89rag

Hey there, not sure how this works but here it is I drive a !989 conv for pleasure so it stays home mostly. lately I've noticed slight vibrations around 60mph
. I was told it was a wheel but I haven't hit anything and no-one else drives it. Also it seems to be getting loose like suspension parts are wearing out..I like doing my own work but I can use some of your expert direction. Thanks

1800Wing

How old are the tires ? Mine started to have vibration when they were worn out. Once I got them off the car I could see age cracks that I'd missed before.

later, tiny

cv67

could be lots of things usually something simple
get it up in the air start ckg one by one;start with tires, find the mfg date on the sidewall

When the suspension is tight meaning rebuilt these actually ride fairly decent not as bad as many would make them out to be

Sometimes the plastics work themselves loose makes the car seem worse than it is

89rag

thx for that i should have mentioned that the tires are new

89rag

thx. getting under it is a chore but can do..by plastics, do mean poly bushings?

gerardvg

Hi

What brand are the tires?

Could be out of round or they have no clue how to balance tires, get them balanced elsewhere.

The suspension bushings can be pretty bad and not give any vibration,
i keep thinking your tires may be out of round

DID IT VIBRATE BEFORE THE TIRES WERE CHANGED????

I just did my bushes on my 85 that has 170,000 miles on it, they were the original ones. While the trailing arms looked good the strut rod / spindle arms bushes were totally shot, the front bushes were a little worn. I did not have any vibration problems before doing the bushes, have you had your wheel alignment checked?

Jack the car up spin each wheel and note the tread, there should be no high spots. The rear will need the back of the car raised so both wheels are off the ground, Just start the car and put it in drive and see how they look.

NOTE, do not put the trans in park before applying the brakes to stop the wheels.

A normal road car with soft suspension will never really notice a tire slightly out of round, a corvette with stiffer sports car suspension will shake like crazy.

89rag

tires are UNIROYAL They had been on awhile before the vibration when I hit a bump it feels like something underneath is loose, could this be related

exitwound

Get the front wheels checked and rebalanced if the tyres are good. While the wheels are off, take a look around for any problems. The suspension is very tough and simple. If you had damaged something, it would show up more than just a vibration at 60.

Probably just lost a balance weight..

hcbph

Assuming you have the same size tires front-to-rear, try swapping the tires that way and see if the vibration moves or not. If it does then it's likely tire related.

You could have bad bushings or shocks but I would not think you'd get a continuous vibration from them. Tires or rims on the otherhand, definitely could. If on the other hand the vibration is short lived after hitting a bump, then it could be bushings, shocks or wheel hub related and you should closely examine them. On thing I found with the rear end, if you support the vehicle, remove the spring connection to one side and start checking out that side; if you do some shaking then bushing issues are easier to spot.

Good luck

89rag

Thank you all for your input. I will try them all this week when time allows.

vader86

Make sure the wheels are balanced, it could be tires too.

The bushings wear out, sometimes evaporate completely. Ball joint wear will cause vibration at speed as well.

DGXR

New tires eh... lug nuts tight?

A Peter C4

I just put new tires on mine with computer balance and had a vibration , had tires road force balanced vibration gone.

catso

I worked in a repair shop many years ago and that was the sure-fire method for detecting tire and wheel balance issues. Sadly, not alot of shops use it anymore.

dnovak1968

had same issue when I purchased my 96 vette. I checked everything and then finally took front tires off and cleaned the rim where it sits against the rotor. Cleaned the front of the rotor also where the rim sits. Tends to get a lot of buildup there. After that you MUST use a torque wrench and in a star pattern crank them to spec. Start a 25lbs and work up to what your car calls for. Mine needs 103lbs foot pounds. I really thought I had something major wrong, but that solved the problem. Now I can do over 100 with no shaking. Good luck. Torquing is absolutely vital to the wheels and will also keep your rotors from warping.

slow-vette

What he said. That is the first place to start. Make sure that the wheel face and the rotor face are clean. Rust and corrosion can cause things to get a little out of whack. Also clean and check the inside of the wheel. If they over greased the ball joints a glob of grease could have fallen off and attached to the wheel. This changes the balance weight and can cause a vibration. Make sure that the tire pressures are the same in all 4 corners. And finally if it still vibrates rotate the tires. Put the fronts on the back (assuming that you don't have staggered wheels) and see if the vibration moves. If it does then you know that there is an issue with the wheel / tire combo. If it doesn't then you have something else going on.

catso

Galvanic corrosion is a never ending issue with these cars and the addition of moisture, road salt and other contaminants means the problem never stops. I like to put a light coating of anti-sieze compound on the hubs and contact areas between the wheels, hubs, and rotors. It does not stop the corrosion, but helps slow it down.