Steering Wheel Vibration

[dlhjimmy]

My car has a random/intermittent steering wheel shake at all speeds north of 50 mph. It's not affected by bumps or grades. The steering wheel also randomly shakes under braking about 50% of the time. Sometimes I'll have to stop quickly for a deer and the steering wheel stays rock steady, and other times it's shaking quite a bit.

Pads and rotors are new (properly bed in as well.) Tires are new and properly balanced (rotating tires doesn't change anything.) I've replaced the shocks/shock mounts, control arm bushings and ball joints, and sway bar links. I've also been very delicate and precise with wheel lug torques as I know it could contribute to the issue. Tie rods have zero play.

My best guess is maybe a sticking caliper or wheel bearings, but perhaps it's something I have yet to even consider.


I've done a lot of searching on this and realize there are a multitude of posts on similar issues, but I'd really appreciate any help/wisdom that's out there.

[Pelican Parts]

It sounds like you pretty much went through the usual suspects - wheel bearing would also be my last guess for this issue. Other members will likely chime in. If you solve this mystery, please update us; I'm really curious now what the outcome will be.

[dlhjimmy]

Will do, I'm sure we'll figure it out eventually.

[BMWManiac]

Seems to be common with these cars....steering wheel is very sensitive to vibration and shimmys. For your brakes causing it sometimes, I would still look at your calipers and make sure you are keeping up with fluid flushes every 2 years. For all else, I think the wheel bearings would make more of a grinding noises or issue when turning. Hopefully, you didn't use any URO parts for the suspension. You didn't mention sway bar bushings, just the end links.

As mentioned, keep us posted.

[dlhjimmy]

No URO parts were used. Sway bar bushings were not replaced but are not cracking and seem solid, however would be a simple fix of that was the issue. I have not flushed the fluid. Maybe I'll rebuild the front calipers and put in new fluid.

[TostitoBandito]

Have you had an alignment recently? All it takes is for there to be a bit of a mismatch in toe or something like that, and this can happen. Could also be the steering rack itself, even if the tie rod ends are in good shape.

Wheel bearings usually have different symptoms. You can typically isolate a bad front bearing by doing hard full lock turns in a parking lot. The outside wheel will usually groan if it's got a bad bearing.

[dlhjimmy]

Had an alignment earlier this year all is good with that. Rack is a Z3 unit the PO installed and appears to be brand new and properly installed. This weekend I'll do some more digging/testing, and update with any useful findings.

[notMpowered]

Sticking caliper was the issue on my car. Exact symptoms.

[dlhjimmy]

Checked out the calipers yesterday. The right side caliper looks like a seal is popping out around the piston. Thoughts?
20170902_132218.jpg

[LockDots]

Clean it and push it back in. If it stays great, if not rebuild or replace it.

[dlhjimmy]

Thanks for the feedback. Any recommended brands for new calipers? I see ECS tuning has new Bremmen calipers for $80 per side, seems like a solid price.

[TostitoBandito]

Don't buy new calipers unless you want to drop the $$$ for genuine BMW. Either buy rebuilt ATE/Centric calipers from ECS/Turner, or buy the ATE rebuild kits (just the o-ring and boot) and rebuild them yourself. The rebuild isn't that difficult to do, even for a novice:

1. Remove all your calipers and plug or clamp your brake lines to prevent brake fluid from going everywhere. Only clamp them if you plan on replacing the lines (good time to do steel lines).
2. Pop all the caliper pistons out with an air compressor using a black of wood to prevent it from becoming a projectile.
3. Remove the old boots and O-rings from all calipers.
4. Scrub all your calipers clean with brake cleaner and wire brushes or scotch brite pads. Use brake cleaner and a soft cloth on the piston and piston bore since you don't want to scratch it.
5. Replace all guide pin bushings with new bushings, and replace any damaged guide pins as necessary.
6. Wet your new O-rings and boots in some clean brake fluid, and insert the O-rings. Put some brake caliper assembly lube (or brake fluid) on the piston/bore, slide the boot just barely onto the end of the piston that you're sticking into the caliper. Slide the piston just into the caliper evenly, and seat the lip on the boot into the caliper all the way around. Once it's seated, carefully slide the piston all the way in (you should be able to do this by hand) and the boot will pop into the by the end of the piston as you do.
7. Put the calipers back on the car, hook up your brake lines, and flush/bleed the brakes with new fluid to get all the air out of the lines.

[dlhjimmy]

Thanks much, looks like that's the route I'll be taking. I'll be sure to update on the issue once the rebuild is complete.

[maneal4]

Yes seized calipers can sometimes be rebuilt easily (emphasis on sometimes), but it's almost always cost/time effective to replace with rebuilt units. Ask me how I know... a new boot kit will not fix a rusted up piston or seized pins

[TostitoBandito]

Pistons are actually pretty cheap if you need to replace one for whatever reason. The caliper is only usually toast if the piston bore is damaged. The guide pins and bushings should be replaced during a rebuild anyways. It's true that you don't end up saving a ton of money over rebuilt calipers with the cost of the replacement parts, but you do get to keep your stock ATE calipers with the M logo and all that jazz and not get Centric copies.

[dlhjimmy]

Where can one purchase new pistons if I end up needing them?

[LockDots]

Bimmerworld and Amazon both carry them at a decent price.

[dlhjimmy]

Rebuilt both front calipers. No change in steering wheel shake/vibrations. Exact same symptoms. Any more ideas?

[dlhjimmy]

I'm going to pull my rotors today and see if I can see anything out of place. Will keep updating.

[CircuitMonster]

Had the same issue. Rotors were all "warped" even though they were pretty new. Have a shop check them to see. But I went through everything as well and it ended up being rotors

[TostitoBandito]

Did this only start after you put on the new rotors, or was it happening before? Rotors don't really "warp" but can accumulate uneven pad deposits at high temperatures. If the rotors themselves were faulty from the factory with excessive runout, this issue would've started right when you installed them. If it gradually started sometime after that, try cleaning them first with a scour pad and brake cleaner (or a cold set of track pads).

Also, if you're getting any of this vibration/shake while you're not on the brakes (and you've already verified you're not dragging a pad), then it's probably not the brakes. It's most likely something loose/broken in your steering system or front suspension.

[tsmith25]

Since you checked the brake stuff already, I would look at the control arm bushings next. They are one of the points that maintains the toe alignment. If they are going bad, they could easily cause a steering shimmy under the right braking/steering conditions.

[CircuitMonster]

Did this only start after you put on the new rotors, or was it happening before? Rotors don't really "warp" but can accumulate uneven pad deposits at high temperatures. If the rotors themselves were faulty from the factory with excessive runout, this issue would've started right when you installed them. If it gradually started sometime after that, try cleaning them first with a scour pad and brake cleaner (or a cold set of track pads).

Also, if you're getting any of this vibration/shake while you're not on the brakes (and you've already verified you're not dragging a pad), then it's probably not the brakes. It's most likely something loose/broken in your steering system or front suspension.

Mine ended up being rotors and it was doing it while not on the brakes and doing it randomly while driving. So it can happen

[dlhjimmy]

Put on different rotors. Braking shake is gone but the intermittent shake while driving over 50ish is still there.

[TostitoBandito]

Sounds like whatever is causing the shake at speed might also be causing your rotors to wear unevenly while braking, making them get worse over time.