I recently installed new tires and Y2K wheels and now can't seem to find anyone who can get the vibration out of them on the highway.

I was told to seek out a place that had the Hunter 9700 machine, which I found at the local Chevy dealer. After 4 hours of fiddling with the wheels/tires and $81.00 later, the car now shudders at 70 mph worse than it did when the kid with a bubble balancer installed the tires. When I complained the service writer stated they just "couldn't spend anymore time on it", and brushed me off.

What am I to do? I can't live with this literally "thundering" vibration while cruising down the boulevard.

I take it this Hunter equipment is not necessarily "foolproof" in that the mechanic must have some ability to operate it for it to be sucessful in eliminating balance problems. At least I know not to go back to that particular dealer (or probably ANY dealer again).

I'm certainly open to any reasonable suggestions.

Karl


[Modified by MagikDraggin, 9:57 AM 12/16/2002]

 

You may have a wheel that is not true or a tire that is out of round. Did the dealer check for those conditions?

"Not being able to spend more time on it" is a good sign to take your business elsewhere.

When I bought new tires, I had the local community college do my mounting and balancing. They had just taken delivery of the (then) new Hunter GSP9700 system and the instructors were looking for projects so the students could learn the equipment. I told them I would be doing some open track events and I wanted the tires balanced for high-speed use. They did a great job and the kids had a whole lot of fun working on the Vette (under my watchful eye!).

Check out this page on the Hunter website: http://www.hunter.com/pub/product/balancer/Balancer.htm
There is lots of information on what this system can do. There is a locator feature that should give you the location of a machine in your area.

 

Quote:
"You may have a wheel that is not true or a tire that is out of round. Did the dealer check for those conditions?"
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If you're talking about "runout", yet that was checked and no problem found. When I jack the car up and get the wheels spinning, there is a noticeable visible "high-spot" on the tires. Maybe I am just too gullible to have thought a dealer could have fixed the balance problem.

Does anyone feel having the tires "shaved" to remove the high spot I see, would do any good?

Karl

 

It is possible that it's not a problem with the wheel at all, but rather one of the tires. What brand are they and where did you get them? Were they new, had they been mounted before, etc, etc?

 

Quote:
"It is possible that it's not a problem with the wheel at all, but rather one of the tires. What brand are they and where did you get them? Were they new, had they been mounted before, etc, etc?"

All 4 new tires. Factory replacement brand and size, Goodyear HP Ultra plus P285 40ZR 17 from Tire Rack.com

Karl

 

The vibration started immediately after the tires went on? I suppose there's a rare chance that one of the tires is defective, but the balancer machine should have caught that.

At 54k miles it's worthwhile to check for worn suspension components while it's on the lift. Wheel bearings, tie rods, ball joints.

 

Couple of ideas. If you still have the old wheels and tires put them back on. Do two at a time (front or back) and see if the symptims change. Got a friend with a vette? Swap the tires out two at a time (front or back) and test it out. Did the vibration move to the other vette or disappear from yours? Does it shake in the steering wheel or just seat of the pants vibration? Swap the the tires from the front to the back? symptoms change?. Take them to another alignment shop. Mark where each weight was and its weight on the tire before taking the weights off. Have the tech do this. Got a digital camera? take before pictures. Have the new tech rebalance them. If the weghts change significantly in weight or location have him document it (if he will). problem solved? if yes then take the info back to shop one and show them where they messed up and get your money back.

Get a cheap dial indiator and measure the runout on the tires in the middle of the tread. If its bad (I don't know what is bad) call up the tire place and give them the info and see what they say. If you shave the tires they are only going to last as long as the most shallow spot that is left. Its a real shame if you have to shave 50% of the tread off to get them balanced

If you go the dial indiator route also check the rims themselves both lateral and radial runout. Lastly do the rims bolt to the hubs correctly? Is there any possible way they don't or the lug nuts are wrong for the rims?

I have watched guys put weights on rims on my vehicles that cover almost 1/4 of the circumference and tell me that is what it needs when the previous tire on the rim only had 1 or 2 small weights.

I don't know about those particular rims but you also might look into finding an 'old timer' that can spin balance them on the car and see what the results are.

One final thought. Maybe the guy that mounted the rims on the car torqued the snot out of the studs and warped the hub/rotor assembly or messed up the rim.

Good luck with the diagnosis. Let us know what the problem was when you find it.

 

Quote:
"...you also might look into finding an 'old timer' that can spin balance them on the car and see what the results are."
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It was the young son OF an oldtimer that originally balanced the tires with an antique bubble balancer. Then he also spin balanced them. It was really a respectable job and he admitted it is not "perfect".

Being the nit-picker that I am with this sort of thing, I took it to the Chevy dealer that had a Hunter 9700 machine......hell, everybody said this machine will remove ALL vibration. Not this time I guess.

Just got back from an "official" tire wheel dealer in town that also has one of these machines and he said the two rear tires were way out....one was 3oz off. The left front was close but he made it better.

The right front however has what he called "excessive force variation", which in ordinary people talk, means there is a super hard spot in the tire rubber itself which he cannot compensate for, over the entire rpm range.

