Rhythmic vibration at 70mph+

[noid]

Having a weird vibration problem at 70mph+, tried taking it up to 95mph and only got worse with speed.

With the car in neutral the vibration is still there, with brakes applied it still there, no weird grinding noises, turning has no effect.

Tried swapping rims/tires with known good; same problem.

Checked that all calipers, tierods, control arms, shocks, etc were all tight.

Drive shaft is new (OEM BMW), all wheel bearings are new (FAG), all suspension components (including all rubber bushings) are less then 2 years old.

Even while holding speed the vibration seems to get slightly better then slightly worse, rinse and repeat; in a rhythmic way.

Very hard to tell if its coming from behind or in front.

Any ideas?

[Bearmw]

CSB preloaded or driveshaft angle incorrect?

But if its doing it in neutral then maybe you lost a wheel weight?

[jeffnhiscars]

I thought of a wheel weight but if he's still at highway speed when he puts it in neutral,it could still be the drive shaft as you suggest. It's just being driven by the diff and loaded in the opposite direction.

What was the last thing you replaced before you noticed the vibration ?

[Sps]

Check and see if you are "dog legging". Have someone drive behind you and have them check if your driver's or passengers side is more visible while directly behind you. A rear arm may be bent and the vibration is from the car trying to keep itself straight. If it gets bad enough, you may eventually feel a slight bounce also.

Your driveshaft will also keep rotating when you put it in neutral, but it will no longer have load on it. So don't rule out a driveshaft component problem.

[noid]

I store the car during the winter and often do a bunch of work, so its often hard to pinpoint one thing I have changed to check.

However, I noticed some steering wheel shake and decided to point my focus to the front end.

My steering rack seems to have some movement which I have captured here (recommend to watch with sound):



Can someone check their rack and see how much movement theirs has behind the inner tierod balljoint?