Steering shake: Thrust arms vs. steering rack?

[fredzman]

Hi,
I've had issues with steering wheel shake since I bought the car. When using winter wheels for the season up here in Scandinavia with "balloon tyres", problem was gone and I've kind of forgotten about it.
Now that i've recently switched back to summer (225/40/18), problem is very distinct again.

What I've done:
- Straightened up the rims at rim workshop (they were little bent) + wheel balancing
- Replaced lower control arm, right side (Noticable play in bushing)
- Replaced outer tie rod both sides

Diagnosed:
When both wheels in air, I can move one wheel a little side-to-side and see the other wheel move simultaneous. Not much, but it's noticable.

When jerking the hub/wheel on one side, I can feel the play all the way into the steering rack (Outer and inner tie rod is tight in the movement, all the way into the teethed rack wich is moving). Maybe 2-4 mm.

Now, I guess that means my steering rack is worn and needs to be replaced. Can someone confirm that this a bad rack on the E39?

Now for my question..
Bad thrust arms bushings are known to cause steering shake. Can replacing them help "tighten up" the hub, in wich may cure the shaking? Like it somehow "pushes" the hubs outwards to their neutral position, so it takes away the little play from the steering rack itself?
I can live with a tiny bit of deadzone on the steering, but no shaking.

I have not checked my bushings yet, but I'm sure they are worn and needs to be replaced.

Are there any logical sense in this? :rolleyes Should I try to replace thrust arm bushings before steering rack in this scenario?

[fredzman]

Anyone?

I also replaced front rotors & brake pads btw, it helped on the shaking when braking, but problem still exists at cruise speeds on 70 km/h+, some times more noticable depending on the road condition (as the car also wanders on uneven roads..)

Does it sounds like the rack is the cause of steering wheel shake/wandering?
Should i give it a try replacing the thrust arm bushings first?

Thanks guys.

[ezbmr]

Sounds like thrust arm bushings and perhaps an alignment. There are a lot of places that will give you a free alignment check.

[crazy4trains]

I would be concerned about your wheels. How did the "rim workshop" straighten your wheels? If you can put your winter tires on and the problem goes away then you have found your problem, haven't you?

[jstern]

Do you know how many miles are on your thrust arms? The bushings start leaking (they are fluid filled) at about 75K miles. Sometimes you can see stains of where the fluid leaked out. When replacing make sure you buy Lemforder arms with Meyle solid bushings. They last longer.

[fredzman]

I would be concerned about your wheels. How did the "rim workshop" straighten your wheels? If you can put your winter tires on and the problem goes away then you have found your problem, haven't you?
Good thinking there, problem is that I lied.. With winter tires I could also feel the vibration at times in high speed, but it was almost not noticeable. I figured it has to do with big rubber tires.

With summer tires the vibration is also random! Sometimes I cruise with almost no vibration at all. Then it comes back. Seems like it depends on the road. And the wandering itself is an issue. I do believe it is related to the car..

Rim workshop with heating up the aluminium and some kind of hydraulic equipment with fancy gauges that should straighten the rims.


Do you know how many miles are on your thrust arms? The bushings start leaking (they are fluid filled) at about 75K miles. Sometimes you can see stains of where the fluid leaked out. When replacing make sure you buy Lemforder arms with Meyle solid bushings. They last longer.
I don't know mileage. I am going to replace the thrust arms tomorrow and we'll see what happens.. I'll report back..

[Trainwreck914]

If you have play when moving the wheel side to side then it could possibly be your hub bearing. Do you hear and humming or whirring that gets louder the faster you go? Shimmy could also be bad tires/rims. As you state you had the rim fixed. Could have NOT been done properly. There's a number of components that could cause the shakes.

[ViolinARC]

It sounds like you have a combination of front wheel hub bearings going bad and the need to replace those poorly designed TAB's. I spent uber hours troubleshooting this problem, which included the dreaded shake-n-brake (NOT warped rotors guys). I re-balanced, resurfaced and replaced rotors, etc. and the shake would go away TEMPORARILY. The last time I replaced the entire thrust arm with Lemforder (both sides of course) and the shake went away, for about a month, before returning with a vengeance. Upon further inspection, I discovered that the new thrust arm bushings had failed (yes, I preloaded the suspension before torquing)! This time around, I just replaced the TAB's with PowerFlex Track Black and VOILA...the shake is eliminated.