I will do the wheel/tire swapping tomorrow weather permitting (I still have the original sawblades)....and no it did not wobble and vibrate with the sawblades on. The new wheel guy today also verified there is no run out on the wheels themselves.

It still vibrates some...depending on the speed. Very slight jiggle in steering wheel at 68mph, mostly an up and down vibration at speeds above that. I will contact customer service at the Tire Rack and see what they have to say about the matter.

Thanks all for your input so far. Is it just me that is having all this trouble, or is this fairly typical with Corvettes with these wide wheels (9.5")?

Karl


[Modified by MagikDraggin, 4:31 PM 12/16/2002]

 

The "excessive force variation" and the "hard spot" would be reason enough to get with Luke at the Tire Rack to see how to get a replacement tire. Shaving the tire may not be of any benefit if there is a problem with the construction of the tire. I would expect that this would be a warranty deal.

 

Wow, quite a bit of trouble you've gone through with those tires. :crazy:

Glad you've finally narrowed it down to a bad tire. I was one of the ones who recommended the hunter machine. I was under the impression that it was foolproof, but your experience shows it isn't.

I've been buying tires from tirerack for almost 10 years now, and they have been a pleasure to deal with and very accomodating. You should have no problems exchanging the faulty tire for a new one. They have done it in the past at no cost to me. I hope you have the same experience.

Good luck, hope you get it all figured out in the future. I really enjoy my Y2K rims.

J

 

Magik; Sounds like you are on the way to fixing the actual problem. It also appears that the guy running the first 9700 needs a LOT more training. My local dealer had a training session in house from Hunter when they bought the machine, but then again they pay bettter than others in town and don't have much turn over in mechanics. The places that keep their guys are the places where I prefer to spend my money. If you see a different set of tool boxes or a constant change in service writers, don't stick around too long, most likely they aren't trained too well or have a lot of product knowledge. //Dave

 

Thanks "C4cruiser", for the info as to whom I should talk to at Tire Rack....I was wondering how I was going to handle that one.

And Dave, it has definitely been a "learning experience". Still, thanks for all of your help as well.

I come back to this post if it's still reasonably active and let y'all know how this turns out.

Karl

 

Have seen tires that will not balance over the rpm range. Very very few but they occasionally pop up. Sounds like you finally found someone who did their best and narrowed the field. Long time ago before tire company(s) instituted quality control as part of the plan, NEW tires would be "trued" at point of sale. The machine was a slow turning tire lathe and you would shave off or otherwise trim the tire. Somehow, if excess or more dense material is concentrated on the sidewall or internally/tread area, just won't balance. On older style higher speed balancers (like the older John Bean) you could see the tire start to "jump", then smoothen out when the balancer reached top speed. Suspect they have slowed down balancer RPM for safety reasons plus better measurement equipment currently used doesn't require high speed balancing.

Lot of work to figure out what is going on. Let us know.

Good luck.

dlmeyers 90 coupe zf6 3 speed shocks


[Modified by dlmeyers, 8:56 PM 12/17/2002]

 

OK! Got my replacement tire today from the Tire Rack. Luke is an excellent person to work with...thanks for the tip guys.

Anyway, long story short, had it mounted and balanced and "voila" no more "shake, rattle and jiggle".

Couldn't have done it without you fellas. THANKS! And happy holidays to all.

I'm gonna go out for a drive. So what if it's dark out? My 'Vette's not afraid of no dark.

Karl

 

Sweet! :cheers:

Glad to hear you got it worked out.

J

 

Glad you got the problem fixed, but I think I'd go back to the dealer and demand your $81 back especially since you have proof that they neither balanced the tires correctly or found the cause of your problem. They may have spent alot of time on your car, but they didn't fix the problem. I hate being ripped off :mad :mad :mad

 

Magik; Glad to hear it all worked out. I was beginning to wonder if my good experience with the Hunter 9700 was just luck or what? I'm also jealous that you can still drive yours, when mine goes into the storage warehouse, I can't get it out until April. All cars in the same day and out the same day. Maybe we can meet up at Porkie's sometime. //Dave

 

Quote:
"Maybe we can meet up at Porkie's sometime." //Dave
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I am pretty much a "regular" at Porkies on Wednesday and Saturday evenings, (in season of course). Seems like the place kinda went downhill real fast by September though. A lot of the antique and classic owners objected to all the late model Corvettes, Mustangs and Cameros that showed up and now they go to another spot north of town. Would love to have ya down for a visit though.

Karl

 

Is that maybe the bar up by I80 on Merle Hay? Daytona or something like that. Anyway, I'll be sure to let you know when I'm heading your way so we can meet up. Maybe make it a Corvetteforum night. //Dave

 

That "Daytona" place is nothing more than a glorified burger joint....no one brings their cars there to "show".

One block north of I-80, just up from Daytona, on the East side of the street is a large motel. Saturday evening is where the hotrods, classics and antiques go now. I'm not allowed in with my 'vette (too new).

Just lemme know when you'll be in town....we'll work something out.

Karl