Steering Shake

[Hypnotist]

REVISED: Steering Shake

First some facts:
2006 GT manual
11000 miles
Bone stock
17" Std Wheels - original tires

Problem:
I developed a small shake in my steering at freeway (60mph+) speeds after rotating my tires. My initial thought was that my front left tire was out of balance. I got some curb rash on it when it was on the rear which apparently threw the weight off. The shake would be the a rhythmic 'wobble' of the steering wheel when held lightly.
Then a more violent shake showed up with medium/heavy braking. This was getting quite irritating.

Solution?:
Took it to the dealer. All warrantied work BTW. They ground my front rotors and balanced all my tires (only 2 were out of balance slightly). Everything seemed fine! I was happy. Except for I could NOT get the reason WHY this was happening from them... Why did my rotors need grinding? If they were warped somehow, how did they get that way?

But I chalk it up to my experience with mechanics who can fix a problem but not tell me what caused it.

EVERY tire was rebalanced, new weights on ALL of them, I can't beleive they would come loose.

Problem again:
Since I first posted this, the shake has gotten slightly worse. not as bad as originally, but seems to be on it's way. That's only been 800 miles and 2+ weeks!!

While changing my oil this weekend, I had the front wheels off the ground. I spun them by hand and noticed the brakes were rubbing on the rotor at one part per revolution (not all 360deg) - ON BOTH SIDES! As if the rotor were warped. Before the 'repair,' I would be able to spin the wheel easily and it would take a while to stop. Now the rotor rubs on the brakes and it will stop the wheel prematurely.

Help:
-SO:Were my rotors ground incorrectly? If so, WTF!!?? Have them ground again??? That should be done right the first time!!
-My next guess would have to be alignment or a bearing of some kind...
a. Has anyone experienced something like this with their car? Or am I experiencing an isolated incident?
b. Should I be wary of taking this back to the same dealer to get it 'fixed' yet again? Because they have been nothing but courteous to me.
c. Is there anyone who could maybe tell me what the problem might be? The dealer shop certainly couldn't.
d. Does anyone know of a GOOD small shop (with honest & helpful mechanics) in SE WI that would do warranty work?!

In General:
I paid WAY too much for this vehicle to have hassles like this, and am not willing to constantly waste my time returning to the dealer again and again for the same issues. But I guess if it's enough times, I'll just get a new one!

Thanks.

 

[05MGT]

Wheel bearin perhaps? Maybe the wheel weights are just coming off. Sometimes they dont put them on good enough.

 

[anthony05gt]

If you have 18's, it's common for them to not balance completely do to the lack of sidewall. I have 18's with Michelin pilot sport tires and had them road force balanced 4 times and I still have the exact issue you have. The road force machine had just been calibrated before my last visit to my buddy's shop. One of the more experienced mechanics there told me he sees that quite often. By the way, my steering wheel shimmy comes and goes.

 

[denck]

Shimmy here also, did you ever find the problem?

Hi,

I have been having the exact same shimmy problem you havebeen having on my 06 gt.. I had 20 inch bullets on it and it shimmied from 55-70 sometimes more than other times.. Went to 18 inch bullets and the shimmy was reduced but still there. Next up the dealer put on the origional 17 inchers, and the shimmy was greatly reduced, but could still feel it in the wheel.

They have no idea now what to try next.. The car came from the dealer with the 20's and a 1 inch drop with bilsteins and hypercoil springs.. I have had this problem since brand new.. I was thinking the geometry is off from the lowering and maybe a bumpsteer kit could correct the tie end rod angle back to stock, but not sure..

Did you ever find the problem? By the way, the clips everyone says to try are not on the studs...

Thanks a lot,
David

 

[07gtcs]

First some facts:
2006 GT manual
11000 miles
Bone stock
17" Std Wheels - original tires

Problem:
I developed a small shake in my steering at freeway (60mph+) speeds after rotating my tires. My initial thought was that my front left tire was out of balance. I got some curb rash on it when it was on the rear which apparently threw the weight off. The shake would be the a rhythmic 'wobble' of the steering wheel when held lightly.
Then a more violent shake showed up with medium/heavy braking. This was getting quite irritating.

