front end problems

[Deusxmachine]

The front end of my 90 coupe starts vibrating at @55 and get worse the faster i go. It shakes so bad its almost undrivable at 65 and up. The two alignment shops have both given me different answers and i want to know more about what could cause this problem before i get screwed. Any help you guys can give would be appreciated. Also i was wondering if the sport suspension package in the corvette central mag is worth the money and if it helps handleing, is there another place to get the same kit cheaper or better one availible. thanks for the help

 

[GeorgeT]

If it's as bad as that, you have either tires that are terribly out of balance or out of round, totally worn out shocks or suspension parts that are worn out. In reallty, it is probably a combination of these items. How many miles are on this car? If it is high mileage, get the tires balanced and trued (out of round tires can be balanced but still cause problems), replace the shocks and carefully inspect the suspension pieces for excess wear and loseness.

 

[Deusxmachine]

The car has about 70000 miles on it. I just bought new wheels not long ago and have already had them balanced. I also had it aligined when i first noticed the vibration. im thinking of just getting a front end rebuild kit and a poly bushing kit for the whole car. Anyone have opions on the sport suspension kit in corvette central, is there a way to get this kit direct. Also where would be the best place to get the ball joints and tierod ends

 

[jimq]

They shouldn't be able to do an alignment with worn front end parts. When we do an alignment and the ball joints or tie rods or whatever are worn and loose, we insist on repairs first.

You can't adjust loose parts and expect them to stay where you set them.

What kind of answers were you getting at the alignment shops and do you have the ability/tools to check the front for loose parts?

 

[86er]

I agree with Jimq

I had a car with front end trouble and they said they couldn't do the alignment until fixed. I forgot what it was.

Recently took the Vette to get aligned and they needed to add shims in order to do the alignment. They usually will tell you if somethings not right and wont hold the alignment.

Check your shocks and sometimes drive-shaft/u-joints can also cause car to vibrate after certain speeds.

 

[Deusxmachine]

First place i took it too did the alignment, they told me i had a bent rim. I was pretty mad as i had just purchased these wheels from hvydeez and they were pretty expensive. So before i shipped it back i double checked at another shop and they said the wheel was perfect and that my ball joints where worn. i wanted to ask you guys what you thought about it because all the tire and aligment shops in my area are basicaly crackhead operated. I have decent mechanical abilities and my dad and uncles are good too so i want do the work myself. Since im going to have it apart i would like to go ahead and do everything. Id like to get better handling while im at it. any body got any suggestions on the suspension kits out there thanks for all the help

 

[GeorgeT]

You can check for yourself to see if the wheel or tire is bent or out of round.

Simply jack up the car and slowly spin the wheel. While it is turning, hold a pencil close to the lip of the wheel, as close as you can and barley touching the rim: you will see if the rim is true if the gap between the pencil and rim stays constant. If the gap widens and narrows as the wheel spins, it is not true. Do the same with the tire on the tread to see if the tire is okay.

 

[jimq]

You can also check your ball joints very easily with no fancy tools. If you can get the car up in the air, so that the tire is off the ground, and have somebody hold the steering wheel tight (it works best to lock the ignition and hold it against the stop) grab the tire at 3:00 and 9:00 and move it from side to side. If there is a lot of movement and you hear any noises you may have steering linkage play. Most likely a tie rod. It's also possible a worn ball joint will give you play from side to side.

Grab the tire at 6:00 and 12:00 and try to move the top of the tire in and out. If there is a lot of play that way you may have some ball joint problems (could also be wheel bearing looseness).

If you do have play and you can make the car secure in the air so that you can be safely under it, (!!!) have a helper move the tire repeatedly back and forth each way while you look for the source of the noise. You would probably be able to hold a tie rod and make the noise stop.

An out of balance rim tire or driveshaft is more likely to give you a bad vibration at 55 or 60 mph or whatever than a ball joint. If you have your old rims/tires try swapping one and see if the vibration goes away?

sorry for the long post, hope it helped

 

[jsinga]

If it doesn't shake until 55mph it is usually a balance problem.
I have over 200k miles on upper ball joints that SHOW NO WEAR
The lower ball joints on many years have a ridge on the zerk, GM says they are OK until the ridge receedes up inside the ball joint.
I got over 150K out of my 87's and they didn't need replacement!!!
The half shaft u-joints and wheel bearings are another story. Find a shop manual and check the wheel bearing end play. If they are worn out (you are in the window) you can get the shakes from them. Half shaft u-joints last about the same. You will never find a tire shop who can find a problem with them unless they will speed balance the rear tires ON THE CAR!
Check the tire runout visually and then look for a bearing or u-joint problem.
Find the problem before you start throwing money at the problem.

Good luck,

JS