Bad shimmy around 45-50MPH front rotors replaced recently

[Xproplayer]

Hey guys,

I have a bad shimmy around 45-50 that only happens when braking, I just had what I believed to be warped front rotors as I was having a shimmy at all speeds, I had the rotors replaced and now the shimmy is back to where it used to be which is between 45-50, although its gotten worse with time. Could it be my rear rotors got warped as well? I am not sure how rear rotors could affect front wheel movement, as well I want to make sure there isn't simple fixes, I am going to take the car into a shop soon to have the tires rotated but last time I asked a shop they couldn't see anything, although the issue is much worse now would that help them diagnose under their generic free diagnosis?

[cazal740i]

How is your Brake feel? Same as before or do you see yourself pressing deeper to brake? Reason why I asked is if your brake system isn't fully bled the brakes , when pressed at 60mph and below,will cause a shimmy like feel... Have system bled again till theres zero air in system...Theres a bedding process for the rotors..Was this done correctly?
How are you traction control arms? When the Traction control arm`s ( Black Curved suspension arm) Bushing end goes bad go bad the wheel DOES NOT STAY CENTERED when braking.. The wheel will actually travel to right, on driver side) or Left( passenger side)

[Xproplayer]

How is your Brake feel? Same as before or do you see yourself pressing deeper to brake? Reason why I asked is if your brake system isn't fully bled the brakes , when pressed at 60mph and below,will cause a shimmy like feel... Have system bled again till theres zero air in system...Theres a bedding process for the rotors..Was this done correctly?
How are you traction control arms? When the Traction control arm`s ( Black Curved suspension arm) Bushing end goes bad go bad the wheel DOES NOT STAY CENTERED when braking.. The wheel will actually travel to right, on driver side) or Left( passenger side)

Forgot to mention in my original post, the brakes used to feel like they were warped in that when I was rolling to a stop it felt like it was gaining and losing grip, after the rotors were changed that went away. As for brake system it has not been serviced in at least 3 years or more, and the feel of the brakes is something I wouldn't be able to notice a change after all that time. For the arms and suspension components if you give me a picture or something I can look at it but all components are stock. 97 with 134k miles

[cazal740i]

Well goto a empty parking lot and have ur friend drive ur 7 at 5 mph and hit the brakes. If u see ur front wheel move from center spot then your traction arms are shot. They should stay center in the wheel well arch when braking
You will see the difference right of the bat when brakes r pressed with good and bad traction arms


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[cazal740i]

Forgot to mention when ur friend is in the car driving and hitting the brakes your outside staring at your front wheel. Try videoing it

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[Frankie]

I have a bad shimmy...I had the rotors replaced and now the shimmy is back...

You have bad brake rotors. I just went thru this. See this thread (especially post #19).

You probably installed non-OEM rotors because you wanted to save money. That's what I did. But never again.

[Xproplayer]

You have bad brake rotors. I just went thru this. See this thread (especially post #19).

You probably installed non-OEM rotors because you wanted to save money. That's what I did. But never again.

My brake rotors aren't OEM, I had just moved and was having a terrible shimmy at all speeds, talked with a mechanic who was at a shop with great reviews (4.5+ stars 80+ reviews) and they said the non OEM rotors would be fine, the issue was solved at first but now its come back during these speeds, that was like $400 already, you think I might have to spend another $600 to get OEM rotors installed?

[XAlt]

Get a good brand, Zimmerman, Brembo, etc.

Always ask for the brand.

[Chris V]

Sounds like the imfamous 50mph shimmy. In my last E38, my 50 mph braking shimmy was the torque thrust bushings in the upper front control arms (traction strut).

https://www.oembimmerparts.com/BMW-F...721-722e38.htm

[drinkingsnake]

Perhaps , like me ....

When i purchase my 740I, i've experience this " 50/60 mph shimmy", and , after discuss with an indy, i decide to flush and bleed my brake, and change rotor and pads for EBC products ....

Very quickly, the shimmy reappears , like before, but less violent, and i decide to change all my front end ( control arm, tie rod , sway bar link...etc...)

So, in your case, i manage to :

-1 Bleed and flush the brake
-2 good wheel balancing
-3 replace whole control arm, and more efficient, all the front end components, wich is a simple DIY


It's what I' ve done for my E38, and it works,

Cheers,
Chris

[funfunfer]

It's upper control arm bushings. It's always UCAs if the shimmy is still there after rotor replacement.
This is an easy DIY, but don't skimp on the quality of your replacement arms and make sure that you've checked all of the other suspension/steering bits.

[jazigk]

It's upper control arm bushings. It's always UCAs if the shimmy is still there after rotor replacement.
This is an easy DIY, but don't skimp on the quality of your replacement arms and make sure that you've checked all of the other suspension/steering bits.

