Vibration/shimmy above 65MPH

[FreedS4]

I've been trying to track down the culprit which is causing a slight vibration/shimmy in my steering wheel and seat at speeds above 65MPH. Every piece in my suspension (and brakes, for that matter) has been replaced within the last 6 months. I've got H&R race springs and Billy sports. I just tried re-balancing my tires this afternoon and rotated them when I put them back on and it didn't fix a thing. Any ideas as to what else could be causing the vibrations/shimmy?

edit: The vibrations start above 65MPH, stay constant until about 80MPH or so and then go away, for the most part.

[Philo]

Sounds hub related to me. Wheel bearings good? Using hub rings?

[sonnyqm3]

could be a bent rim. I just had this problem at the shop with a Nissan sentra and turned out to be bent rims... check em out..

[FreedS4]

Sounds hub related to me. Wheel bearings good? Using hub rings?

Haven't really checked into the wheel bearings, but I believe they're good. No sound coming from them and no rubbing/grinding when I spin the tires with the car off the ground.

could be a bent rim. I just had this problem at the shop with a Nissan sentra and turned out to be bent rims... check em out..

They're 1 year old D-Force wheels and I'm assuming they were straight when I got them. Haven't hit anything that would cause them to get bent. Can a tire shop tell me if they're straight and not bent?

[HSPD-561]

Mines been doing the same for a couple weeks now. It just started getting slightly worse at 80mph and above this weekend.

[SimplyDope]

Gonna have to go with bent wheel. Usually very hard to notice until it comes time to balance the wheels. Fairly common and usually happens on the inner lip. Could also be a hub like someone else mentioned.

[Philo]

Gonna have to go with bent wheel. Usually very hard to notice until it comes time to balance the wheels. Fairly common and usually happens on the inner lip. Could also be a hub like someone else mentioned.

He said he just balanced them. It's very easy to tell when the mechanic spins the wheel on the machine. I would hope he would have said something if he noticed it was bent. Also, since he said he rotated wheels, and it is still present, that is a good indicator that it is not a wheel problem. I highly doubt both front and rear wheels are bent the exact same to cause the exact same behavior.

[E30_fiend]

Gonna have to go with bent wheel. Usually very hard to notice until it comes time to balance the wheels. Fairly common and usually happens on the inner lip.

reading fails you

I just tried re-balancing my tires this afternoon and rotated them when I put them back on and it didn't fix a thing.

OP, what I would look for as well is bubbles or imperfections in the sidewalls on the inside of the tire. Depending on how your roads are, driving conditions, driving habits etc, the inner sidewall will get bubbles or imperfections. When they balance on a balancing machine, they will balance out fine but the actual unbalanced part will only give you problems off and on. I had the same problem you had. Went through and replaced control arms, complete tie rods, steering coupler, wheel bearings, hub rings, lug bolts and upper strut bearings(camber plate) and NOTHING worked.

Im telling you, check all of your tires for imperfections. The balancing machine will only pick up anything over .25oz of unbalanced wheel. If you think about it, if both front wheels have .20oz of unbalance then that equals almost .5oz of unbalance. That will create a hell of a wobble




Taylor

[FreedS4]

reading fails you





OP, what I would look for as well is bubbles or imperfections in the sidewalls on the inside of the tire. Depending on how your roads are, driving conditions, driving habits etc, the inner sidewall will get bubbles or imperfections. When they balance on a balancing machine, they will balance out fine but the actual unbalanced part will only give you problems off and on. I had the same problem you had. Went through and replaced control arms, complete tie rods, steering coupler, wheel bearings, hub rings, lug bolts and upper strut bearings(camber plate) and NOTHING worked.

Im telling you, check all of your tires for imperfections. The balancing machine will only pick up anything over .25oz of unbalanced wheel. If you think about it, if both front wheels have .20oz of unbalance then that equals almost .5oz of unbalance. That will create a hell of a wobble




Taylor

I'll look into that. What was your fix? New tires?

[SeriousBusiness]

My car did the same thing around 70mph on the expressway. Suspension and chassis parts all seemed to check out and I replaced any parts that needed it. New tires installed this afternoon seem to have done the trick. I've heard of tires being out of round, and I know tires will develop "flat" spots in many conditions. Car is smooth as butter now!

[FreedS4]

My car did the same thing around 70mph on the expressway. Suspension and chassis parts all seemed to check out and I replaced any parts that needed it. New tires installed this afternoon seem to have done the trick. I've heard of tires being out of round, and I know tires will develop "flat" spots in many conditions. Car is smooth as butter now!

I may have to invest in some new tires then. Thanks!

[Philo]

I may have to invest in some new tires then. Thanks!

You could also talk a friend into letting you borrow his wheels for a test. Throw a couple on the front (rear doesn't really matter) and go for a spin. It's better than shelling out for new tires on a whim. You don't want the reverse of what happened to Taylor: Replace tires and the shake is still there, turns out to be a different component.

[SeriousBusiness]

rear doesn't really matter

How do you figure? A messed up tire in the rear will attribute to vibration just as much as the front.

[JeffRR]

Ask the tire shop if they can measure "road force variation". Some of the balance machines can measure this.

Like others have mentioned, you can have a dynamically balanced tire, but that tire may no longer be round (flat spots, cords separating, etc). The output of a RFV measurement is a load, you really shouldn't be over 10 maybe 13KG.

[Philo]

How do you figure? A messed up tire in the rear will attribute to vibration just as much as the front.

Because the vibration is in the steering wheel, indicating the front. A problem in the rear wouldn't be felt through the the steering wheel.