[buylongterm]

So I took my car into the dealership because while breaking (around 60mph) the car shakes uncontrollably. They came back and said I have 3 severely bent RIMS and I need to buy 3 new ones. I then spoke with a well known wheel place and they told me they can definitely straighten and balance the RIMS, but even bent rims should not shake a car that bad.

I then called BMW back and told them what the wheel guy said and they told me (with an attitude) "We definitely checked everything out, and are confident it's the RIMS". So over the weekend, I got the RIMS straightened (2 front) and all 4 balanced. Still have the issue. SHOCKER!

Any suggestions as to whats wrong?

I'm pissed, and obviously going back to the dealership, but I have to travel this week and curious if the car is even safe to drive? (Probably too hard to speculate)

[1chanc3]

sucks that you have had such a hard time.

When I told my SA that my steering wheel was shaking when i pressed the brakes on the freeway, he immediately put in a request to have my brake pads changed. Granted I was still under 40k warranty and nothing was charged to me.

The shaking went away after service. Hope that helps.

[AtlantaDude]

Yeah.. if it's shaking while braking, it's got to do with the braking system. Pads and rotors. That would be fix number one. If it was the wheels, the car would always shake. Depending on how many miles you have, it may be a good idea to have the calipers re-built. Rebuild kits are pretty cheap, and if you're worth anything with tools, it's easy to do yourself.

If you do all that, and still get the shake, then I would start with bushings after that. It may be a bad bushing (or 4) that's allowing the wheel to move in the wheel well.

[carlsontheflyer]

I had the same issue. I would feel vibrations through the steering wheel when braking aggressively from higher speeds. I thought it was due to a problem with brakes, but those were fine. The problem ended up being a control arm bushing on one side was completely shot. It was so bad, the gel leaked out from inside. Installed 2 brand new Meyle HD bushings and everything is smooth as silk.

[foghat]

Most likely the front rotors. My steering wheel was shaking on brake. Changed front rotors and pads, shake gone.

[buylongterm]

Thank you guys! That definitely helps, especially since I'm still under full warranty. (hopefully control arm/bearings are covered)

Here's the funny thing. When I took the car in, I checked my vehicle status. It said 1800 miles to replace front brake pads and 2K miles to replace rears.(they told me it was still to early to replace). However, when they returned my car, it said 48K to replace rears, and 43K to replace fronts.

I'm going to demand they replace brakes and rotors before warning light comes on.

[buylongterm]

Originally Posted by carlsontheflyer

I had the same issue. I would feel vibrations through the steering wheel when braking aggressively from higher speeds. I thought it was due to a problem with brakes, but those were fine. The problem ended up being a control arm bushing on one side was completely shot. It was so bad, the gel leaked out from inside. Installed 2 brand new Meyle HD bushings and everything is smooth as silk.

Interesting! Thank you. Would this be covered under BMW warranty?

Still waiting to get a call back from SA. been hours. Not a happy camper right now.

If it is control arm bushings, is the car safe to drive? I'm not sure I can schedule an appt. before I leave Thursday.

Btw, the car does shake mildly when driving, but not as bad as it did before they fixed my rims.

[carlsontheflyer]

Originally Posted by buylongterm

Interesting! Thank you. Would this be covered under BMW warranty?

Still waiting to get a call back from SA. been hours. Not a happy camper right now.

If it is control arm bushings, is the car safe to drive? I'm not sure I can schedule an appt. before I leave Thursday.

I am not sure if it's covered by the warranty. Mine ran out at the end of 2013, so I had to pay for this myself.

It *should* be safe enough to drive unless the bushings are so bad that they fell apart. Mine was pretty bad and it caused the whole suspension on that side to move back and forth about an inch, and that's was caused the vibrations under braking.

[GoRomeo]

Its probably due to warped rotors.

[BQTuning]

Rotars and brakes need replacing. Prime issue is the rotars

[Ph3n0m]

As stated above, if it's only happening under braking it's the brakes. Thats been my experience.

[grzes]

if your rims would be bend you would feel shaking just by driving and not during the breaking time. Rotors are more like a culprit. Over the time they do bend if you break aggressively a lot or if they get very hot and are cooled off suddenly. There is a reason why they do like to change them together with breaks, it seams like a waste of money but it does help.

[buylongterm]

Again, thanks everyone! I am going to demand them to replace brakes and rotors ASAP as well as double check the bearings. I will keep you updated.