Mine was a wheel balance issue coupled with dead shocks. The wheels out of balance 20g~25g, shook the steering because the shocks were unable to absorb the vibration. Increased tyre pressure improved the situation, rebalance to 0g-0g fixed it and now only leaves the usual dead shock symptoms.
I dropped my arms only to see near new Meyle HD arms and bushes in there. Everything under there looks new and no movement anywhere. After googling it, turns out the Meyle shocks are pretty shit quality anyway.

The arms are a easy DIY job anyway so won't hurt to check them by dropping them. 15 minutes to have the car jacked up and the arms drooped down at the bush end.

[sealbeach740]

you think I might have to spend another $600 to get OEM rotors installed?

$600 to just replace rotors?
I suggest you shop around a bit & maybe find an indy that doesn't charge so much.

[Xproplayer]

$600 to just replace rotors?
I suggest you shop around a bit & maybe find an indy that doesn't charge so much.

I was billed $400 for non oem and they said if I needed oem itd be 500-600, but the guy assured me he has compared the two and noticed no difference, I trusted him given the shops public ratings.

[Frankie]

...I might have to spend another $600 to get OEM rotors installed?

Yep, you need OEM rotors for sure based on your story (vibration AFTER replacing; only when braking). And don't listen to those saying your problem is thrust arm bushings. It's not.

As for price: if you're handy, simply buy rotors from a discount online dealership and install 'em yourself: $109 each. There are many DIY's online. It's not difficult.

[Chris V]

Yep, you need OEM rotors for sure based on your story (vibration AFTER replacing; only when braking). And don't listen to those saying your problem is thrust arm bushings. It's not.

if it's rotors, it won't happen only at 45-50 mph, It'll happen all the way to a stop and also from higher speeds. They don't "unwarp" magically at 40 mph.

The 50 mph shimmy under decel is a known issue with E38s and a known repair.

[Xproplayer]

if it's rotors, it won't happen only at 45-50 mph, It'll happen all the way to a stop and also from higher speeds. They don't "unwarp" magically at 40 mph.

The 50 mph shimmy under decel is a known issue with E38s and a known repair.

Yea I had the issue before where it felt like it had a wider range that it was shaking, now it feels limited to those speeds but is more harsh. Can rotors not be tested by some machine, during all my diagnosis it seemed like it wasnt a thing?

[Frankie]

...it felt like it had a wider range [of] shaking, now it feels limited to those speeds but is more harsh. Can rotors not be tested...?

You're in denial. I've been there.

Yes, some symptoms don't make sense. Consider: if it's bad thrust bushings, the shake would occur under conditions other than just braking. I spent $$ on exotic aftermarket bushings (Rogue Engineering). They did nothing for my shake. (Well, they did make it more pleasant.) You're probably getting some front tire wear too (feathering), aren't you?

And yes, rotors can be tested (turned) by any brake shop, for cheap. But it'll come back. Brake parts other than OEM can really suck -- I don't know why.

Do what you feel is right. This will be my last attempt to persuade you. In my experience, you're wasting your time AND money if you think brake shake is anything other than crap-tastic rotors.

[Xproplayer]

I've been trying to further diagnose the symptoms and one thing I have noticed is that I will get vibration when not braking, it causes the steering wheel to rotate about 1 inch left and right at most, compared to when braking it could be 2-3(?) still trying to get the car taken in for a typical rotation and tell them to poke around in the various parts mentioned here.

[XAlt]

Just throw new rotors and bushings at it and call it a day. It's time for new suspension bits anyways.

[racer2086]

It is probably your thrust arm bushings if it shakes going down the road without braking, but if the warping is severe enough, it can cause the shake.

[Xproplayer]

Been a long time since I last posted here since I lost my job end of January and haven't driven the car much at all until the past few weeks when I got picked back up. So basically right now I get a shake when not braking around 50mph, but it's probably less than half an inch, then when braking it is harsh, I have to hit the brakes much harder to stop it from getting very violent on me as it feels like the car will shake itself apart. It's a frustrating issue since everyone has a different opinion. I want to attempt to check as much stuff myself, I want to believe it's not the rotors since the issue has always been in the car but only got bad in the past year (had it for 2-4 years?) and when I replaced the rotors the issue was gone very quickly but returned (though maybe shitty rotors just got warped?) Long story short I want to do things DIY as well since the Indy shop I went to may have been the cause of the issue by assuring me the non oem rotors were fine. In the end is there any other test I can do besides the parking lot slow braking that was recommended?

[Chris V]

Gonna say it again. Thrust arm bushings. Especially if it's there when NOT braking at 50 as well. Do a search on 50 mph shimmy here and on bimmerboard. It's very common, and happens to a lot of E38s.

http://www.bimmerboard.com/forums/posts/692106

http://www.bimmerboard.com/forums/posts/1230642

[clarkitect]

I have the brake shimmy and vibration at higher speeds despite replacing all suspension and brake components. And despite much searching. Pretty frustrating. Did not use OEM brake rotors, used the BrakeMotive product that others have used presumably with success. I think maybe the Meyle HD thrust arms are not that HD.

[Xproplayer]

Any way to self diagnose any of the possible failed components at home?