Kyle Kruchok

2009, 528xi, 103k mi.

I'm beyond stumped.

Highway speed, the steering wheel wobbles fairly aggressively, quickly. It's gotten a little better after replacing each of the parts listed below, but I'm still stumped as to why it's doing this. It's stupidly annoying because my pile of garbage Prius doesn't wobble, on the same roads - so I know it's the car. Happens whether or not I'm accelerating. Sometimes it gets more intense when I press the brakes, sometimes it goes away.

Fore, and aft lower control arms
Wheels
Tires (twice) (Road force balanced, each time)
Ball joints on both control arms.
Brake rotors / pads.

Any ideas what else I should be going for? CV shafts are like the only other thing that moves, that I can think of...

I'd love to have this thing figured out by the time summer comes around - I wanna take it on road trips if she's healthy! Otherwise... She'll sit.

NoQuarter

You did 4 control arms in total then? 2 each side?

Kyle Kruchok

That is correct! Just put on the aft arms last night, and didn't see a *HUGE* amount of wear on the inner part of the bushing (where it mounts to the subframe) - but just a couple very tiny cracks. Figured I had the parts, might as well throw 'em on.

It's better - but it's not quite right, yet. I'm wondering if it was 10 different things all at once (in very small affect), then all I need now is a rebalance / realignment to cinch it all up.

Pistratoaie

What tyres did you put on? On mine it start wobbling after I got Achilles ATR Sport2 put on, I was told it's the tyres being difficult to balance...Although mine's not that bad, so I put up with it.

NoQuarter

120,000 miles on 2008 535xi and I was getting steering wheel wobble cruising straight on the highway. Apply the brakes would cause a more severe wobble momentarily then it would smooth out as I slowed down.

I changed the 4 control arms and was prepared to do the inner and out tie rod ends, and ball joints.

My tie rods were in perfect shape and the ball joints were going to be very difficult to remove. I wanted to replace them because I had everything I needed but they were perfect. Since they were very hard to get out I just left them for a shop visit in a few more thousand miles if necessary.

Took care of my problem. I am back to smooth steering wheel.

A couple things come to mind that can contribute:

- HOW you mount the wheel to the hub is critical. If the first bolt is too tight then the other bolts may not tighten the wheel to sit properly against the hub. Mount the wheels with care and precision. Also make sure the hub surface and wheel surface have been cleaned. Add in some anti seize while you are at it on the face of the hub. Properly torque the bolts in small increments as you work around in a star pattern.

- The hub itself may not be true. You can use a runout gauge to check the hub. If it is not true then the wheel won't be either and the brakes will have a pulsing feeling as when people mistakenly call "warped" rotors. (We don't warp our rotors driving to work and the grocery store).

- Tie rods (inner and/or outer)


Jim

Kyle Kruchok

Thanks for the replies, all!

Pistratoaie - I've got some Mastercrafts... Not sure which model - but basically I didn't want to put the very top of the line tire on. I, however, made sure it wasn't the bottom of the barrel... if I wasn't sure it'd fix the problem. But after replacing everything I've got, it makes me wonder.

NoQuarter - The ball joints were already pressed into my control arms - all 4 of them - so I've got new ones in, all around. The ball joints looked / felt fine as they came out. The other 'hydrobearing' (bushing) just had some hairline cracks, and I was super happy to see those, thinking that the new arms would fix it. Boy was I wrong! I haven't done the tierods...inner, or outer, so I guess that's just on down the list. Do you think I should do those, before doing a higher end set of tires?

I always mount the wheel in a star pattern, and torque in that pattern as well. I never tighten one lug until I get all 5 sitting against the wheel. Good call on putting some antisieze on the mating surface as well - those can be a real beach to get off! How would a hub become un-true? And I assume I can just go to a shop to get that checked out?

Stumpel

If I read your original post correctly you changed the wheels? Are these hubcentric and correct for the car? I had a similar experience with older M5 wheels that I use for snow tires. After installing hubcentric rings, the wobble went away.

Kyle Kruchok

Yep - replaced the wheels with the exact same model as the ones that came on the car, from the factory.

As a minor update - maybe potential information leading to an answer - when I have a passenger in the car (girlfriend, of about 120lbs), the vibration is reduced by about half the intensity.

This leads me to think it's tire / suspension related, rather than wheel itself.