Ok....cant figure out what is going on due to my lack of knowledge. My front suspension is "BUMP STEERING" very bad. Also....at speeds around 55mph I have no vibration...but at 70mph its bad.

Car specs: 78,xxx miles , FE1, New OE Concepts Wheels A-Molds 17x9, 17x11

1. I know I need to have the wheels checked for balance.

2. Suspension:What causes this type of problem? Tie Rod Ends? Ball Joints? Shocks? Could it just be worn bushings, etc?

3. I have the perverbial "wobbly steering wheel" also...from it being used as a hand grip for those who cant get out of the C4. Would this be related to my problem. I know the fix for the column and have the kit already from the dealer.

I can turn a wrench but want to be headed in the right direction before I start throwing $$$ at it.

Any help greatly appreciated. Thanks....

 

For sure...get the tires balanced first!

 

Will do...but this problem predates the install of the new wheels!!!

 

Jack the front of the car up and see if the wheels "wiggle" in ANY direction... if they do, thats more than likely your problem. Could be bearings, ball joints, or both... don't know till you check.

 

How old/how many miles on the shocks?

 

Ok...I'll check the front for slop tonight....

The shocks are orig. stockers...

 

My car acted the sameway . I installed new shocks & the symptons disappeared. I was surprised that the shocks exerted that much improvement in steering wheel feel.

 

How long you been turning that wrench? Of course your shocks are shot. Your wheels are woppling all over the place. Got any flat spots on your front tires yet?

 

Bump steering can also be caused by suspension flex. I had this problem----at speed 70 mph, when I hit a slight bump, the car would steer in the direction of the bump.

The problem was fixed when I installed a five point shoulder harness bar. It tightened up the entire bump steer problem.

Good luck.

 

I purchased my 95 in 12/95 with 2300 miles. My car came with the base suspension with flacid Bilsteins. The front wallowed like an old Caddy and the front wheels would bounce off the ground over raised tar strips etc.

I replaced the Bilsteins with Koni Sports. This 100% cured the wallowing problem and 90% cured the wheel bouncing problem over raised bumps.

 

These gas shocks tend to stiffen with age, though at speed they tend to cause a 'floating' feeling in the suspension. Worn bushings tend to cause noises when they go, creaks and moans when going over bumps.

But vibrations at speed are likely the lower balljoints, assuming the balancing is right.

 

i'm experiencing surface dependent vibration around 65 on a second set of tires and new kyb's all round. i'm hoping to find cheap moog balljoints after confirming a drive shaft u joint upgrade, is there a cheaper alternative? maybe a full front end kit that works quality wise? any suggestions?

there must be a median alternative to moogs, that doesn't involve $70x4.

 

I bought the front end kit from Corvette Central, or was it mid america...
anyway...
It included upper and lower ball joints, and tie rod ends. Stuff fit perfectly, and works fine. I installed everything myself, and did so with the A-Arms still on the car. I've had them on my car for a few months now.
FWIW, Mine is only a weekend car, and I don't do any racing.

 

Thanks for all you guys help. I think I am going for the front end kit and then possibly shocks.

 

Good idea, but I think I'd reverse that order.

Larry
code5coupe

 

I never heard anything about gas shocks stiffening with age or that stiffened shocks cause floating at speed. The shock valving that Chevy specified for the Bilstein shocks on the base suspension of late model C4s sucked from the factory. My shocks were 2 months old and only had 2300 miles on them along with the rest of the car, and still the front end of my car would float like a cloud. Vibrations at speed are more likely a tire-wheel assembly balance problem or a bent wheel issue, than a lower balljoint issue. When lower balljoints go bad, they make clunking noises when you turn the steering wheel from left to right standing still and going over bumps (bad bushings can make these sounds also). In any case, guessing is not necessary because the lower ball joints have visual wear indicators, i.e., a protrusion that the grease fitting threads that recedes into the housing as the ball joint wears. When the ball joint reaches the end of its service life, the protrusion will be level or actually recessed below the surface of the housing.

 

You need to stick around here more then.

Bilsteins do stiffen with age, the ride becomes considerably harsher in firmness with extreme age. It doesnt make the car oscillate.

Vibration at speed is SO VERY COMMON in C4s that its not funny, and we get a thread here at least once per month on average on the issue, and invariably it tends to be a lower balljoint fix. I know that balancing is the first thing to check. I'm aware how balljoints should fail, and that they have wear indicators, but those are not always correct for these cars from experience.

 

I noticed that he used the term bump steer. To me that is indicative of the darty steering in the c4s. I have seen thread after thread on that. I started a thread a while back about the camber brace and whether that helped. I was looking for a fix. There were about 60 replies. Some people told me to "be a man and get used to owning a Corvette". Others had many ideas. A possible fix for that may be in a Corvette Fever article (available on the web) that showed using later model A arm spacers that let you put more caster in the car. I'm going to try this in a couple of months when I put on tires. From your avatar pic, it looks like your car probably is equiped with these spacers already, so it could be an alignment issue (if you are talking about bump steer).

 

Over inflated tires? When I changed my rims the shop put about 50 lbs of air in the front tires and the car was all over the place at higher speeds. I lowered the pressure and all is fine.

 

I have been using Bilstein shocks and struts (replacing ball joints, etc. and doing my own alignments) on cars before your were born, so don't lecture me about them (I installed Bilsteins on my Dad's 1976 530i and my 1979 Trans Am). I also know all about C4s and their inherent vibrations, as I've owned and driven my C4 for 11 years. Bilsteins and other dampening devices do not "stiffen" with age, they merely lose their dampening characteristics, thereby allowing wheel tramp, which is perceived as harshness or vibration. Obviously, you have never observed a car with a broken or extremely worn shock or strut riding down the highway with the wheel continuously oscillating up and down.

Tires, however, will become harsh as they wear, which is where your "stiffening" theory is probably originating.

In any event, unless you can confirm your shock "siffening" with age theory to me with before and after shock dyno results, it remains BS IMO. And yes, when a shock or strut wears out, the car will oscillate or wallow over bumps and dips as I clearly indicated.

If the ball joints pass a visual inspection, I would check the wheels and tires for out-of-spec radial and lateral run out with a dial indicator, before replacing the ball joints.

A read of the factory service manual is not a bad idea either.