Solution?:
Took it to the dealer. All warrantied work BTW. They ground my front rotors and balanced all my tires (only 2 were out of balance slightly). Everything seemed fine! I was happy. Except for I could NOT get the reason WHY this was happening from them... Why did my rotors need grinding? If they were warped somehow, how did they get that way?

But I chalk it up to my experience with mechanics who can fix a problem but not tell me what caused it.

EVERY tire was rebalanced, new weights on ALL of them, I can't beleive they would come loose.

Problem again:
Since I first posted this, the shake has gotten slightly worse. not as bad as originally, but seems to be on it's way. That's only been 800 miles and 2+ weeks!!

While changing my oil this weekend, I had the front wheels off the ground. I spun them by hand and noticed the brakes were rubbing on the rotor at one part per revolution (not all 360deg) - ON BOTH SIDES! As if the rotor were warped. Before the 'repair,' I would be able to spin the wheel easily and it would take a while to stop. Now the rotor rubs on the brakes and it will stop the wheel prematurely.

Help:
-SO:Were my rotors ground incorrectly? If so, WTF!!?? Have them ground again??? That should be done right the first time!!
-My next guess would have to be alignment or a bearing of some kind...
a. Has anyone experienced something like this with their car? Or am I experiencing an isolated incident?
b. Should I be wary of taking this back to the same dealer to get it 'fixed' yet again? Because they have been nothing but courteous to me.
c. Is there anyone who could maybe tell me what the problem might be? The dealer shop certainly couldn't.
d. Does anyone know of a GOOD small shop (with honest & helpful mechanics) in SE WI that would do warranty work?!

In General:
I paid WAY too much for this vehicle to have hassles like this, and am not willing to constantly waste my time returning to the dealer again and again for the same issues. But I guess if it's enough times, I'll just get a new one!

Thanks.

IMHO

If your rotors are warped, get new ones. turning them (grinding them) may not fix a warp rotor...turning the rotor is usually done to get rid of crystalizing or uneven surface. Besides, I find hard to believe that warped rotors will cause a shimmy while driving at 60 mph...you will notice if you have a warped while you step on the brakes. If they are warped you will notice a shimmy in your steering wheel while braking only. If you are having shimmy problems while moving, it has to be a rim/tire out of balance. It could be that your tire has a flat spot from peeling out or heavy braking. You should also get them force balanced. This is when they balance the tire to the rim with a load applied and it is the best balance you will attain. However, if your tire has a flat spot...you will need to replace it.

 

[Emay]

If you have 18's, it's common for them to not balance completely do to the lack of sidewall. I have 18's with Michelin pilot sport tires and had them road force balanced 4 times and I still have the exact issue you have. The road force machine had just been calibrated before my last visit to my buddy's shop. One of the more experienced mechanics there told me he sees that quite often. By the way, my steering wheel shimmy comes and goes.

He said 17's in the top of the post..

However I have the 18" wheels and experience no trouble with them what so ever. Matter of fact the car is surprisingly smooth.

This really sounds like warping of the rotors, how's your driving style? are you a heavy breaker? If you are, many of us are too, then an upgraded rotor may not be a bad idea. You could always insist on a stock OEM replacement, see if it clears up the problem, but then returns, then you would know for sure about a potential upgraded performance rotor being in your future.

 

[xbone]

My 06 with 17's and Pirellis has a very slight shimmy at 60-65. Seems to go with the territory on these cars, my 04 Mach had the same thing with a perfect balance and Michelin tires. Sometimes a tire will continually go out of balance because of a shifting belt. I dont know why they turned your rotors, that shouldnt make a wheel balance condition, the rotors should scuff the pads a bit while turning.

 

[denck]

Shimmy:

HI All,

I have had the rims and tires road force balanced twice, and they say they are fine.. The car is also brand new, had the shimmy was noticced the day after I bought it... It is the strangest thing, does it at different speeds from 55 to 75 or so.. Sometimes 60 is smooth, sometimes it is not, even on the same stretch of road..

