: Front end shimmy



Ive's V
04-10-11, 04:56 PM
Hello all. I need your thoughts. My 27000 mile 04 has a front end shimmy that is driving me nuts. I replace the runflats with F1 GS-2 at 11000 miles. Since that day, I have a shimmy that comes and goes. I have rebalanced the tires myself 4 seperate times on different balancers. I have made enormous improvements and the car feels great. I take the car out again and I have this shimmy through the wheel. The car recently sat for around 2 months, but I figured, once the tires warmed up, the shimmy would be gone. Sometimes it is, other times it is there. This is driving me nuts. I have seen a lot of posts for tire issues with other Goodyear tires, having shimmy forever. I can't stand, that my Mini Cooper, with tires balanced on the same machine, is absolutely smooth from low speed, well over 130. I had the V, over 120 about 2 weeks ago, and smooth as can be. Yesterday, a constant shimmy coming in from 65 and staying. It tends to diminish higher up and totally in the steering wheel. Anyone have this experience and a ultimate solution or determination. I want a smooth V!

haroldabryan
04-10-11, 07:56 PM
I have also been fighting this since I bought my 05 a few years ago. The car has a warranty, so I brought it to a couple of different dealers. They would either rebalance the wheels, which didn't help, or say they couldnít reproduce it. After a few months of going back and forth with the dealers I started trying to resolve this myself.

I tried three different sets of tries from different manufactures, however the wobble would still come and go as you describe. In between buying different sets of tires, I bought a used set of wheels from a local owner and sent them off to be straightened. I used the same wheel company the local Ferrari dealer uses, so I figured it was a safe company. This still didnít fix the issue. I think my last option is to just buy a brand new set of wheels.

During the process of trying different sets of tires and wheels, I noticed if they werenít balanced with a Hunter road force balancer they would wobble worse and more frequently.

Iíve heard from other owners that they just get over it, while I heard of one that sold his car because of this.

I know this doesnít really help you, but at least you know you arenít alone. If anyone has been through this and resolved the issue I would also be interested to hear what it takes.

Ive's V
04-10-11, 09:30 PM
Thank you, I feel better. I am an adjunct automotive instructor and we have a Hunter road force balancer at school, but I'm afraid to use it for fear it has been beaten by the students and out of calibration. I do have access to a place that does have one and maybe I'll give it a shot and see. I'll post the results. You did make me feel better, thanks for posting.

Ive's V
04-11-11, 09:47 PM
Update. I roadforce balanced my left front tire today on a Hunter9700 balancer that we have at the school I'm an instructor at. I decided to do 1 tire, so I can judge if there is a change. I have to say, it is 80% better. I'm holding judgement to see if it remains this way, but I only have a little shimmy now at 67 mph. I had to rotate the tire, about 160 degrees to another point on the rim, then rebalance. On Friday, I'm going to do the other front tire, since that is my next class, and see if the remaining goes away. Then I'll do the rears. I am shocked as to the improvement, but leary, since this comes and goes. Look for the next update at the end of the week.

HeavyH20
04-12-11, 02:48 AM
Have you ever done an on-hub balance? Those are some huge rotors and I suspect that over time, they have a larger play in the balance game than just the tire balance. I too have an annoying shimmy from 62 to 67 MPH. I have three sets of rims and tires with winters, summers and track. One set is all brand new rims with brand new Eagle F1 Supercars. All have the same vibration at the same speed so I no longer think it is the wheels and tires. How are your front wheel bearings? Are those nice and tight with no play? The Caddie dealer by my work does on hub balancing so I was going to give that a whirl and see if the issue persists. I hope to get that done later this week or early next week and report back. I am curious to see how your efforts play out.

Ive's V
04-12-11, 06:21 PM
I checked the bearings yesterday and no play what so ever. Rotor balance can certainly be a factor, but this car is garage kept and the rotors really have no rust build up, so I'm won't rule it out, but don't think it is my issue...yet. On Friday, I'm going to roadforce balance the other front tire. I will post if that remaining shimmy is gone. After that I need several roadtests over several days to be completely convinced its gone. If that shimmy is gone, I will roadforce the rear tires as well. I am so curious as to how this car will feel after. After all, I don't have any shimmy big enough to shake the rear view mirror, but who knows, it could feel smoother after.

Ive's V
04-15-11, 10:15 PM
Update # 2. Today I roadforce balanced the other 3 tires. I taught my class today and before the class was over, I enlisted my slaves...I mean students...help me rotate the tires on the rims. I have to report, at least up to this point, that the car is 99% better. So much better, that I think regular wheel balancers are now irrelevant. I sold my repair shop several years ago and had the latest and greatest when it came to equipment and I knew about these balancers, but never really understood what they did. After researching and actually using the equipment for myself, I am completely amazed. I still had the ever so slightest something at exactly 67 mph, not 66, not 68, just at 67, where it was ever so slightly detected. This morning, I felt a vibration from the rear of the car. Kinds like the tires were flatspotted or the road was uneven. After the roadforcing, none at all. I have to drive it several more days to make sure, but as of now, it's awesome. I cruised home with the kids at 74 mph tonight, and it was enjoyable. I have been so bummed, that I wanted this car for so long, and finally got exactly what I wanted and didn't have the ride that I wanted. The vibration nagged at me. If it is truly gone, I am thrilled. Find a place that prides themselves in their work, and roadforce balance the tires. It makes sense, when you find out what it is compensating for, and that is what makes regular balancers, kind of obsolete. I think the amount of aluminum that makes up our front suspension, is what transfers that vibration through the car. If our cars were stamped steel like older cars, we may not have felt this, but I don't think the aluminum has the mass to absorb the unevenness. I just wanted to give you an update. Definitely, definitely give it a try if you are at your wits end.

