rough ride
 

I have been on here before asking for help on this issue. Originally on occasion you would be driving on the highway and for no apparent reason the car would begin to vibrate as though you actually had a flat tire. I replaced the tires, replaced the adjustable shocks with a standard shock which did not resolve the issue. Most recently through help on the forum I replaced the rack & pinion.
Although the ride does not react like driving on a flat tire, it stills vibrates badly on occasion. Just had it out today and it did it after driving fine for several miles. Don't know what to do next any advice would be greatly appreciated.

vibration
 

hi tom have you checked all of the u joints? they can cause vibration
also i know you got new rubber what brand did you buy and were they road force balanced ? (a means of detecting sidewall issues) rather than standard computer balancing. look it up on line.
i have a vibration , had my tires rebalanced with no luck. some one on the forum gave me the heads up
i found a shop that had a road force balancing machine. when the mechanic finished up he informed me that both my front tires were out of spec by 30 percent or more which is y they vibrate.
limited to the steering wheel only. he was able to improve them by 30 to 40 percent based on before and after. i'm running nittos which appear to be a decent tire for the dough.
im sure the are many reasons y cars vibrate and sometimes identifying the problem is a pain
https://cimg3.ibsrv.net/gimg/www.cor...302c261454.jpg

I have not checked u joints yet, do not have lift. I put Goodyear Eagles on the car, I believe a quality tire. I recently had another corvette owner on another corvette web site also asked if they were road force balanced. I am sure they were not. I had not heard of this but I am going to check it out and see if someone locally can do it.
thankyou very much for responding

Might check your wheel bearings also as that can be another source of vibration. Let us know what you find out.

Can you feel the vibration mostly in the steering wheel or is it general body shake?

espy1949, very sweet ride; love the color. Is it MN6 or auto?

It is auto. You do feel it in the steering wheel, but the whole vehicle shakes. I went for a ride again this week and it dld it after driving over 40 miles. Got off the interstate and got back on and it had stopped. That is what makes it so hard to analyze. Had someone say I should check motor mounts. Any info you may suggest would be appreciated. I have put it on a lift but all the u joints seem tight. Thanks for your response .

I was explaining my situation to someone at a car show yesterday and his response was you have death wobble. Upon checking the internet and YouTube that seems to be an issue with Jeeps and some ford and dodge trucks. Has anyone ever heard of this on a C4 corvette?

rough ride
 

Tom, Please let me know if you figure it out. I have a 1990 coupe that does the same thing although I wouldn't call it severe. I put on a set of new Kuhmo's and it helped quite a bit. I also installed new Z06 wheels, front wheel bearings, and had a wheel alignment done. The problem is just like yours it comes and goes with no rhyme or reason.
I also noticed you replaced your adjustable shocks with standard shocks. Was this a direct bolt on? I'm sick and tired of trying to troubleshoot my adjustable suspension and would appreciate any info you could give me.

John

John, I have not got it resolved yet. I recently, last month, had the wheels road force balanced, which had been recommended to me. I did not get half way home, probably 5 or 6 miles on interstate and it started it again. It seems to only do it at 60+mph. I do have after market wheels that were made in Twain and were on the car when I purchased it.. One person on another corvette blog said that could be the issue. I don't want to have the expense of new wheels and find the problem is still there, and it just seems like it would do it all the time if it were the rims. At this point not sure what I am going to do. I had the shocks done by my mechanic but I believe they were direct bolt on. The warning light for adjusting ride performance is always on, but I did see on the web how to bypass this but I just have not followed up to do it. The local chevy dealer at this point just does not drive it long enough to experience it.. I may try to convince them to drive it until it happens. I think they believe I am exaggerating. Keep me updated on your situation
Thanks
Tom

rough ride
 

Tom, Thanks for the update. I was going to mention wheels as one of my new Z06 wheels (aftermarket) was bent from shipping and Costco didn't catch it when they mounted them. If your wheels or tires were out of round or bent I would think they would have caught it when you had them road force balanced. I like you am at a loss for what else to check.
Thanks for the shock info I'm going to go ahead and order the standard shocks as I haven't tried that yet. I'm in Alaska and winter is setting in so my ability to road test will be severely limited until March. If I find the cure I'll let you know and you please do the same. Thanks

John