The new stock tires did the same thing, just much less noticeable., the 18's seem to exagerate the problem. 20'w were the worst. THese are OE direct 18x9 chome bullets with a 36mm offset..

Any other thoughts out there?

I really appreciate any advice, this is driving me nuts, and I have rea others out there on this site with the same sounding issue, but the fixed it by removing the rotor clips. That has not helpe me unfortuntately..

Thanks!

David

 

[denck]

Shimmy

ALso, forgot to mention, the breaks have no shimmy or pulsation when applied.. SO I do not think it is the rotors..

CHeers,

David

 

[Spdfreak]

I have the same setup and have had no problems whatsoever.

 

[Marine One]

I have a 2007 GT with the standard 17" wheels & Pirellis. I noticed a very slight shimmy when the car was brand new. Over time it has seemed to have taken care of itself. I plan to rotate tires here in the near future (7,500 miles) so time will tell.

My two previous Mustangs (a 95 GT Conv and a 96 Cobra Conv) were terrible when it came to this problem. I often wondered if part of the problem was that these cars were convertibles and lacked some of the structural rigidity of a coupe.

Some lessons learned:
1. A warped rotor can cause a steering wheel shimmy while driving, not just braking. I had a slight shimmy & a pulsating brake pedal in the 95, so I pulled the rotors and had them turned at a machine shop. The guy told me that they were both slightly out of spec. When I put them back on the car the shimmy was gone.

2. Always, always, alway use a torque wrench to to tighten your lugs to the specified ft/lbs and no higher. I believe the spec for our cars is 100 ft/lbs. The spec for my 95 & 96 was only 85 ft/lbs. You'd be surprised how many tire shops wanted to just crank them down to 100 ft/lbs. Use a cross pattern and make sure you recheck the torque after about 100 miles. A good quality torque wrench is cheaper than a new set of rotors.

3. A road force balancer is the only way to go. It will allow the tech to match the tire to the rim. It will also disclose a high or low spot in either the rim or the tire. I bought a set of tires for my Magnum from TireRack and had them road force balanced when they were installed. The tech showed me where one of the tires was out of spec. I called TireRack from the shop and they made arrangements to send out a replacement tire. This problem wouldn't have been identified with a conventional balancer until the car was test driven, and probably then only if the tire was installed on the front axle. If it had been initially installed on the rear axle, by the time I rotated it to the front I probably would have been SOL in terms of getting a replacement.

4. If you're only experiencing this problem at certain times and at different speeds from one time to the next, think about your tire pressures. A ten degree ambient temperature difference equates to a one PSI change in tire pressure. Were the weather temps different and possibly contributing to the problem being at different speeds? Adjusting my 07 GT's tires to 32 PSI and checking them often seems to the best spot for keeping this problem to a minimum. Conversely, the 96 Cobra did much better with higher front tire pressures.

5. Consider other mitigating factors, such as locking lug nuts. Might be worth temporarily swapping out two regular lugs from the back wheels and substiuting them on the two front wheels so that all five lugs are the same, and seeing if it helps.

Just my $0.02, hope it helps.

 

[denck]

Thanks Marine One for the comments, I am going to try the locking lug nut swap from the rears to see if that makes a diff. Also keep a close eye on my pressures. I last set them to 32 lbs a few weeks back..

Do you think a rotor can be warped and not feel any pulsating in the pedel when braking?

Also, they have been road force balanced, but not force matched to the rim. If I jack the car so te tire is just off the ground and spin it, it does have a high spot that hits the ground and stops the tire early.. Maybe a few milimeters high. Wonder if that can have an effect with the temps?

Also, you are correct that it does it at diff speeds and times throught the day, early morning coldness seems to be worse..

Thanks again for your comments, I am hoping to hear from someone on this forum who fixed this with it not being the rotor clips as the solution.

I am taking it to a race performance allignment dhop tomorrow to see what they can find..

Cheers,

David

 

[discofan]

Guys,

I run a 2005 GT and recently switched to an 18" Foose wheel with 255/45/18 in front and 275/40/18 in back...

