Front wheel wobble

[Coyote_ar]

Hi guys, so im having this problem for a while now. At 90-100kmh, my front wheel wobbles. If i turn the steering wheel slightly to either side, it stops. Also under light braking, again it wobbles. If i step on the brakes hard, it stops. And finally when driving, if there is some kind of irregularity in the pavement, the front of the car will move sideways following that irregularity (its not something too extreme, but you can feel the nose of the car moving).

At first i had some play in the idle arm bushing. I replaced that and it reduced the wobble a bit, but still present. I also tried tightening the steering box bolt, and that again helped to reduce it a bit, but it makes the steering quite heavy. And the problem is still there anyway.

I've read that many cases with similar problems is related to the thrust arm bushings (http://www.bmwe34.net/E34main/Maintenance/Suspension/Upper_arm.htm)
. But i've tried moving them and they dont seem to have any movement. Is there any way be sure its the thrust arm bushings?

Regards

[632 Regal]

Any play or sloppyness causes the infamous wheel shimmy. Most likely the thrust arms and bushings and can be bought cheap on ebay. You should check everything for play before you just replace something here and there. Your whole front end may need to be replaced (IE tie rods, center link Plus thrust and control arms) Take a peek around in here: http://www.bimmernut.com/forum/forumdisplay.php/15-Suspension-amp-Steering

[shogun]

Upper thrust arms often, bur also the steering links http://www.bmwe34.net/E34main/Maintenance/Steering/steering_link.htm
The last time we fixed that was a problem with the center steering link, the joint was too lose and it wobbled like hell at certain speeds and road condition. Before we found out that we replaced/changed for tests: wheels with tires, front shocks, upper and lower arms (were also shot), outer steering links, pitman arm, idler arm, driveshaft center bearing (also shot), engine mounts (were shot), and the trans mounts were also shot. And also the dogbones were shot.
But in the end, the big problem was the center steering link, the ball joint was tool lose. After we removed the center steering link, the one ball joint could be moved with 1 finder, so lose it was.


Also read this thread: E34 steering centre tie rod: RHD and LHD the same http://www.bmwforums.com.au/showthread.php/44738-E34-steering-centre-tie-rod-RHD-and-LHD-the-same
The pre-loaded side goes to the idler arm side because the idler arm is just moving in the bush, but has no ball joint, see here http://www.bmwe34.net/E34main/Maintenance/Steering/steering_link.htm

[Coyote_ar]

i feel this wobble, and a really hard flex, on the front right wheel. not on the left one. nothing at all from the left side. when im braking hard, you can feel like the wheel is moving backwards.

would the steering related bits cause a problem on a single side?

[632 Regal]

i feel this wobble, and a really hard flex, on the front right wheel. not on the left one. nothing at all from the left side. when im braking hard, you can feel like the wheel is moving backwards.

would the steering related bits cause a problem on a single side?

Absolutely! Sounds like the thrust arm bushing is shot. See if you can pick some* complete arms with bushings on Ebay, the chinese ones have come a long way in quality compared to a few years ago. The reason to get the arms with the bushings is that you can replace just the bushing but the chances are the ball joint is also shot so do it complete and not worry for another 100K miles.

*Although not mandatory it is always recommended to replace both sides at the time.