[E92_William]

Hello I've been chasing vibrations in this car ever since I bought it. It vibrates mostly on the floor and sometimes on the wheel. My car is xdrive but has no front driveshaft so basically RWD automatic.

As my latest attempt to fix it, I put it on stands and ran it up to 60-70 mph. The car would begin to seriously vibrate at around 40 and get really bad at 60. On the highway it vibrates over 60.

I then removed the wheels and ran it up to speed with no wheels on and it still would vibrate the same.

So now I'm wondering if this is the driveshaft? I can't visually see anything vibrating from looking under the car from the cv axles. But can't see the driveshaft u joint too well.

The car had the front Guibo and center support bearing replaced a year ago with no improvement, so I think the U-joint might be bad? The xdrive driveshaft has 1 center U-joint instead of 2 on RWD

[E92_William]

Did some testing today. Ran it with the wheels on and almost all wheels are out of round…

Either way I took them off and ran the car again and I still got noticeable vibration.

Decided to try and rule more things out and removed the two rear cv axles. Now there's no vibration at speed. So what's the issue then? Axles look good, no ripped boots!

https://youtube.com/shorts/_-ONrlAP9GI?feature=share

[Brian86]

You should be able to differentiate between wheel frequency vibration and driveshaft frequency vibration.

Bent wheels shouldn't cause vibration when the car is up in the air. After all, they were balanced that way.

Half shafts shouldn't really cause vibration unless they are in very very poor condition. You'd be able to tell if they were that bad when you were disconnecting them.

I'm still going with driveshaft/ujoint. By removing wheels then further removing the halfshafts it's changing the loading on the u-joint which changes the way the shaft behaves.

I got lucky and found a good deal on a low mileage shaft in a junk yard.

www.car-part.com

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So far chasing vibrations I've changed:
Front driveshaft
Transfer case (bad front output yoke due to bad front driveshaft ujoint)
Rear driveshaft assembly
Guibos

The last step, and I'll know tomorrow or Tuesday, was to straighten my bent wheels. 6/8 had 'run flat tire' bends. Some of them had several. I'm optimistic, since the car rides all but perfectly on a set of 17"ers off my M3.

[autoart]

I think I saw where someone had a vibration issue and his parking brake was the problem. It was not adj. correctly. Try removing the rear disk.

[E92_William]

Originally Posted by Brian86

You should be able to differentiate between wheel frequency vibration and driveshaft frequency vibration.

Bent wheels shouldn't cause vibration when the car is up in the air. After all, they were balanced that way.

Half shafts shouldn't really cause vibration unless they are in very very poor condition. You'd be able to tell if they were that bad when you were disconnecting them.

I'm still going with driveshaft/ujoint. By removing wheels then further removing the halfshafts it's changing the loading on the u-joint which changes the way the shaft behaves.

I got lucky and found a good deal on a low mileage shaft in a junk yard.

www.car-part.com

------------------------
So far chasing vibrations I've changed:
Front driveshaft
Transfer case (bad front output yoke due to bad front driveshaft ujoint)
Rear driveshaft assembly
Guibos

The last step, and I'll know tomorrow or Tuesday, was to straighten my bent wheels. 6/8 had 'run flat tire' bends. Some of them had several. I'm optimistic, since the car rides all but perfectly on a set of 17"ers off my M3.

I mean it was a pretty wild difference from no wheels and halfshafts on to having them off. With them off there's 0 vibration. 6th gear 2500rpm. If it ends up being the driveshaft I have a very low mileage one on sight just don't want to throw parts at it.

Let me know how your wheel repair job goes and the results. I have style 342s and like them a lot and pretty much can't buy them new so if they're bad I need to repair them

Will be checking the wheels by turning by hand on the front axle today and see with a reference point if I can see anything. I think it's very unlikely all 4 wheels are fucked.

[E92_William]

Originally Posted by autoart

I think I saw where someone had a vibration issue and his parking brake was the problem. It was not adj. correctly. Try removing the rear disk.

I forgot about this yesterday. Will definitely try that out when I get a chance to Jack up the rest again. I really dislike how sketchy it is to lift from the rear differential. Rotors are new in the rear and recent

[E92_William]

Could the angle that the suspension was at cause an issue? I was thinking I'm testing with the car jacked up and suspension fully extended in the rear so maybe half shafts vibrate at that high angle? Trying to see if the vibration on stands is not a real problem and the issue so actually the wheels

[Jaronbwall]

Holy shit this is amazing. Thank you for posting this! I never thought of lifting the car and running it in 1st gear. I'm suffering from vibration around 20mph. It's been bad for a few years but the car wasn't a daily driver and never got worse. I'm fairly sure it's a bad CENTER SUPPORT bearing. This test could help confirm my suspicion.

Also, WHY the hell are you driving an x-drive with no front drive?

[autoart]

I always jack it up from the cross member in front of the dif.

[Brian86]

Originally Posted by E92_William

Could the angle that the suspension was at cause an issue?

It's possible? But they call them CV joints for a reason. The bearings could be riding in and out of the wear groove when the suspension is drooped. Generally wouldn't notice that when cruising with weight on the suspension.

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I like to check for bent wheels by putting them on a non-driven axle, then just spinning them by hand, either with a tape measure hanging from a control arm, or just letting my thumb ride between the wheel and the lower ball joint as it spins.