I have the same problem at 60MPH only...

No pulsating brake pedal and no bad effects under 60MPH or over 60MPH...

When I drive slower than 60MPH, no wheel shimmy and when I drive over 60MPH, I have no shimmy... ONLY AT 60MPH EXACTLY!!!

I trust you guys before I trust a mechanic to sell me something that I probably do not need so I'll stay at this forum to find an answer...

My car has about 6,000 total miles on it and is not lowered in the front...

I do have Roush lowering springs in back with an adjustable panhard brace but that should not play a part in this bizarre issue...

Had the wheels conventionally balanced twice but I still have this problem...

If a "Force Balance" is the answer, then I run out and get one...

Dave

 

[xbone]

Since the majority of owners are having this problem I checked the owners manual, and found the shimmy is normal, its listed under the "Driver Awareness Motoring Mechanism" or DAMM, which is supposed to remind us all its a Ford.

 

[denck]

Well, I tried the lug nut switch to the front and set the nuts at exactly 100 foot pounds each.. Went for a tet drive and it seemed almost gone for the first 5 minutes or so, then came back.. Seems it may be a little less than before, but maybe it is my mind.. Well, off to the race allignment shop out tomorrow to see what they think..

This is so strange.. I love the car, but not sure if this is worth the stress..

Anyone else with some thoughts? It realy does seem like I found a few others with this problem whils searching the forums... Maybe this is just a ford annoyance in the end, but a new car should run smooth..

Cheers,

David

 

[manystangs]

I have been told that SOMETIMES if you balance the wheels and put the weights on only the inside of the wheel and not on both sides it COULD cause a shimmy. I had asked about just putting the weights on the inside of the wheel and was told this. I would like to think that if you used the stick on weights and positioned them as close to the centerline as possible it would not shimmy. Just my $.02

 

[Marine One]

I have been told that SOMETIMES if you balance the wheels and put the weights on only the inside of the wheel and not on both sides it COULD cause a shimmy. I had asked about just putting the weights on the inside of the wheel and was told this. I would like to think that if you used the stick on weights and positioned them as close to the centerline as possible it would not shimmy. Just my $.02

I always thought that if you put the weights on just the back the wheel isn't really dynamic balanced but static balanced instead.

 

[Marine One]

Also, they have been road force balanced, but not force matched to the rim. If I jack the car so te tire is just off the ground and spin it, it does have a high spot that hits the ground and stops the tire early.. Maybe a few milimeters high. Wonder if that can have an effect with the temps?

I would have to think that a tire that is out of round enough for you to see it as you've described could be contributing to your problem.

Well, I tried the lug nut switch to the front and set the nuts at exactly 100 foot pounds each.. Went for a tet drive and it seemed almost gone for the first 5 minutes or so, then came back.. Seems it may be a little less than before, but maybe it is my mind.. Well, off to the race allignment shop out tomorrow to see what they think..
Cheers,

David

What seems strange is that this problem is intermittent. I once had a tire guy tell me that if there is excessive moisture inside the tire it could cause the tire to not stay balanced. Something to at least consider I guess...

 

[denck]

SHIMMY FIXED!!

Just got back from the race allignment shop.. THey fixed the shimmy! FIrst problem was that the OE DIrect bullet rims were not truely hub centric as they told me.. THey were actually riding on the studs.. The shop was the only ones to figure it out and do a spin balance fromthe studs instead.. They next balanced the tires after mounting them back on the car.. They took an ounce each to fianly balance on the car..

Now for the first time since I got it two months ago, I have a perfectly smooth running car! Yehaawww!

If you are in the bay area and have a shimmy problem that can't be figured out, call Custom Alignment in Mnt. VIew, CA.. Here is their website: www.customalignment.com/

Out of five shops and the dealer, they were the only ones who figured it out..

CHeers,

David

 

[xbone]

Don't understand your diagnoses, are you saying they weren't mounted flat on the hub? Or that they were out of true? An out of true rim can be balanced, it just takes more weight. If these are factory rims, exactly what did the tire shop do to correct it?