1986 Corvette, terrible Vibration at 65 - 75 MPH


#1

I have 1986 Gold Corvette, which now has Antique Virginia Plates. I had a terrible Vibration at 65 - 75 MPH that would shake the car so bad I could not drive it more than 20 minutes and I could not tell if it was in the front or the back.

I had the following installed: Front and Rear Wheel Bearing/Hub Assembly (Timken), Front and Rear Brake Rotors, Front and Rear Rebuilt Calipers, Front and Rear Hawk/ Wellman HPS Brake Pads and four Stainless Steel Brake Hoses.

Now the vibration is about half-gone, but still shakes the GoldVette at 65 - 75 MPH, and I still cannot tell if it is in the front or the back.

A few years ago, I replaced the Rack-in-pinion and Tie Rod Ends.

What do you recommend I replace next to eliminate the vibration so that I can drive it about 100 miles to Washington?

John G.
Glen Allen, VA


#2

John,

First, I would recommend pulling your personal info from the above post. It’s generally bad practice. You never know what strange person will decide to call at all hours and bother you. I can only guarantee it won’t be me. :slight_smile:

Have you had the tires balanced and the rims checked for true-ness?


#3

I agree. Sounds like a tire problem. Pretty much all that is left after all that work. Especially if the upper and lower A-arm bushings are tight as well as the ball-joints.

Had an alignment checked recently? The tires may not be wearing evenly if there’s an alignment problem as well, causing vibration.


#4

I had a similar problem with an 86 Camaro Z28 IROC after a tire rotation. The IROC came with 245/50R16 tires, I believe Corvettes of that vintage had 255/50R16s.

The Camaro’s tires had to be dismounted and remounted since the front and rear wheels were different sizes. After the tires were rotated, the first time the car hit 65mph it felt like it was going to shake itself to pieces. The mechanic did not balance the tires after the rotation. Once the tires were balanced, most of the vibration went away. The OEM Eagle VRs were very sensitive to balance and alignment adjustments.

Good luck,

Ed B.


#5

Very few of the items you have replaced have anything to do with vibration…Wheel balance / defective tire is ALWAYS the first culprit…Then, on a 'Vette, a driveshaft/halfshaft problem…A Wheel. Frame and Axle shop will sort it out quickly…


#6

I’d take a look at the U-joints in the driveshaft.


#7

GOLDVETTE - UPDATE

I took your suggestions and had an Alignment and the all Four Wheels Spin Balanced. L/F Off .5, R/F Off .5, L/R Off .75 R/R Off 1.5 Oz > Now Less Vibration, but still not great.

Then I purchased Two Duralast Gold, Forged Synthetic Lithium Grease- Driveshaft U-Joints and Four Halfshaft U-Joints and had them installed by my Mechanic. He said the front Driveshaft U-joint was bad, but the others were okay, but since they were 25 years old, it was a good idea to replace them.

Now, the vibration is the same as after the wheels were balanced.

It starts at about 25 MPH, when there is a little vibration in the Steering Wheel and in the Driver’s Seat. At 45 MPH there is more vibration and at 65+ the whole car shakes constantly. The Vibration is constant even in neutral at any speed.

So, now I have replaced:

Front and Rear Wheel Bearing/Hub Assembly (Timken), Front and Rear Brake Rotors, Front and Rear Rebuilt Calipers, Front and Rear Hawk/ Wellman HPS Brake Pads and four Stainless Steel Brake Hoses; as well as Two Driveshaft U-Joints and Four Halfshaft U-Joints.

Do you have any other thoughts on how to eliminate this vibration so that I can drive my GoldVette on a 100-mile trip?

John G.
Glen Allen, VA


#8

Have them put the vehicle on the lift and then “drive” the car at various speeds to see if either of hte rear tires or the driveshafts are vibrating. At least if nothing vibrates, then you know to look to the front.


#9

Tires and wheels. You could have a bent wheel or bad tire or both, If you could get a test set of wheels and tires to try, that would confirm it.


#10

You might have an internal tire problem. Try having the wheels subjected to a “road force balancing”. Those machines will detect internal problems that regular spin balancers will not.

Oh, and if you’re running Continentals you may never get them smooth. I’ve had vibration problems with Continental tires that could onnly be resolved by switch to another brand.


#11

Could be a tire with a broken belt. Are any of the tires showing abnormal wear patterns?


#12

Can you borrow a couple wheels/tires & put them on this Vette? Swap them out 1 or 2 at a time until you narrow down the bad wheel/tire.


#13

Had new tires put on and they vibrated at 65mph. Took it to NTB and they balanced them, no better. Noticed they did not put weights on the inside of the rims. There is no way to mount weights on the outside edge. Argued with them and they test drove it and told me it was fine and they would wear in. Went to Big 10 tires and they balanced them properly. No problems for 10,000 miles.
Had another set that the belts separated internally. You could see it on the tire machine when the lifted the guard. The tread moved back and forth.


#14

“they test drove it and told me it was fine and they would wear in.”

I always get upset when I hear things like this happening. And they’ve happened to me at the NTB in Manchester NH some years ago. They tried to tell me I had bent rims. I had them put the wheels on the machine and proved to them that the rims were fine. After much “discussion”, they finally did the job right. I never went back there. And i never will.


#15

And they’ve happened to me at the NTB in Manchester NH some years ago.

I went to NTB (Nashua) ONCE…They tried to tell me I needed new ball joints…I knew they were fine…So I asked them to show me…they could only say they LOOK worn…I was there for an alignment…Had them take my truck off the lift and left…200k miles later when I sold my 90 Pathfinder…the ball joints were still fine.

NTB use to be owned by Sears…Not sure if they still are. The mechanics at NTB work on commission. Each month the mechanics need to get a quota of $800 in parts. Anything over that quota and they start getting something like 20% for each part they sell. This is a great model for the workers…but lousy for the consumers.


#16

Aha. That explains their answer to me. But leaves me surprised they didn’t tell the OP he needed four new rims.

Telling people that things like vibrations will “wear in” upsets me. That’s a line of pure unadultrated balogna used by people who are either too lazy to go back over their work or people that don’t want their shop time used to correct problems unless revenue can be generated.