I was pretty dismayed at how badly damaged mine were. Little 16"x7 #156s too. I'm used to the lips being a little beat up from curbs, but I had something like 11 or 12 discrete bends, all on the inside, and all down to the bead, amongst 8 wheels. Basically that's run flat tires on north east potholes.

Another test for bent wheels is to tweak tire pressure. It'll vibrate worse with high pressure, and less with low pressure. Make big changes. 40psi vs 25psi.

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I've only experienced parking brake vibration as a very binary thing. Either it doesn't do it, or it's 'holy crap I think the subframe is about to fall out' kinda violent shudder.

[E92_William]

I just checked all wheels and tires for runout by slowly turning them with a reference point to keep track of any changes, in this case a flathead screwdriver.
The findings:

Both front tires are perfectly round with no issues, wheels are good too except for passenger side front having about 1/8 in bend outward but radially there isn't any change in roundness it seems.

The rear wheels are both perfect, no bends at all. The tires however seem to be between 1/8 to 9/64 in out of round around their diameter. These are some cheap Atlas tires.

I need to replace the rears anyway as they're down to the wear bars so maybe that will provide an improvement. Still doesn't explain vibration with them off the car.

I think the way to check if the CV axle angle is the issue in my test is to jack up the control arms to ride height and try again. If that doesn't result in an improvement in the test I will remove the rotors.

[E92_William]

Originally Posted by Jaronbwall

Holy shit this is amazing. Thank you for posting this! I never thought of lifting the car and running it in 1st gear. I'm suffering from vibration around 20mph. It's been bad for a few years but the car wasn't a daily driver and never got worse. I'm fairly sure it's a bad CENTER SUPPORT bearing. This test could help confirm my suspicion.

Also, WHY the hell are you driving an x-drive with no front drive?

If this was a driveshaft issue I think it would be very noticeable and visible so worth a try. I have the front axles and driveshaft off because these parts failed and I didn't want to put the new parts back in as the car drives much better like this!

[E92_William]

Originally Posted by autoart

I always jack it up from the cross member in front of the dif.

My small floor jack is already having a hard time just doing the diff so imagine having to go higher for the crossmember. Seems easier though

[bbnks2]

check for lateral run out at the hub face

[E92_William]

Originally Posted by bbnks2

check for lateral run out at the hub face

Will try that when I get a chance to remove the rotors.Might check with the rotors on to see if it's fine before hand

[mweisdorfer]

Check your engine & trans mounts

[Brian86]

Straightened wheels fixed the last vibrations. The e91 is nearly as smooth as when it rolled out of Munich. About 98+% of perfect.

It takes a special kind of crazy to spend $500 to straighten two sets of #156 wheels on a 300k mile station wagon.

[Jaronbwall]

What should I be looking for when checking the engine and transmission mounts? I had my car on jack stands last night and the sound went away. I ran it in 1st and 2nd gear up to 30mph. NO VIBRATION or sound. Now I'm guessing it's something in the front end. Replacing tires this week.

[mweisdorfer]

Originally Posted by Jaronbwall

What should I be looking for when checking the engine and transmission mounts? I had my car on jack stands last night and the sound went away. I ran it in 1st and 2nd gear up to 30mph. NO VIBRATION or sound. Now I'm guessing it's something in the front end. Replacing tires this week.

Personally, I'd say if your trans & engine mounts have over 150,000 miles on them it's time to change them out.

The fact that you can't feel the vibration while on Jack stands makes me think it's something to do with the wheel. Did you have a 4-wheel alignment done as well as have all 4 rims checked for balance?

I'd start there..

[Jaronbwall]

Originally Posted by mweisdorfer

Personally, I'd say if your trans & engine mounts have over 150,000 miles on them it's time to change them out.

The fact that you can't feel the vibration while on Jack stands makes me think it's something to do with the wheel. Did you have a 4-wheel alignment done as well as have all 4 rims checked for balance?

I'd start there..

Thanks for replying man. I'm at 108k miles. Car had an alignment done last summer after I installed control arms. That fixed the steer wheel vibration at highway speeds but the 25mph vibration/sound was going before all that. I hit a pot hole about 2 years ago and destroyed a rim but I bought a new replacement. This has been my weekend/fun car for years... The inside edge of the front right tire was out of round and worn a bit more than the left.
I'm leaning towards that front right/suspension, toe-arm?

[E92_William]

Did you run it with or without wheels? 30mph is not enough. Without wheels mine was fine up until 40. With wheels 30 began to get bad.

I'm waiting this weekend to be able to dig deeper into my issue. If wheels need straightening that's fine if it solves it. I'd like to know if your car is still good at higher speeds in stands so I could rule out my theory of cv axle angle causing it

Could also I guess try put your front tires in the back while on stands

[mapleleaf1773]

I've had some vibrations up front in my 3 series lately. I had a shop balance all 4 of my wheels and the vibrations are gone.

I have to say, pot holes have caused all of my wheel bent issues lately. Its very hard to dodge every single hole. I even have one cracked wheel but its not to bad at the moment.

Seems like I'll be scoping out new ones in the future. On the other hand, I'm glad its the wheels and not the driveshaft etc...

Knowing is half the battle, sorry to hijack