Much appreciated!

[Lux3m35i]

Could be the rotors or bushings. The simplest thing is to check the rotors if the are wrapped. It could also be possible that the wheel bolts are not tightened properly and therefore the rotor is not sitting correctly on the wheel hub (we are talking of units around 0.01mm). Also dirt and corrosion between wheel hub and the rotor will lead that the run-out of the rotor will cause the vibrations.

Myself I had the same issue at the front rotors (they were brand new! after winter I noticed the vibrations). I measured a run-out of 0.04mm at the rotor. I disassembled the brakes/rotors and cleaned the wheel hub from corrosion and dirt. After reinstall (and tightening the rims properly with a torque key!) the vibrations are gone.

Measuring the run-out is not a difficult task and can be done with tools which costs you 30-50$. As I know BMW gives a tolerance of 0.05mm, but I cannot agree that..

[Tiago@VRSF]

Generally shaking while braking is caused from brake pad deposits caked onto the rotor from high speed braking on a soft/oem pad. Most shops only change $10 per rotor to "turn" them which essentially means they take off a small amount of material off the face of the rotor and that fixes most issues.

The shake will be significantly worse if you have any worn suspension bushings which in that case you'd need to replace the bushings first and if the problem persists, you'd look at the rotors.

[foghat]

^ ya, op could also try bedding his brake pads. That can help with deposits.

[JStang]

I'm having the same issue and I just replaced front pads and rotors a coupe of months ago. I suspect a bad control arm bushing and I am having them swapped out for M3 arms on Friday. I will check back in to let you know if this fixes my issue.

[JamesM3M5]

Originally Posted by Tiago@VRSF

Generally shaking while braking is caused from brake pad deposits caked onto the rotor from high speed braking on a soft/oem pad. Most shops only change $10 per rotor to "turn" them which essentially means they take off a small amount of material off the face of the rotor and that fixes most issues.

The shake will be significantly worse if you have any worn suspension bushings which in that case you'd need to replace the bushings first and if the problem persists, you'd look at the rotors.

I wouldn't recommend turning any BMW rotors, and BMW specifically states that you shall not.

But you're damn right about the bushings. This is the exact symptom of a bad Thrust Arm bushing, or Upper control arm bushing on the front. Pad deposits are the reason the brakes shudder, but the worn bushings magnify this significantly.

Avoid getting the brakes hot and coming to a stop with your foot firmly on the pedal. With an automatic, this is not easily done. It glues a microscopically thin layer of pad material to the hot rotor, and you can even see the imprint. This is somewhat normal, but just try to avoid doing it. The bad thrust arm bushings - or possibly worn balljoints or tie rods if your car has a lot of miles on it - are 99% certain the cause.

FYI - the E9x M3 thrust arm bushings are a direct press-in fitment. The thrust arms are identical, only the bushings are different between the M and non-M.

[SoCalHarley]

As an new BMW owner can someone please explain the technical reason for not turning a BMW rotor. I just did brakes and had the rears turned. Plenty of material and still way above min spec after being turned. Brakes perform perfectly.

[Tiago@VRSF]

Probably due to them being vented, but I'm guessing the overall reason is they can make more on rotors than they do for turning them.

I've done it a couple times on older 325's and 330's without issue. Just be careful of how much material is removed and you're ok although I haven't attempted it on a newer rotor.

I actually had pad deposit issues on our shop M3 and remedied it by installing a more aggressive race pad for a couple hundred miles. The aggressive pad essentially smooths the surface down since it's significantly more abrasive and you benefit from better stopping power. Just be careful which pad you go with as a more aggressive pad may lead to increased brake noise.

[V8bait]

Originally Posted by SoCalHarley

As an new BMW owner can someone please explain the technical reason for not turning a BMW rotor. I just did brakes and had the rears turned. Plenty of material and still way above min spec after being turned. Brakes perform perfectly.

Because race car. Or because $$. Or most likely because idiot service advisor.

On a serious note reasons not to turn would be a quality control/safety liability type policy not so much engineering unless you have special rotors like carbon.

Pad deposits happen. If you heat the rotors up a lot they can warp too. Then ya got yerself a bumpy stop pedal.

[SoCalHarley]

Thanks. So there is no real technical reason for not turning the BMW rotors. IMO they are no different than any other rotor. All the reasons or cautions turning a rotor apply but there is really nothing special about a BMW rotor from what I can see.