I have had this vibration since ive owned the car about 10 years now. I took the Vette out last week for the first time this season and noticed its getting worse. I already went through 3 sets of new tires mounted and balanced and 2 or 3 wheel alignments since ive owned the car and she still has the shakes.
Around 60MPH and up is when you can really feel it. The steering wheel shakes as well as the whole car. Also when I take off from a stop a hear some clanking noise coming from the rear of the car. I told a mechanic about this problem and he said it can be the driveshaft and half shafts that are off balance as well as having worn u-joints. He also said its a common problem on 85-87 Vettes. Can this be true?.....if not any suggestions on what else it may be. Thanks for your help.

 

anyone?

 

yeah, according to the helms, both those things can cause that. if you get a clunk while going into drive the u-joints can be bad.

the steering wheel shaking is something else though. i would think the driveline problem would cause a generalized vibration. the wheel shake suggests some kind of front end problem--bearings, tie rods, worn bushings. you might have a combination of both problems.

they've a troubleshooting section in the helms that should help diagnosis. if you don't have one check ebay. i picked mine up for forty bucks shipped.

 

On my '92, all the balancers didn't solve the problem until I found someone that used this:
http://www.gsp9700.com/pub/technical/4127T/4127t.cfm

The most important paragraph in this text:
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Wheel Balance
Have you ever heard a customer say he is still receiving wheel vibration complaints after he has balanced wheels? Many people do not realize that balancing is only a small portion of wheel vibration. If the wheel never came in contact with the road, then balancing would be sufficient. A square wheel can be balanced, but a square wheel will not give a smooth ride
________________________________________ _______________________



Tom Piper

 

Bent half shaft, out of phase or bad u-joints are my guess. Pull the rear wheels and see if you have a lot of movement at the joints.

 

I think you have two problems.
One in the rear causing the clanking and the other is wheel runout/stiffnes (not an unbalance condition) variations.

I can't see rear u-joints or half-shafts causing the steering wheel to shake.

Tom Piper

 

I just did this on my '92 over the weekend...

I was getting a heavy clunk while shifting into driving gears at a rest and a clunk followed by a metal grinding noise from my driver's side rear wheel, while accelerating, till around 30 mph. I also had a vibration at 60-70mph that was easily felt in the steering wheel and the whole car.Turned out to be a bad u-joint on the pumkin-side of the half-shaft. (The u joint actually ground-down a few needle bearings allowing for a fair amount of play) The job is fairly easy, just nuttin' and boltin', just take care when you drop down/put up the transverse spring, I'm sure it's possible to lose a limb if you're not careful.

I jacked up the car on the driver's side, tranny in N, and grabbed the half-shaft and twisted it back and forth to detect any slack. The wheel side turned immediately while the pumpkin side had about 1/8-1/4 of play before it rotated the pumkin yoke. I could also move the half-shaft in North, East, South, West directions about 1/16-1/8 of an inch.

Replaced both u-joints on the half-shaft, took the car out, and it felt perfect. No clunk, at anytime, and the vibration is completely gone from the wheel and the whole car. The car feels like it's doing 5mph at 65mph.

To clarify my definition, my steering wheel was VIBRATING, not shaking. The same type of vibration you could feel throughout the entire car, you could feel accentuated through the steering wheel even more. If you're wheel is shaking, I think you might have another problem.

 

You know... After messing around with this (My) car ('85, flat top 355, small cam, etc..) for nearly 4 years trying to find a persistent "driveline" vibration - most noticeable around 80-85 mph - I have been through it all: u-joints, balance the shafts (all of them, and mess around with "clocking" the main shaft - like the Helms manual sez...), wheel bearings, different wheels (after many trips to the balancer and several sets of tires), etc... I changed out the Exhaust system a few months ago - and the vibration is gone.

I Know that the front exhaust hanger - at the front of the converter - is "bad" - the rubber isolator is deteriorated, and it doesn't seem to be available anyplace that I've been able to find, so it's still on there.

Still - the Exhaust? A Different system - including putting a high flow cat back on it (didn't have one at all before) - has eliminated what I, and everyone else who rode in the car, was certain was a wheel or bearing problem - that exact kind of speed related vibration.

It's nice to have the car smooth at any speed - but I would never have suspected the Exhaust of being the culprit. It's Never too late to learn something new

 

Sounds like you already have some good feedback. When it comes to wheels and vibration, the rule of thumb is if you can feel it mainly in the steering wheel, it is the front end. If thru the seat, like when it makes your butt tingle, it is from the rear. I agree with the thot it is probably two separate problems, one being wheel balance.

 

WHen a rim is out of round or damaged, it can still be balanced to zero on a balance machine but will never be vibration free. I had 4 repaired camaro ss wheels off my brothers car at one point that always balanced, but were horrible at highway speeds. the vibes were in my butt And the wheel (he smashed his car at mosport breaking 2 and hitting the other 2 wheels pretty hard ).

When i replaced the wheels with brand new wheels. all gone.

 

I agree. Many times the minimum-wagers that man the balancing machines never bother to look for a bad wheel (bent, dented, etc.). They simply put the wheel on the unit, put the cover over the wheel, spin it up, and look at the screen.

Have your wheels put on a dynamic balancer and check BOTH sides of the wheels for trueness. Then, look at the U-joints.

Larry
code5coupe

 

I had the same problem replaced all the joints now no problems

 

If they are bad enough(like mine) it will shake the whole car

 

very good input, my has begun to suffer from the same thing, i will take it apart this weekend.

 

I want to thank tom piper for the tip about the GPS9700 balancer, after haveing my wheels balanced at 2 different shops with out success, i saw his thread and found a place 10 miles alway with the GPS9700 and it fixed my viberation, and was very reasonable, thanks again i can now enjoy driveing again..........

 

You're welcome.

I've been there too.
I had my wheels and tires balanced at about four different places with no luck -- and, they start telling you that you have other problems.
One spin on the GSP9700 and all the problems went away.
I think there are now other companies besides Hunter making similar vibration analysis machines -- just ask for a machine that has a roller that simulates the weight of the car when doing the balancing.

The hardest part is convincing someone to try it because with most "normal" automobiles you really don't need it as much. The Corvette stiff suspension and non-balloon tires actually requires this type of machine.

However, it is important to keep in mind that not all tires and wheels are a matching combination.
If you are buying tires, it is best to buy them at a place that has this machine.
Then, if a new tire will not "true" out when installed on your wheel, the tire dealer just puts that tire back and pulls another one off the shelf that will.
You can't expect them to exchange a tire that was bought somewhere else -- they will just attempt to do the best they can do with your existing tires. And, that may be less than desired.

To those with unresolved vibrations, try it once and you will never use any other balancer -- even for your luxobarge.
http://www.gsp9700.com/pub/technical/4127T/4127t.cfm

This seems to be the Corvette community's best kept secret.

Tom Piper

 

Well i am a newbie to covettes, but i had a similar issue, and it turned out to be the bushings in the A-Arms were worn badly (also got the clanking noise, which was the A-Arms shifting as the busings were almost doing nothing to keep it still) So i got a front suspension rebuild kit and replaced the bushings, tie rods, and ball joints and now it drives good as new !!!