Steering Wheel Twitch When Braking

[llll1l1ll]

Hi All,

Just got my ZHP the other day. So far so good. I'm just curious as to what this symptom could be telling me.

Periodically, I'll apply the brakes and the steering wheel twitches just a little bit. It's noticeable but not a nuisance. It seems to be happening when I apply the brakes more aggressively, or when the car thinks I am applying the brakes more aggressively. If I am really soft, it won't do it, but I've caught it happening when it's soft.

The car does not try to change direction, pull to the left or right, or anything like that. There is no vibration when braking from high or low speeds. No noises. Just this small twitch. Is this part of the DSC/controlled braking/some sort of computerized safety thing? I'm new to the world of these systems, haha.

Sorry if this thread has already been created somewhere else. I did my due diligence, but I couldn't find anything.

Thanks!
Peter

[Oli77]

Could be nothing.

You mention this happens periodically, is it happening on a particular street where the pavement may be causing some tramlining? I remember being concerned when I first got my e46. These cars will hug the road (contours, imperfections, etc..) and in some places in town will shift left or right when braking.

Off course, you should make sure you don't have a failing brake cylinder.

[llll1l1ll]

The car does tram but that's not related to braking. The only thing I could think of is that one caliper is gripping just before the other. I have not noticed any sticking caliper symptoms or anything else like that.

[danewilson77]

You probably have NOT had time to inspect the brake pads/rotors/fluid levels?

If rotors are good....maybe fresh pads and a fluid flush would clear up this nuisance. Maybe there is a lil air in the system? Cheapest way to go may be...just do a quick bleed...and see what happens.

[llll1l1ll]

Yeah I haven't had time to really get a good peek at the car. I don't have a good set of ramps at my place and I think my jack is too big to fit under the car.

Like I said, it's not that much of a nuisance - I was really more curious.

[aurelius]

A hundred bucks on mildly warped front brake rotors.

[llll1l1ll]

Hahah the brakes are a couple years old according to the service records. I'll probably have a go at them towards fall.

[johnrando]

A hundred bucks on mildly warped front brake rotors.
+1

[static667]

I'm going with putter tie rod ends. I had this issue with one of my e36s. I did a complete brake job and it still persisted. Changed the tie rod ends, problem solved.

Sent from my SCH-I500 using Tapatalk

[danewilson77]

Ahhh....yeah...tie rod ends would dhu eeet.

[Jorge86]

I have the same issue. But the brakes are brand new with oem pads and rotors. the problem was there before the brake job and it's still there. I have checked the whole suspension and I can not find the problem. I have brand new zhp struts -- front and rear -- and it's still there. Just a little pull to the left when I brake at high speeds.

[rikdee]

I have the same issue. But the brakes are brand new with oem pads and rotors. the problem was there before the brake job and it's still there. I have checked the whole suspension and I can not find the problem. I have brand new zhp struts -- front and rear -- and it's still there. Just a little pull to the left when I brake at high speeds.

Tires are always in play at such subtle levels of investigation.

[johnnyrad]

Front control arm bushings. I had the same twitchy thing going on also but after installing the Powerflex fcab's everything is wonderful! Man I sound like an infomercial.

[echo46]

Plus one for johnnyrad. My guess is control arm bushings. I have the same symptom. I will be changing the control arm bushings this weekend so I will report back with my results. I using the Meyle HDs.

[johnnyrad]

And if they look like this, then you made a wise choice in changing them

http://i1092.photobucket.com/albums/i401/bslotterbach/DSC_0860.jpg

[lilcdkey]

A hundred bucks on mildly warped front brake rotors.

+2. Any uneven wear could cause it.

MOTOROLA ATRIX TAPATALK

[kayger12]

My money is on CABs.

Droid X. Tapatalk. Use it.

[Jorge86]

Brand new cab as well in my car. I have checked everything but did not really find anything. But I have not really really checked it out. It's not annoying that bad if u know that It might happen. And it only does it once on a while at high speeds. I know there is something wrong and eventually I'll find it.

