Driveline vibration - expert advise pls

brothersinc1 · 10-12-2009, 05:52 PM

Hello, 96 328i 120,000. Replaced driveline, quibo, center bearing all from Portland Driveline. Now I have a new vibration. Feels Like a back message in the drivers seat at 40mph+ Warranted out the driveline. Installed new driveline and still have vibration. Different but still there. Here is the weird thing after I drive for 10 minutes the vibration starts to lessen. After a 20 minute drive the vibration is almost gone. But doesn't go away completely after that.

Tranny mounts look good. Tires recently checked and balanced.
Guibo installed properly.

Vibration same under acceleration and deceleration and neutral.

Question. Why would the vibration go away after the car is driven for 10 minutes. Does something warm up and become more forgiving? Maybe a wheel bearing. I cant hear any noises.
Thanks for your help.
Rob

bazar01 · bazar01's Garage

Something is out of balanced in the clutch bell housing area. Is the clutch and flywheel still original?

GearHeadPeter · 10-12-2009, 06:54 PM

I have a 98 328i, and also had a similar vibration. Like you I had the drive line replaced again, but still had the vibration. In my case where the drive-shaft attached to the differential there was a small burr that interfered with a flat alignment of the tail section to the differential. When the ground down the burr the vibration went away.

I did all the same things you did, but I replaced my transmission mounts just to be sure.

Hope it helped.

GearheadPeter

brothersinc1 · 10-13-2009, 04:06 AM

"Something is out of balanced in the clutch bell housing area. Is the clutch and flywheel still original?"

Hello thanks for your help guys. I forgot to say the car is an automatic.

If I have to pull the driveline again I will surely check the mating areas and probably do the tranny mounts because I am there anyway.

The original quibo did not have much damage some minor cracks. And the original vibration was more ujoint related (acceleration at low speeds). I am guessing because the original guibo was in fairly good condition that everything is aligned properly.

GearHeadPeter · 10-13-2009, 05:13 AM

I bought a new automatic drive-shaft, and when I put it in it would vibrate at about 70 mph. Luckily the manufacturer was in AZ and I took the car to them, where they found the burr, and ground it down. Unfortunately the vibration was still there, and they replaced the drive-shaft with another new one. Has been great ever since. I would definitely replace the transmission mounts as mine were pretty bad off.

Good luck.
GearHeadPeter

tm1100s · 10-14-2009, 07:01 AM

What brand tires do you have. And have you checked the rear subframe mounts?

bazar01 · bazar01's Garage

If the new driveshaft sits properly on the diff pinion flange, guibo is centered on the tranny output shaft and it still vibrates, the driveshaft was improperly balanced or a balancing weight came off the driveshaft.

brothersinc1 · 10-14-2009, 01:14 PM

Quote:

Originally Posted by tm1100s

What brand tires do you have. And have you checked the rear sub frame mounts?

I bought Michelin Exalto tires 225/50/16. I did not have any vibration when I drove on the Goodyear Eagle Tires. I left the tire shop with serious vibration. Balanced tires twice. Moved them around. Warranted 2 tires. Come to find out the driveline ujoint was the problem. The Michelin tires apparently are not as forgiving as the Goodyear and thus amplifying the wallered ujoint. Replaced the driveline and all was good at low speed. Definite difference except for vibration at 40+.

So I learned when you put on firm tire you feel the road and everything else in your car that is wearing out.

The mechanic said the tranny and sub frame mounts look good . I have not seen them myself so I do not know.

Thanks for all your help. Rob

GearHeadPeter · 10-14-2009, 02:08 PM

Rob, those are the same tires I have on my BMW, but I still think the rear assembly on the driveshaft is to blame as it was happening to me also. A quick test is to have you mechanic put the car on a lift, have someone in the car and put the car in drive and drive it.

Have the mechanic look at the tail section of the drive shaft by the differential and they should be able to see if it is in alignment or not. The shop also thought it might be my tires out of balance, but I had them rebalanced and it did the same thing.

I had to take the owner of the shop on a test ride as my vibration did not happen until I got to 72 mph, and he did not test the car past the speed limit of 65 mph. After my test drive the entire drive shaft was once more replaced and it has been ok since. You just have to insist that it be fixed, and don't take no for an answer.

Good luck,
Peter

brothersinc1 · 10-15-2009, 04:40 PM

Good news. I got a wild hair and moved the rear tires to the front and guess what .... vibration gone. This I can not believe. I am happy and mad at the same time. Happy because the vibration I loathed is gone. Happy because I do not have to tear the car apart. Happy because I now know the problem. But Mad .... very frothy, manifesting mad because I had the tires balanced 2 times for good measure. How can they not balance a tire? Or if the rim is bent, not say something. "Sir, the tire won't balance." "Sir the rim is bent"

o

.
I have spent 4 weeks banging my head on the wall. Shipping drive lines all over the country and $200 on a rabbit trail.
So apparently as the tire heated up it became more forgiving thus the vibration lessened. And why the offending tire does not cause the front to vibrate in the same manner I do not know. Maybe the weight of the engine.
I would have sworn on my death bed it was the drive line. I can not believe it was a tire. Oh well its fixed and that's all that matters. This mechanical nightmare is over. Maybe this will help another in crisis mode.
Thanks for all your input. Rob

tm1100s · 10-15-2009, 08:49 PM

I wouldn't have thought that about the Michelins, but cheaper tires seem to take a set overnight and don't shake it off until the tires heat up a bit. Maybe there's just enough 'give' in your front suspension to compensate for this. Can't explain it otherwise. Either way, good enough. And now you know all the rest of the work is good for a while.

Jeron · Jeron's Garage

My truck has a vibration at speed that goes away after a few miles. It is caused by the tires which sit for long periods of time and when I drive it it take a while for the tires to get warm and become "round" again.

I have a bent rim on my M3 that has a pronounced vibration if the rim is in the front but it is almost imperceptible if its in the rear.

bazar01 · bazar01's Garage

I also have the same experience with the 911 sitting in the garage for a week before it get's exercised. First 5 miles, the car shakes from the flat spot but goes away when tires get warmed up.

You would think vibration issue due to tires can be easily isolated. But since the OP did some work on the driveline made him think it was a driveline issue. To me driveshafts are hub centric so that should be ruled out immediately unless a balancing weight came off.

Good job on the fix!

GearHeadPeter · 10-16-2009, 12:47 PM

Hi Rob,

Good catch. I also had problems getting the front tires to balance until I too got a wild hair and decided to replace the front sway bar bushings and the end links that connect the sway bar to the lower control arm. Problem solved. Just a thought, and it is easy to do.

Peter