even Under max torque (1st gear) the vibration wasn't really present. It was starting at like 35-40mph. Even at constant speed, if the culprit was the DS, I think it would vibrate, at least thats what mine was doing. Got it rebuilt and 80% off the vibration is gone.

When you think about it, a loose U joint creates a unblalance rotating mass (due to misalignment caused by the play) which will vibrate under rotation. The more RPM the more it vibrates. Load may increase it, but I dodn't see it as the main vibration catalyst.

I also had a failed CSB when I bough tmy last e30, an nothing at constant speed, but hard bing bang Under hard accel from rest in first gear (M20 auto...haha).

Hope this help you

[Sh3rpak!ng]

Well, looks like it is the guibo as previously suggested. Thumbs up to those who pointed there. I apologize for blowing that off as the culprit. I had only taken a quick glance at it before. Upon further inspection I noticed a missing bolt and cracking/tearing rubber around all the bolt holes on the back side. So I'm gonna say that's probably the issue. I'll replace it and report back.

[Sh3rpak!ng]

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