What would cause a shake

[my88]

When im driving around 50- 80 mph i get a pretty rough shake to the front end. I have just replaced the hub assy on both sides , rack and pinoin, had an alignment, new wheels , new tires, new rotors and pads. Replace tie rod ends as well as ball joints. Even at 45 mph the steering wheel itself has sharp short distance shakes ....

[gmjunkie]

When im driving around 50- 80 mph i get a pretty rough shake to the front end. I have just replaced the hub assy on both sides , rack and pinoin, had an alignment, new wheels , new tires, new rotors and pads. Replace tie rod ends as well as ball joints. Even at 45 mph the steering wheel itself has sharp short distance shakes ....

Check your Lug Nuts,if thats not it check out the front tires for bad belts,and wheel weights thrown off!!

[John Robinson]

Depending on what tires you bought they could be directional and if one of them is mounted backwards that might be your problem.

Also even though you put on new brakes and rotors you may have a caliper that is dragging and it has warped one of the new rotors.

Also what Junk says is true just because the tires and wheels are new that does not mean they are good.

It also reminds me of the old days when we would pack front wheel bearings if the nut was a little loose we would get the car back with the complaint that is had a shimmy in the front.

[jmccloud]

Most likely a bad balance job; or perhaps one of the weights came off already.
Other potential causes are a bad tire (loose belt, etc.) even though new, bent wheel, worn control arm bushings or lousy shocks. If a shock is really shot, balancing becomes extremely difficult.
I'd ask for a check of the balance (actually spin them up) then look to the control arm bushings (visual) then replace the shocks if they're not new.
Good luck and welcome to a great site.

[my88]

do have directional tires mounted , they are on the correct way, new lugs nice and tug, brand new $1400 michelin tires just mounted last week balanced to zero in front of me at the shop. Had this shake before all the work and still after all of it. That's why i replaced the hub assys and the rack and pinoin also new shocks, and just checked the weights again all are in place still.

[TedC]

My88, When your tires were balanced, did they use a Hunter Force Balancer? This balancer is awesome, and can help isolate issues with either the rims and/or tires. I would try swapping front and rear tires and see if anything changes. Due to the different speeds this occurs at, I would also check out the shocks.

[JAKE]

My88, When your tires were balanced, did they use a Hunter Force Balancer? This balancer is awesome, and can help isolate issues with either the rims and/or tires. I would try swapping front and rear tires and see if anything changes. Due to the different speeds this occurs at, I would also check out the shocks.

I second the motion on load force balancing. I had it done to my new wheels and tires a month or so ago. Smooth as silk. Discount Tire charged me $20 a wheel/tire, which is $5 more than standard balancing.

Jake

[JAKE]

Are your wheels stock? If so, are the lug nuts stock too? Torqued to spec?

There's been a lot of talk lately about hub centric Vs stud centric mounting.

Jake

[Brewster]

Check u joints,I know it seams weard but i had it happen in a GTO.

[Paul Higg]

Rag joint?

[Brewster]

Front driveline universal joint . at that speed the vibration can shake the whole car depending on which u joint it is .On a Corvette even a axel ujoint will also cause that ,it acts like wheel shake.
On my 86 I get a slight puls shake when braking,haven't checked but belive it's roter not being true.
Good luck Brewster

[dmd]

Let's think about this logically. You only get the shake at speeds over 50. So that means that it is something that is rotating in proportion to the speed of the car and imbalanced that is causing the shake. Only a couple of things have those properties.

Since a steering rack doesn't rotate, nor do the tie rod ends, nor the brake pads, they wouldn't cause it. Also, since Corvettes are not front-wheel-drive, there is no driveline universal joint on the front axle. Rag joints are only used on the steering column, and they don't rotate either. So we can rule those out too.

The force exerted by an imbalanced rotating assembly is multiplied by its distance from the axis of rotation. So the further from the center, the larger the imbalance will be. So we can rule out a hub imbalance, because it isn't far enough away from the rotational axis to cause a vibration you'd actually feel.

Rotors generally only cause a shake like this when you apply the brakes, not when you're just cruising down the highway. Unless they were made in China.

Shocks damp the forces of imbalance, but don't contribute to them.

This leaves wheels and tires. Definitely find a shop with a road-force balancer, Hunter model GSP9700.

Also, check the castle nuts on all ball joints to make sure that they are tight and the lock pins are in place.

Dave D

[Cruzen]

You said you had this problem before all the work and it remains now after all the work. That seems to be the key!!! Then it may be something that was not changed out like a wheel gone bad. Can you steal a set of wheels and tires off another Chevy. Yes it will look gross for the test but that will tell you if it's a balance problem.

I would also check out the bushings as a worn bushing will allow the suspension to move around at higher speeds causing such a vibration.

Have you had a four wheel alignment?? If nothing else, overinflate the tires to 5 PSI over MAX and test it out. If the alignment is off, I find that the higher the pressure the less the car will shake. Lower pressures will amplify shake caused by bad alignment.

I had a wheel that balanced out OK but the rim did not run true. When I took the tire off and checked the rim by rotating it at speed on a balancer, it had a slight but noticable side to side movement. The guy at Discount tire did not think it would cause a problem but it did. I replaced the rim and the problem went away. This problem occurred with one of those "reproduction" rims I bought through eBay.

If the wheel does not mount flat against the hub it will not run true and will vibrate. One of my wheels, on a race car, had a piece of metal that was caught between the rim and hub and got compressed. I did not notice it until the car shook at top end. We took that wheel off several times before we noticed it against the wheel hub. Also I would check to verify that the lugs are bottoming out against the rims. Some lugs are not tapped deep enough so they torque down against the lug bolt and not the rim.

Good luck in finding and fixing you problem.

Enjoy the ride,
Denny

[Cruzen]

I just noticed where you live and now I know what's causing the problem. IT's COLD OUT THERE!!!!! Everything will shake at this time of year

My daughter spent much of her life in Lockport and now lives with her husband in Romeoville where he is a cop. He runs one of those DARE cop drag cars. If the problem persists I can put you in touch with him and he may be able to give you some good local leads.

I raced out at the Grundy County circle track when is was asphalt. I also ran several drag cars at U.S. 30 drag strip many. many, many years ago.

COLD, COLD, COLD!!!! Brrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr!

Keep warm,
Denny

[John Robinson]

Have you solved the problem yet?

My reason for asking is that I have just had the same problem with my 93. On the road it had a vibration that progressively got worse as the speed increased. At 100 the steering wheel shock so bad I could hardly hold onto it. After doing all the things I could with the tires I figured they must be bad. Not so here is the wild part what was happening was my Opti was only firing 7 cylinders and the vibration was the engine shacking the whole car with the misfire.

I am having the opti replaced and will let you know if the vibration is gone.