Steering Wheel Jerk Under Braking

[mLuMaN83]

So I have just replaced the tie rods, control arms, and bushings in the front end and I also replaced the two front brake calipers due to the right side being sticky.

This issue has become intermittent. Sometimes, when braking quickly, I get a quick bump in the steering wheel. The wheel will slightly jerk to the left or right. I also noticed a little wobbly sensation in the steering wheel for a very short moment doing around 35mph not under any braking.

I feel like this must have something to do with the brakes. I replaced both front calipers and bleed the entire system a few weeks ago and I have noticed these symptoms the past week.

- Warped rotor on the side where I had the sticky caliper?
- Air in the line?
- One caliper grabbing before the other?

Thoughts?

[Newjack]

So I have just replaced the tie rods, control arms, and bushings in the front end and I also replaced the two front brake calipers due to the right side being sticky.

This issue has become intermittent. Sometimes, when braking quickly, I get a quick bump in the steering wheel. The wheel will slightly jerk to the left or right. I also noticed a little wobbly sensation in the steering wheel for a very short moment doing around 35mph not under any braking.

I feel like this must have something to do with the brakes. I replaced both front calipers and bleed the entire system a few weeks ago and I have noticed these symptoms the past week.

- Warped rotor on the side where I had the sticky caliper?
- Air in the line?
- One caliper grabbing before the other?

Thoughts?

Could be a warped rotor. It could be your steering guibo. It could be uneven road surfaces where you are braking.

Its not air in the lines.

[mLuMaN83]

I don't think it's the roads. It is new and feels like a mechanical fault. It's odd because it seems to have started after doing the brakes. It may have still been there and didn't notice it due to the wore out front end parts. Maybe I feel it more now that the front end is firmed up.

Guibo... I'll look into that.

[derbo]

Double check if your lugnuts are tight. It could be a wobble too? Just a thought.

[mLuMaN83]

Yeah I thought about that while I was driving home today, I doubt it, but I will check tomorrow. I put the moves on those things with the lug wrench lol.

It's gotta be either that sticky caliper warped the rotor or the guibo. Those sound like the best places to start, but who knows, maybe something is loose in the suspension stuff I had replaced.

Another thing to note is that in the morning sometimes when the car is cold and has been sitting, I can feel a bumping sensation that changes with speed. It's most noticeable in first and second gear at low speeds. After a little driving, I don't feel it anymore. This could be related...

[LivesNearCostco]

That sounds like temporary flatspotting on the tires. I once had tires that did that, but don't remember which ones they were (maybe Bridgestone Potenza RE-760?). If that's the case, can either live with it or try higher air pressures.


Another thing to note is that in the morning sometimes when the car is cold and has been sitting, I can feel a bumping sensation that changes with speed. It's most noticeable in first and second gear at low speeds. After a little driving, I don't feel it anymore. This could be related...

[mLuMaN83]

That sounds like temporary flatspotting on the tires. I once had tires that did that, but don't remember which ones they were (maybe Bridgestone Potenza RE-760?). If that's the case, can either live with it or try higher air pressures.

I only feel it while in gear rolling without deceleration or execration. I don't feel it while rolling in neutral. Forgot to mention that.

[derbo]

Brake deposits on the rotor may affect this. I have a similar issue sometimes when I wash the car and don't drive it and the water seeps in between the rotor and pad to make an imprint.

[Avetiso]

Mike, I think you need to drive a track or performance car to get a feel for what hardcore road connection feels like. I drove my friend's M3 and I gotta tell you, you need to focus when you drive that car. Everything is fine, but it's constantly jerking as a result of road conditions.

Now, far as what's wrong with your car, I doubt it's your steering guibo. The jerk is coming from your wheels, and even if it was new, you'd still feel it, it'd just be less sudden because there would be no delay in the jerk. How's your alignment?

[mLuMaN83]

Mike, I think you need to drive a track or performance car to get a feel for what hardcore road connection feels like. I drove my friend's M3 and I gotta tell you, you need to focus when you drive that car. Everything is fine, but it's constantly jerking as a result of road conditions.

Now, far as what's wrong with your car, I doubt it's your steering guibo. The jerk is coming from your wheels, and even if it was new, you'd still feel it, it'd just be less sudden because there would be no delay in the jerk. How's your alignment?

It's more as if there is play somewhere or something is loose, thats what it feels like. All I know is that I had the front end stuff done and right after that, replaced the front calipers and bleed the system. I have not had a chance to get an alignment done yet.

Here's a video...


http://www.youtube.com/watch?v=BQOc-OygPw8

[3ZHP]

It's a common symptom of front control arm bushings and or Ball Joints. Mine did it for months before I changed the arms and bushings with new OE ones.


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[derbo]

It's more as if there is play somewhere or something is loose, thats what it feels like. All I know is that I had the front end stuff done and right after that, replaced the front calipers and bleed the system. I have not had a chance to get an alignment done yet.

Here's a video...


http://www.youtube.com/watch?v=BQOc-OygPw8

This happened when I had bad thrust rod bushings (FCAB). I replaced them and I no longer have this issue but if you said you already replaced all the pieces in the front end, this confuses me. Did you do inner and outer tie rods?

[mLuMaN83]

This happened when I had bad thrust rod bushings (FCAB). I replaced them and I no longer have this issue but if you said you already replaced all the pieces in the front end, this confuses me. Did you do inner and outer tie rods?

Here is what I had done.

http://www.fcpeuro.com/products/bmw-control-arm-kit-8-piece-e46-oem-e46cakitl

I'm kinda stumped too. I don't think I noticed this until I did the front calipers but I could be wrong. It seems suspension related more than anything...

[slater]

definitely looks like a bad FCAB - i have experienced that same phenomenon. seems odd to have that happen after new ones were installed (and lemfoerder, no less), but it could be a bad FCAB i supposed (or perhaps was damaged upon install).

an alignment is a must too, especially after replacing tie rods.

peter

[mLuMaN83]

So what should I look for in a "new" bushing thats failed?

There is a BMW specialty shop here in town that does really great work and the prices are right. I might just take it in and have them take a look then go from there. Not sure when I can get in because they are usually booked solid. I called about an alignment and they said around 3 weeks out lol. I'll give them a call and schedule an alignment per check of the new front end parts for any faults. I hope it's just something that needs tightening or maybe just needs alignment but I doubt the alignment will fix this. If not, The dudes who did the install/FCP euro will be getting a call.

It's funny, the work I do myself seems to go without hiccup and as soon as I let somebody else touch my car, theres a problem. I know my way around a bit and I'm not afraid to get some bloody knuckles, but I am no mechanic...

[Simmsled]

A proper alignment will solve this...
You have unequal toe, and when you apply the brakes (force), the steering corrects itself when the tires attempt to equalize the applied force. Because the left and right tires have different contact profiles (difference in coefficient of friction) one will grip more than the other and cause it to pull.

[derbo]

Wait, alignment was never done?

[mLuMaN83]

Alignment not done yet. The guys I wanted to do it have been booked for weeks.

I should have it in in the next week or two.

[mLuMaN83]

I just got off the phone with the BMW Specialty shop here in town, they said alignment should not do this and it must be a bushing.

I have the car scheduled to be looked at on the 17th.

[derbo]

I just got off the phone with the BMW Specialty shop here in town, they said alignment should not do this and it must be a bushing.

I have the car scheduled to be looked at on the 17th.

I agree. Alignment should not cause a judder during braking.

[Simmsled]

Still needs an alignment... regardless.

[llll1l1ll]

Get an alignment and have the control arm bushings examined. That was my issue when I had the jerky wheel on braking.