Hi all. Owner of a very clean 1990 Corvette. Problem i’m having is a very heavy vibration ONLY at 55 mph or higher. Drives super smooth under that. Put 4 new tires on it and had them perfectly balanced so that’s not the problem. Ideas of something simple I can check? Appreciate the help! -ChevyGirl

 

U joints?

 

how any miles on your car? can you feel the vibration in the front/does the steering wheel shimmy at that speed too? hands must be loose on the wheel during this test. or does the steering wheel feel fine, with the vibration feeling like it's in the rear? sort of like a little wheel hop felt in your seat. does the car want to drift left or right on a very flat road (one with little road crown), or does it track pretty straight?

did this vibration just come on recently, or always there?

if new tires did not solve the prob, there are some possibilities: one or more of the u-joints might be worn, maybe a slightly dented wheel, maybe loose wheel bearing, wheel balancer at your shop out of calibration, shop having probs with experienced staff.

I just had this problem a few weeks ago on our family sedan, and solved recently. had the summer tires installed and then found the car wanted to drift slightly, also had front and rear vibration between 50 - 60, with steering wheel shimmy too. took it back to the shop and they said the wheels were then re-balanced, shuffled around from front to rear and side to side, and had their best mechanic on it. no change. I was told the brake rotors were warped, and that one or more were grabbing and releasing the rotors when driving, causing the out of balance feel. after 15+ years at this place w/zero prob, I thought this was total crap.

so I took it to another shop. I asked them to check for poorly mounted tires and/or out of round tires, and had them re-mount and balance the wheels. problem solved. they said all the wheels were out of balance when checked, the wheel weights were only installed on the one side of the rim {they balance using weights on both sides} and they found a slightly dinged wheel on the front which they moved to the rear. prob solved.

 

50k miles. Vibration is heavily felt in the steering wheel and hands off the wheel you can see it shaking harshly. No drifting, goes pretty straight. Vibration has been happening for a year now (only drive it in the summer).

 

that really sounds like an imbalanced wheel, or a loose steering component. worn tie rod end, ball joint, power steering cylinder end, control arm, etc. I'd have the front end checked by a reputable shop the specializes in alignments, wheel balancing. does not have to be Corvette specific, and i'd do this pretty soon. could be dangerous, and will wear out your new tires. good luck.
bob p

 

Check the brakes after driving. If any wheel is noticeably hotter than the others, that’s a sign of a sticking brake caliper.

 

One thing is for sure, if you find a good tire shop, stick with it. I use just a locally owned place, they do real good work that I I know I can trust from experience in taking my cars to them. And they offer a very reasonable discount if you pay in cash.

The unfortunate reality, though, is that good tire shops are fewer and farther between these days. So many are just so half-assed.

Just to add as an afterthought, maybe look into having the tires indexed as well.