Steering wheel vibration

[Shipkiller]

I pull my calipers and swap rotors and pads for each track event. I cannot fathom how this was accomplished. I dont think the brake lines will reach...... A real Richard Cranium. .....

[Finnegan]

Originally Posted by goomanchu

....Mechanic discovered that at some point in the past, during a brake change - calipers were reversed side to side and inverted. So left caliper was on right wheel bolted on upside down....

All I can think of is a replacement caliper job done very wrong (someone didn't change their pads and killed the calipers) or a prior accident and repair done wrong.

[goomanchu]

Absolutely. shop that fixed it was not the shop that screwed it up. I don't know who that was. just baffling.

[jdoublehcubed]

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[jdoublehcubed]

Did the bushing swap today, wasn't too bad. But my wheel is still wobbling. I've got 75k on the clock, so I'm telling myself they would have needed it soon anyway, and I didn't completley waste my time.

[ZStig]

Originally Posted by jdoublehcubed

Did the bushing swap today, wasn't too bad. But my wheel is still wobbling. I've got 75k on the clock, so I'm telling myself they would have needed it soon anyway, and I didn't completley waste my time.

That sucks

[Blind32]

I get this wobble too. Just replaced FCABs, RTABs, Motor mounts, and back on OEM Trans mount and an alignment. Still have it. Seemed to be more pronounced when tires were cold. Might check the rubber bits in steering assembly. I seem to remember there is a guibo for the steering shaft. I'll let y'all know if I find anything.

[ZStig]

I have some oil on the middle rubber of my power steering rack, wonder if its damaged..

[jdoublehcubed]

Zstig: probably just the power steering trombone tube. All the factory installed one weep. I just wipe mine off when I'm under the car and make sure the fluid is topped off, its just not worth $300 to replace.

Blind32: try this: http://www.e90post.com/forums/showth...ng+dead&page=2
Next on my list of things to check. I haven't read anything about anyone having this problem on a Z4, but IDK what else to think with your list of stuff.

[BMW Maniac]

What tires are people running? I have the Conti DSWs....they just arent' wearing correctly. All I know is that my vibration COMES AND GOES....to me, that points to the rotating mass, aka, wheels/tires.....if the wheels are good, I'm betting one of the tires may be defective?

I have new control arm bushings waiting on me to install, but I don't think they are the culprit...with 60k miles, its just about time anyways

As soon as I get back, I plan to find someone to swap wheels with and check that way.

[Spedracer81]

Just a follow up, I found out my left front brake caliper was sticking, replaced it and 90% of the shimmy is gone..I attribute the last 10% to larger wheels & bad roads...

[BMW Maniac]

Unfortunately, I still have 10 more months to go, but just doing as much research as I can I have three courses of action that I will try, but I would suggest others trying:

1) replacing FCAB....just received mine from Tuner. Once I replace them, I'll verify. If the vibration is still there, I'll move onto #2.

2) Engine mounts....we already know that sometime the engine mounts fail. Might be an indication that we need to either replace the solid motor mount, or that perhaps the bolts connecting the mount to the engine are missing/loose....I think on page two, someone with this issue replaced their motor mounts along with their FCABs and other parts and the vibration disappreared....may have been linked to the mounts all along!

3) Sticking caliper....rebuild guides are cheap and having rebuilt a caliper before, it isn't hard.

[RobertRO]

Originally Posted by BMW Maniac

I have three courses of action that I will try, but I would suggest others trying:
1) replacing FCAB [...]
2) Engine mounts [...]
3) Sticking caliper [...]

I am sorry to disappoint, but I now can add three more entries to the long list of actions mentioned in my post above:
#13: Replaced engine mounts with Vibra-Technics ones. No effect on the vibration.
#14: Replaced front tires with Michelin PSS 235/45x18. It didn't cure the vibration.
#15: Retorqued the steering rack to subframe bolts. That significantly reduced the vibration - but it didn't totally cure it.

I haven't yet rebuilt the calipers, and I will probably have to do it sometime soon. On the other hand, my calipers are fine. They never stick.

Just one more note: if some of the front axle suspension and brake components are worn out or damaged, it is obvious that replacing them will have a positive impact on the steering wheel vibration. What is really annoying is that vehicles which seem to be in a very good technical condition still have this issue.
Both the BMW dealer and a similar topic on z4-forum.com suggest that the steering rack may have some internal play, which would be the cause of the vibration. But the steering rack is too expensive to be replaced just for fun, when internal play is not obvious.

[close_to_the_edge]

Dear RobertRo,

I have same problem, in that you clarfy in your previous post as A wobble.

But I feel the vibration in the bad roads. If the roads are good, without any roughness and shaginess there is no vibration.

Did you check it when you are in a smooth road?

Kadir

[tom_48]

Tires?

[thelinux]

My steering wheel shakes. It's not related to wheel because it shakes when the car is in park and idle. If I up rpm to 1000, then the vibration goes away. I feel like there is some mis-firing but I am getting no codes. I've been thinking that the cause is some bad sensor but now I think it could be a engine mount shot. But can't see anything wrong with them with visual inspection. Do I need to take them out to make sure it's not the engine mount?

[BMW Maniac]

Originally Posted by thelinux

My steering wheel shakes. It's not related to wheel because it shakes when the car is in park and idle. If I up rpm to 1000, then the vibration goes away. I feel like there is some mis-firing but I am getting no codes. I've been thinking that the cause is some bad sensor but now I think it could be a engine mount shot. But can't see anything wrong with them with visual inspection. Do I need to take them out to make sure it's not the engine mount?

Yes, that AREA is where I would look. If the actual rubber mounts seem fine, I would look at where the mount bracket connects to the engine itself. I know on the m coupe, they could be loose, or missing mounting bolts.

[StickMon]

I just started getting some light shimmy under high speed braking, so I figure it's time to put on the FCABs I've had sitting in the drawer for months.
Either that, or the ECS rotors have gone out of true after only 6500 miles.
I figured it was worth getting the BavAuto/Koch tools, rather than try it with my crappy old puller.
They arrived tonight, in a box twice as big and heavy as expected.
Inside the BavAuto box was a Koch Tools box.
Inside the Koch Tools box was a tool box, literally.



Tools in custom cut foam insert? Nope. Styrofoam peanuts.



Oh. Now I see why the box is so big. Room to store the FCABs.

[jdoublehcubed]

Originally Posted by StickMon

I just started getting some light shimmy under high speed braking, so I figure it's time to put on the FCABs I've had sitting in the drawer for months.
Either that, or the ECS rotors have gone out of true after only 6500 miles.
I figured it was worth getting the BavAuto/Koch tools, rather than try it with my crappy old puller.
They arrived tonight, in a box twice as big and heavy as expected.
Inside the BavAuto box was a Koch Tools box.
Inside the Koch Tools box was a tool box, literally.

Stay the fuck away from those ECS rotors. I'm on my second set, and they're completely out already, have to call and fight with ECS again.

Biggest part buying mistake I've ever made, buying this shit.

[StickMon]

Yea, that's what I suspect.

[ZStig]

my front tires have some cupping deformations from my alignment. -1.5* camber, 0 toe.

Every other tread block is slightly shorter or taller than the one before

[Shipkiller]

I would not suspect your camber. Something else is causing the cupping.

I ran with -2.5 camber in the front for two years with no issues. When I went to -3.1 thing got interesting.. where I corded the inside inch of a perfectly good set of tires. I did not have this issue at -2.5. I think somewhere around -2.7 is a tipping point for diminishing returns for a street driven car with occasional track time.