Steering shake at highway speeds on initial brake application

[theLedger]

At highway speeds when I first apply the brakes, I get quite a bit of steering wheel shake and can feel it it somewhat in the brake pedal. As I press the brakes harder the shaking goes away. Around town, I don't really feel anything at all, light or heavy braking.

It's as if the front wheels are loose and with heavy braking, they tighten up.

I jacked up the front end and with my hands at 12 and 6, I can't move the front wheel. At 9 and 3, I can move the front wheels maybe 1mm.

I just replaced all 4 wheels with Zimmerman rotors and Textar pads and also both front wheel bearings. Wheels spin nicely and rotors look great upon visual inspection.

Does this sound like I need new tie rods because perhaps the bushings might be worn? I couldn't move anything with my hands in the suspension.

- - - Updated - - -

Shop called back again and confirmed that it is the front rotors and they suggested that they should be under warranty. The front end suspension is tight (which is good news). This seems weird to me but I'm replacing the Zimmerman rotors under warranty (thank you Pelican Parts). On rare occasions, even the best made parts can be defective.

[retiredat44]

are you sure it isn't the control arms worn bushings? that's what happens with the BMW when the bushing wear and you have to replace the whole upper control arms.

[David GEO]

All the symptoms you wrote down, must be a rotors issue.

Happy for you.

Sent from HTC 5.5' Desire 816 dual sim, using BMW forum app for Android

[dimeitry]

Really sounds like a warping rotor.

[pbonsalb]

My vote is for the front suspension bushings. They are a problem on these cars as they age; did them on our 08 535xit at around 75k miles. I think they call the arms strut rods or stays -- they are the ones going forward from the spindle area. The bushings are relatively cheap. Hit the brakes and worn bushings allow excess movement and feel just like a warped rotor.

[silverfbimmer]

I had a similar issue...it was the bushings.

[theLedger]

It was the rotors and they have developed a slight warping again. I just replaced the thrust arm with new bushings and don't really feel it anymore.


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[jclausen]

Aftermarket brake parts, get rid of warped rotors by using genuine factory brake pads and rotors, yes they are expensive but you won't be doing the job twice, loosing money and in beating up the front thrust rod bushings

[theLedger]

The replacement Zimmerman rotors warped again but I took it out yesterday and performed some brake bedding (drive up to about 60 mph and then brake hard to slow to a crawl and repeat) and that seemed to cure a lot of the vibration when slowing from highway speeds. Eventually I will have to replace them again and next time, they will be genuine BMW pads and rotors. The original rotors never warped even when they were nearly gone.

[oclvframe]

The replacement Zimmerman rotors warped again but I took it out yesterday and performed some brake bedding (drive up to about 60 mph and then brake hard to slow to a crawl and repeat) and that seemed to cure a lot of the vibration when slowing from highway speeds. Eventually I will have to replace them again and next time, they will be genuine BMW pads and rotors. The original rotors never warped even when they were nearly gone.

Rotor hot spots are often confused with warped rotors. The whole process of bedding in brakes as you did is to evenly transfer pad material to the rotor. Hot spots occur when pads are clamped down on the rotor and the rotor is really hot. Its like leaving a hot iron in one spot and burning a shirt.

When I replaced rotors and pads, I went with Centric rotors and once bedded in (it took two different sessions) they've been flawless since. Only thing I wish I had done different, though, is gone with Akebono Euro Ceramic pads....the centric pads I went with still dust a good bit although no where near as bad as stock.

I would venture to guess that after your current round of bedding, you'll be fine.

-r

[theLedger]

The vibration came back and I tried the bedding process again but the fix was only temporary.

Next time I'm buying genuine BMW pads and rotors. They cost more but they go the distance.


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