[llll1l1ll]

I'm gonna watch this thread like a hawk. Records indicate that the CABs have not been replaced in a while, so it might actually be them.

[johnnyrad]

I'm gonna watch this thread like a hawk. Records indicate that the CABs have not been replaced in a while, so it might actually be them.

If I remember correctly, the way to tell if you need cab's, just grab your front tires at 3 and 9 o'clock while the car is on the ground and push and pull back and forth and you will feel the "play". The tires will move noticeably back and forth if they need changing because the bushing isn't holding the control arm snug in place. I'm not a mechanic but if your car has over 40k and you have the steering wheel "shutter" when you hit the brakes and your not sure if the cab's have been replaced it's a good idea just to do it. Just make sure you get an alignment after you change them.

[Oli77]

My symptoms were a loud clunk in the front upon first applying the brakes (would not do it always). Sharp, metal on metal. One side only. I could not feel it in the steering wheel but towards the end, I could feel it in the brake pedal.

Anyway, i tried that trick above and my little French arms (not really qualified as "guns") and could not make the wheel move at all, so I thought it was something else.

Then I had the one CAB changed and bingo, noise gone.

I guess you have to torque on that wheel pretty hard to make it move. I think having a buddy standing outside the car and observing your tires while you drive at 1-2 mph could tell if the wheel move towards the back of the car slightly when you hit the brakes.

[llll1l1ll]

Well, I was at a shop yesterday and they recommended I have the CABs changed as there was some play in the wheel. I'll take care of that in a few weeks.

[llll1l1ll]

Front control arm bushings. I had the same twitchy thing going on also but after installing the Powerflex fcab's everything is wonderful! Man I sound like an infomercial.

Ning ning ning ning ning we have a winnarr!

I had to get the CABs replaced for MD State Safety Inspection. I had them put on the Meyle HD CABs. Car rides a lot smoother, but the twitch is gone. I hope it doesn't come back.

[Rovert]

Warped Brake Rotors = Steering wheel wobble upon braking that increases with speed.

Worn out Front Control Arm bushings = Steering wheel wobble upon braking & Twitch in steering wheel upon quick brake inputs.

Worn out Front Sway Bar End Links = Steering wheel wobble upon braking & Twitch in steering wheel upon quick brake inputs & rattling when going over bumps.

I've experienced all of those conditions I have mentioned.

[Audi 0000]

I see others have suggested this, but my newly aquired zhp would do the same. On initial braking wheel would snap to right, less noticable at higher speeds. I had it on a lift at work and the front control arm bushings had play. Installed new ones and problem solved.

[AutoXfreak]

Front control arm bushings. I had the same twitchy thing going on also but after installing the Powerflex fcab's everything is wonderful! Man I sound like an infomercial.

+1, the fluid filled bushings get soft over time. Usually on a hot day when the pavement temps are high this may be even more pronounced than if the pavement were cooler. Usually you can feel the wheel tug your hands.

I would replace your front control arm bushings.

[Marcus-SanDiego]

^^ Welcome to the forum. Thanks for chiming in. Another tech guy. Nice.

Be sure to introduce yourself in the new members forum. Looking forward to seeing you on the forum.

[edlvrt]

I have a similar quick twitch to the right but no sustained pull when I quickly stab the brakes. FYI, my control CABs are 2000 miles old, but the control arms and tie rods are original at 75k miles. Pads and rotors were changed ~15k miles ago. I thought of something yesterday that may be associated, but I don't know if our E46s have this feature....

I remember hearing in BMW's literature that the braking system will pre-load the brakes when it detects a possible panic stop, ie, when you lift off the throttle fast and quickly get on the brakes. Perhaps the electronics are applying a little bit more pressure/a little faster to one side than the other and this is what give the twitch, as I don't experience it under normal breaking conditions. Again, I'm not sure that E46s have this feature, but it sounds plausible in my non expert opinion.:dunno