Remember that wierd vibration problem I had with my 87 back this winter? Well, I rebuilt the rear suspension (had a rear bearing going out which needed changing) - and put in new u-joints (it was time). This decreased the vibes, but didn't eliminate them. . :smash: My tires were about 50-60% worn at the time. I had a 4 wheel alignment, and had all 4 tires dynamically balanced. Still had that vibration, which was very pronounced about 70 mph. :crazy: It slowly got worse as the tires seemed to wear faster the last few months. It was that time that I had myself convinced that the tires were definately the source of the vibration. :eek:

Well, a few weeks ago I got new tires. The vibration is TOTALLY GONE! Infact the car is so smooth and quiet now I find myself looking at the tach to see that it's still running as I'm rolling up to a red light in city traffic. :cheers: :cool:

Just thought I'd mention it incase anyone else is tracking down a vibration problem. ~Juliet


[Modified by Juliet, 3:44 PM 7/9/2003]

 

As a matter of fact, I am...

...And I must admit that my prime suspect was my dry-rotted seventeen-year-old Goodyear GS-C's, but it's nice to know others have the same problem...

...Or maybe it's the original 102K mile u-joints... :crazy:

 

:cheers:

 

Well, mine were the original 120k U-joints and bearings too. ;) So it sounds like you could be in the same boat as I was. :)

 

What brand of tires did you get?

 

Kumho Ecsta. I was a bit nervous about them since their rating on wet pavement supposedly ain't that hot, but they're really no different from the Fulda's I had on the car before. It's my daily driver, battling the idiot driver's in Wash DC traffic, and we had a TON of rain this year. :eek: I can still stop faster than the taxi cabs can cut me off, and I haven't been sliding around either. :yesnod:

 

I am just now about to order 4 255R16 Ecsta 712's from TireRack at $89 each...

Did you have a better price??? If so, from whom???

(Whom; that's class!)... :D

Edit: Correction -

Kumho
ECSTA Supra 712
Blackwall
Size:255/50-16
$87 ea

If I don't get a better price [from other online tire hawkers] by morning, this order is going in...
:thumbs:


[Modified by Rich B., 10:02 PM 7/9/2003]

 

I'm no mechanic, but sometimes new tires cover up suspension problems. Dont be suprised if the same problem returns.

 

I have a 70mph vibration also. Mine is getting worse and vibrates worse as my tires wear. I know that I have a slight wobble on the right front wheel from the previous owners crashing a curb or something. There was a knot on the right front when I bought it and when I had the tires replaced the technician told me the wheel was out just a bit.

The interesting part is that when I installed a new set of tires at about 30K miles the vibration was (almost) completely gone. I'm now at about 83K and will need another set shortly. I plan on getting the wheel straightened at that time to see what difference it makes. It's only slightly out but I'm guessing it's just enough to cause the tire to wear and to accentuate it.
dr

 

I paid a bit more than $450 for the luxury of calling Wednesday, and driving Friday down to the local performance tire shop in Annapolis where they mounted, balanced and installed the buggers. :cool:

 

This may seem odd, but did they line up the yellow paint daub with the valve stem??? (Heavy spot on tire + light spot on wheel = better balance).

I had to call TireRack to find out. The Corvette manual tells you to, but my last set of tires had two paint daubs (red & yellow) and no instructions.

 

A couple of years ago I had the same problem. After getting new tires, my vehicle would vibrate at 70 mph and above. I had the tires rebalanced about four times and it was still there. But, before I got the new tires there were no problems.

I have owned several sport cars, including a '64 Corvette coupe that is still have, and still couldn't understand what was wrong.

Eventuallly, the tires wore out and I ordered a set of AFS wheels with the tires already mounted -- no more problems. AFS uses the Hunter "Vibration control system."

Take the time to read the details about this system at this site. This is not a bunch of advertising BS -- it is true. http://www.hunter.com/pub/product/balancer/index2.htm


The C4 Corvette has tires with sidewalls that are not ballooned like most vehicles, these sidewalls are short and straight -- they do not give and absorb shock or vibration. Plus, the C4 has a very stiff suspension. You will feel "run-out" and balance problems that you never dreamed were possible with "normal" vehicles.

The best way to solve this is to find some place that uses the Hunter GSP9700 Vibration Control system. This system actually puts a "load test" on the tire while it is being balanced to find run-out and sidewall stiffness variations around the tire. Then the tire is indexed on the rim to eliminate them.

As I have stated before, with my '92 Corvette, I can run over a dime on the road and tell you the date on it. But, with my Lincoln TownCar, it could have square tires on the rims, and I wouldn't know the difference. The vehicles have different intended purposes and will react differently because of the way they are designed.

I would never consider having my tires on my C4 balanced any other way again.

Tom Piper


[Modified by Tom Piper, 7:16 AM 7/10/2003]

 

Rich,
Give these folks a call. I got a set of inexpensive tires from these guys and couldn't be happier with them! P255/50/ZR16's. They look all the world like Bridgestone Portenzas...$77.00 ea / $365.00 for the set including shipping. I had them mounted and balanced at Firestone. The tire tech was very impressed with how little weight it took to true them out. He said they balanced out like a set of their Firehawks...I'm EXTREMELY pleased with the deal and the tires!

East Coast Tires
502 Industrial Park Ave
Asheboro NC 27204

eastcoasttires@yahoo.com

 

Rich,
I think the GS-Cs have only been in existance for about 12 or 13 years. Just an FYI. Either way, still a long time.

 

Hey Juliet :seeya haven't seen you post in a while. Glad to hear that you got it fixed.

 

Well, I've been wrong before... :yesnod: I'm on my 6th year with this Vette...

(And I had to use a calculator to figure out how old my '86 was!) :lol:

The tires have been good for me, but the dry-rot cracks scare me...

I'll check that East Coast Tires place out - what brand were those $77 skins???

 

Rich,
Did you switch to 17" wheels on your Pace Car too? Do you still have the original 16" wheels and 255/50 VR-16 gatorback tires?

 

Hiya Rich,
The brand name on the tires is Aurora. I was not impressed with the Dunlops that were on the car. And I just couldn't see putting pricey meat back on her for the way I drive. I'll never see a mileage rating come to fruition! Others see tire smoke and think "Cool"; I see undriven miles going up in smoke and dollars drifting away on the breeze. I see that a lot BTW. But I can't afford $530 for a set of plug wires or $1300+ for brakes...so. So a little research later I was ready to buy the Kumhos that's when I found these. I called and talked with Dave their salesman. He seemed very knowledgable and didn't try to over sell the tires but made me a great deal. I liked that. I'm old school and believe you get what you pay for so I didn't expect much. Every rule has an exception...for me...this was it. I started feeling good about the deal when the Firestone tech praised them after balancing and asked where I got them. After I put them on and drove a few days I was beside myself. The traction is at least equal to the dunlops but the ride and the quiet are far and away better. Very good wet traction as well.

I got lucky...just trying to share the love.

Good luck...pass it on

:cool:

 

MtlSphere -

Thanks for the info! :thumbs:

Ray -

I have the OEM 16" wheels only; they hold my car up. No Gatorbacks. :sad:

Juliet -

Thanks for the help! :yesnod: Glad to hear you're vibration free! :D