When the front hub bearings failed, I was experiencing wandering and tracking problems with odd DSC behavior (kicking in even during the most minor curves). I replaced with cheap aftermarket (big mistake) the first time around and finally settled on Timken for perfect operation.

Hope you find this info helpful. Let us know how things work out...:eatpop:

[fredzman]

Thanks,
I've replaced the thrust arms today after a bit of struggle. The seperator tool for ball joint wasn't large enough so I had to shorten the bolt with the tool at hand: a hacksaw. To be able to saw it over I had remove the brake discs also.

And when lowering the whole hub to its lowest, I still had very limited space to get the ball joints out/in. The steering/tie rod was at it's fullest and limited the hub height adjustment. Could remove the outer tie rod ball joint, but I got it in there at last.. Odd this isn't mentioned in any DIY's for thrust arm replacement ...

So. A lot of struggle for... not very good results :(
The front end is somewhat tighter and the road wandering is better now than before. But it's still not good and still vibrating on the steering.

I therefore suspect my steering rack. I can actually feel the teeths is a bit worn in the center area, b.c it's easy on the wheel there and gets a bit harder when turning left/right.

I also suspect my wheels or tires is still not 100% round.

Where to begin... Old car, high milage and too much $ :mad

About the wheel bearings, I think they are in good condition, no bad sounds or any play. BUT when working on the car today, I noticed the brake pads are touching the disc a bit on/off. I could spin it, but it was rubbing.. Is this an issue? Could it be this simple? The rotor is not warped, I replaced them a while ago, and under braking my steering is actually tight (no shakes).

[energizedmortal]

Thanks,
I've replaced the thrust arms today after a bit of struggle. The seperator tool for ball joint wasn't large enough so I had to shorten the bolt with the tool at hand: a hacksaw. To be able to saw it over I had remove the brake discs also.

And when lowering the whole hub to its lowest, I still had very limited space to get the ball joints out/in. The steering/tie rod was at it's fullest and limited the hub height adjustment. Could remove the outer tie rod ball joint, but I got it in there at last.. Odd this isn't mentioned in any DIY's for thrust arm replacement ...

So. A lot of struggle for... not very good results :(
The front end is somewhat tighter and the road wandering is better now than before. But it's still not good and still vibrating on the steering.

I therefore suspect my steering rack. I can actually feel the teeths is a bit worn in the center area, b.c it's easy on the wheel there and gets a bit harder when turning left/right.

I also suspect my wheels or tires is still not 100% round.

Where to begin... Old car, high milage and too much $ :mad

About the wheel bearings, I think they are in good condition, no bad sounds or any play. BUT when working on the car today, I noticed the brake pads are touching the disc a bit on/off. I could spin it, but it was rubbing.. Is this an issue? Could it be this simple? The rotor is not warped, I replaced them a while ago, and under braking my steering is actually tight (no shakes).

before you suspect that it is the rack grab the lower steering column and pull on it- does it have play or knock? I found a used lower steering column on ebay for $30 with 96,000 and it cured my steering wheel vibration. Are your tires wearing evenly all around? Good luck

https://www.youtube.com/watch?v=bwT1_Lv9fz4

[RyansBMW]

Do you know anyone with an E39 near you that is vibration free? If you do, swap wheels and see what happens. Get this possibility eliminated 1st before throwing more money at the car.

[fredzman]

before you suspect that it is the rack grab the lower steering column and pull on it- does it have play or knock? I found a used lower steering column on ebay for $30 with 96,000 and it cured my steering wheel vibration. Are your tires wearing evenly all around? Good luck

https://www.youtube.com/watch?v=bwT1_Lv9fz4Edit: Sorry, too fast there.

I think steering column and U bolt is tight, will check again.

Got another theory that since the tire is old (but even), it's hardened, and I therefore feel every detail of the road and makes it shake a lot easier. I dunno. I will try another set of wheels and tires to eliminate this first.