rhythmic vibration-
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
I feel my vibration in the steering wheel, so I thought it was in the front, obviously....but I jacked the REAR of the car and accelerated to 70+ mph and the REAR was VERY obviously vibrating.
Melting Slicks
Joined: Oct 2003
Posts: 2,655
Likes: 5
From: Brea CA
Well....
I don't think a No-Load test is the way to go... most cars, just jacked up no load on the suspention, or tires, will vibrate... The pulsing that is felt at 65-75 on the freeway is really annoying... You would be best to swap wheels and tires with a friend... it is free... if his car does not do it.. and yours does.. you are wasting your time on balance. My 98 C5 has repro chrome thin spokes, and non-run flat Nitto's 555 and it is smooth as silk on the freeway, 102,000 miles. I just bought a C6... so I will be selling the C5 soon... like to keep both... but hard to justify 3 Corvettes. 
Thread Starter
Pro
Joined: Oct 2006
Posts: 654
Likes: 1
From: Prescott Valley Arizona
How do you keep from screwing up the sensors by doing that? Wouldn't the computer say "Wait a minute, the front's not turning" and also the angle on the rear wheels would change since there was no up force on the tire? It may be possible to do that test with the front as the car doesn't have to be running but I would hesitate to do it with the rears- IMHO
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
Huh? Its no different than doing a dyno run. Your fronts stay fixed and your rears spin. Your ABS gets pissed off, you need to have traction control turned off, and you get a service traction control error that you have to clear...otherwise its fine.
I was thinking of removing the rear tires, putting the fronts on the rear and seeing if those vibrate too, that would tell me a little more about what's going on.
I was thinking of removing the rear tires, putting the fronts on the rear and seeing if those vibrate too, that would tell me a little more about what's going on.
Melting Slicks
Joined: Oct 2003
Posts: 2,655
Likes: 5
From: Brea CA
Well.... FYI
My C5 has no vibration... I jacked it up, and ran it to 70-75... it had the wheels vibrating, as there is no weight on the tires, and they change shape... unlike on a dyno... where the tires still have the weight of the car on them.... hummmmmmmm
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Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
Guess that's not a good test for the rims/tires then. I'm not looking forward to road force balancing....I already visually checked the tires and rims for blemeshes and they seem fine. I'll bring them back to the shop that mounted and balanced them and have them rechecked incase something is funky, since that's the free option...then I'll have to look into road force balancing to figure out where the problem is. I love the look of my 5 spokes over the wagons...I just wish they didn't vibrate so much!
Melting Slicks
Joined: Oct 2003
Posts: 2,655
Likes: 5
From: Brea CA
Bill...
My guess, unless they did someting really wrong when they balanced the tires, a weight fell off, the used too big of weights, and they hit the brake caliper, and knocked them off.. happens... if the wheels check out...you are looking at drivetrain... I know a lot of people bump a curb... that is all it takes to mess up a wheel bearing..
Thread Starter
Pro
Joined: Oct 2006
Posts: 654
Likes: 1
From: Prescott Valley Arizona
My guess, unless they did someting really wrong when they balanced the tires, a weight fell off, the used too big of weights, and they hit the brake caliper, and knocked them off.. happens... if the wheels check out...you are looking at drivetrain... I know a lot of people bump a curb... that is all it takes to mess up a wheel bearing..
Again some have said, these cars are tuned for specific tire weight and type and anything other may cause problems maybe stands true. Will keep posted if circumstances change.
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
My guess, unless they did someting really wrong when they balanced the tires, a weight fell off, the used too big of weights, and they hit the brake caliper, and knocked them off.. happens... if the wheels check out...you are looking at drivetrain... I know a lot of people bump a curb... that is all it takes to mess up a wheel bearing..
The variables in my situation are the 4 rims, and front tires. Everything was balanced, one tire actually came out to 0.00 on the machine (I'm a bit suspicious about that one). The new tires "could" be out of round, rim is bent, or they need to be reblanced...
Thread Starter
Pro
Joined: Oct 2006
Posts: 654
Likes: 1
From: Prescott Valley Arizona
50 dollar ded. but thats cheap- considering the car was 7 years old when I bought the warranty and essentially cost me 430 a year to insure against mechanical breakdowns-In this case one hopes for bad bearings-travel easy
Thread Starter
Pro
Joined: Oct 2006
Posts: 654
Likes: 1
From: Prescott Valley Arizona
I didn't give the whole history on my deal. I bought 4 used OEM thin spoke rims off a forum member. Swapped the rear tires and sensors from the wagons to the new thin spokes...then bought new front tires and had those mounted and balanced on the thin spokes. There was ZERO vibration before with the wagons.
The variables in my situation are the 4 rims, and front tires. Everything was balanced, one tire actually came out to 0.00 on the machine (I'm a bit suspicious about that one). The new tires "could" be out of round, rim is bent, or they need to be reblanced...
The variables in my situation are the 4 rims, and front tires. Everything was balanced, one tire actually came out to 0.00 on the machine (I'm a bit suspicious about that one). The new tires "could" be out of round, rim is bent, or they need to be reblanced...
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
I've got a sneaking suspicion that our problem may be in switching from stock to aftermarket wheels and going to the run flats. The weight difference (non run flats-lighter), heavier wheels, and with the different sizes 17 &18's may have created an imbalance somehow and began to generate a rhythmic vibration. The cars were designed for specific tire and combined weight.
Melting Slicks
Joined: Dec 2003
Posts: 3,315
Likes: 17
From: Near Jacksonville Fl.
rhythmic vibration
Frankly I'm beginning to think it has much more to do with the tire it self, more specifically the tread pattern.
I went from runflats on mag wheels (stock coupe sizes) to F1GSD-3's on repro Y2K Z06 sizes.
Frankly the weight factor was a wash due to the size increase and dumping the runflats.
My wheels have been checked and re-checked and road force balanced 5 times at the same Goodyear dealer by 3 different techs.
All with varying results, so it does matter who is running the balancer!
The car has only 53,000 on it and I have had it since it was brand new in 98 and had Never bumped a curb or damaged a tire or wheel in potholes.
Just wondering if there is a Goodyear Rep. we could contact to ride in 1 of our cars.
I went from runflats on mag wheels (stock coupe sizes) to F1GSD-3's on repro Y2K Z06 sizes.
Frankly the weight factor was a wash due to the size increase and dumping the runflats.
My wheels have been checked and re-checked and road force balanced 5 times at the same Goodyear dealer by 3 different techs.
All with varying results, so it does matter who is running the balancer!
The car has only 53,000 on it and I have had it since it was brand new in 98 and had Never bumped a curb or damaged a tire or wheel in potholes.
Just wondering if there is a Goodyear Rep. we could contact to ride in 1 of our cars.