Ive's V
04-16-11, 09:28 PM
Update #3, today, some shimmy above 67ish. Kinda was there more than I liked. Not as much as before the roadforcing. but more then my little victory post before. Today is was much cooler, so I'm curious if that is a factor. My pursuit continues

Ive's V
04-16-11, 10:37 PM
I had a new thought. What if the control arm bushings in our stock arms is what allows this vibration to build and transfer up the column. What about replacing the stock bushings to something else. That would account for the vibration to build during hard acceleration. I haven't found alternative bushings yet. Chime in with your thoughts.

Stepside
04-17-11, 10:30 PM
:hmm: What were the tire pressures in all 4 when balanced?
:hmm: What were they when you tested it?
:hmm: Were all little pebbles/stones removed from tire sipes in tread blocks before balancing?
:hmm: Did you pick-up any new pebbles/stones in tire sipes?

:sneaky: Explain: RoadForce Balance . .:bonkers: . static-dynamic-kinetic ??? divided weights ??
:hide: This is a 'pop' quiz . . :duck:

Glad to see you got your car back on the road, Ivan.
Mine is still on jack stands . . developing a 4th support for the Differential.

darkman
04-17-11, 10:46 PM
....

Ive's V
04-18-11, 09:51 AM
Tires were at 36 psi, no stones before or after. What roadforcing does, is it buts a roller simulating road force against the tire. It analyzes and picks up and difference in side wall pressure. If a portion of the sidewall is softer than the rest, that is like a flat spot. What the machine does is it finds this point on the tire and lines it up with best possible point on the rim to counter balance that spot out. You break the bead, realign the marks and rebalance. I did one tire first and was amazed on the results. I did the other 3 and on that night's roadtest, the car felt awesome. Granted that night was roughly 60+ degrees. The car sat in the garage for 2 days. I took it out accelerating strong onto the highway, and the steering wheel started to shimmy. From that point on, the shimmy was there. That is what I have found in the past. If I push it to the point there is a shimmy, it doesn't go away. Meanwhile other times, it feels great. The day that I pushed it, it was in the 40s, so I'm not sure if temperature is playing a role. I have yet to drive it again and see what it feels like. This is why I am starting to think of our front end design. So many have the same issues and have tried multiple tires and rims to no avail. That means, its a design issue with a cause. Either harmonics through our aluminum suspension components, a moving front subframe under load, or maybe control arm bushings that are not controlling the vibrations correctly. If the tire is balanced, it's balanced, it can't change, so the source of vibration is something in the car. I have owned my V since it had 10000 miles and now I have 27000. I have been dealing with this. There is an engineering error in our cars, and we need to focus there. Our cars have a lot of rotating mass, between the wheels and rotors. Something there is not controlling the vibrations properly.

darkman
04-19-11, 07:30 AM
See attached.

Ive's V
04-30-11, 01:42 PM
Update. Finally Today, I was able to get the vibration and spend some time swapping tires around. Everything looks like the LF tire is to blame. I've got to check a few things before comdemning it. All the tire were balanced several times, then roadforce balanced, then rechecked after. The spin true, no hops, no out of round issues, no damaged rims. My guess is that a belt is shift under load, even through it didn't show up during roadforcing. I'll post the success, when I fix this for good.

SRTTOCTSV
04-30-11, 07:27 PM
I have had that same damn vibration for the last 7 months and have had my tires road forced and road forced again (total 5 times i think) the last place i went to told me that three of my tires were high on the numbers but tracked good and didn't show any signs of being bad. the one tire was around a 9 i think. what are your numbers when you roadforce your tires? would 3 high and 1 low make that big of a difference?

Ive's V
04-30-11, 08:09 PM
Do this, simply swap the front tires to the rear and take it for a blast. See if the shimmy disappears, if so, swap one tire back to the front. If it comes back you know which tire it is. I have balanced my tires 5 times to no avail. I'm bringing the bad wheel over to my brother-in-laws to use is old bubble balancer. This tire is balanced on the machine, but is my cause. It will be curious to see if the wheel is balanced on the bubble balancer. If it is not, I'm going to add weight to balance it and see if it fixes it. If it does, awesome, if not, I'm ordering a new tire.

Ive's V
05-01-11, 09:42 PM
Interesting update. I took the problem child wheel and placed it on a static bubble balancer that was older than I was, tonight. Today, 65 mph, I could watch the steering wheel shake. The bubble balancer showed it out of balance by a little. 3/4 of an ounce brought the bubble to center. On my drive home, no shake! I'm not totally convince yet. Tomorrow, I'm going to blast it onto Rt 78 and see how it feels as I pass through 75 mph. If it feels different and naturally to the better, I'm rechecking the rest of the wheels. I was shocked to see the wheel not centered. Stay tuned....

Stepside
05-02-11, 08:57 PM
:holycrap: Wow, maybe the people that make the 'roadforce balancer' should be notified.
I would like to hear there explanation. :pop2:

I can see the Headlines now,
:quagmire:"Bubble-Balancer balances out the 'RoadForce' machine."

-- How embarrassing is that?? :coffee:

Ive's V
05-02-11, 10:01 PM
I would like to report it fixed! I didn't strip the weights off from the road-forcing, I just added the extra wait and took it for a ride. Gone. My steering wheel doesn't shake for the first time since I bought the car. I'm curious to how the other tires measure up. Absolutely unreal! I would have not believed it if I didn't see it for myself. If anyone has this irritating shimmy that no one can fix. Seek out someone with a good old bubble balancer and just put your wheel on it and see how it measures up. If the bubble is not in the center, add weight and level the bubble. You have nothing to lose. I still can't believe it but so far up to 90, nothing.