WTF!!! Car is all over the place when hitting a bump or on highway

erniet17

Member
Oct 4, 2005
124
1
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What's going on everyone? I have a 1993 Notch. When I bought the car I noticed that when I would hit a bump that the car would want to change lanes by itself. It also sways when I am on the highway. I thought that maybe it did that because the car was lowered quite a bit on the front so I bought new suspension parts. I just installed FRPP B-Springs, Tokico shocks/struts and the complete Energy Suspension kit. The car handles awesome but it still goes off to the sides when I hit a bump or get on the highway. What else could this be??? My steering wheel is pretty soft. Could it be the rack and pinion? I was reading other's posts with the same problem but they were mostly on 94-95 body style and they replaced a bearing that apparently my car doesn't have. Any ideas??? Thanks.
 
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sounds like you took your front swaybar out, i once knew a guy who did that, ran over an anthill in the middle of the freeway on the way to the dragstrip, with 3 other guys in the car. they never even found the wreckage...

did you put new cc plates in?
 
I also forgot to mention that I do not have caster/camber plates and I did get the car aligned. The drop on the B-springs is minimal. I installed the same shocks, struts and springs on my previous 93 GT and it drove perfectly. My brother now owns it and it is still driving perfectly.
 
My car did the exact same thing. Once I replaced the shot struts/shocks everything was 100% better.

Dunno what it could be for you... you seemed to have replaced everything that would be affecting bump steer.
 
I would check everything in the front and rear, suspension wise, and make sure everything is tied into the frame the way its supposed to be. Maybe you're just exaggerating, but the problems you are describing sound much more severe than any bump-steer problems I've ever had.

Chris
 
I got on the highway this morning and the car would try to change lanes by itself. I can let go of the steering wheel and it will drive straight but of all of a sudden it wants to go to the sides. I wish I was exaggerating! I can't drive next to another car because I am afraid I will going into their lane. I think that it might be the rack and pinion but I don't want to keep spending money and not fix it.
 
How much slack are in the tie rod joints and universal & flex joint steering shaft couplers?

The universal and flex joint steering shaft couplers can be inspected with the car parked on the ground. With the engine off, have a helper rock the steering wheel back and forth while you inspect the universal and flex joint steering shaft couplers for excessive slack. You'll need a sharp eye and a strong light to do a good job.

Support the car on jackstands with the jackstands placed as close to the wheel as possible. With the steering locked, have a helper try to move each front wheel just like it would move if you turned the steering wheel. While they are rocking the wheels, you are under the car watching for slack in the tie rods.

If the steering rack does not have excessive slack, have the alignment shop increase the caster to at least 3 degrees. Increasing the positive caster tends to reduce the tendency of the car to road wander.
 
wandering

bumb steer is one,,your caster reading could be to low also..high positive caster makes wheel stay tighter,,the older mustangs with manual sttering was set negitive on caster so you can steer easier,,you tires are next,,,2 different types of tires will also cause that problem,,,all 4 should match,,,i have noticed the wider the wheel the more you can feel tire differences..like coming up to a traffic lite and car pulls side to side when slowing down or on a major highway were truck traffic is heavy
 
I will check on it tomorrow and maybe take it to the mechanic as well. I do have drag radials on the rear but both tires up front are the same. I was told that since my tires are non-directional I can change them from left to right and right to left. Some say that might help. I will keep the site posted.
 
tires

switching tires side to side is a diagnostic step to see if tire is cause of a pull to one side? someone else did metion toe,,toe out will cause a wander ,,toe in being off normally doesnt wander cause the tires are fighting each other,,too understand this ,,your steering wheel controls mostly one wheel and the other follows,,when toed out they will wander,another way is try 2 different tires on the rear,,you say you have drs,,
 
The car did the same thing before I replaced all the suspension parts. I figured that it was because it was too low up in the front and maybe caused bumpsteer. I just aligned the car on Friday. I might go back and ask if they can recheck it.
 
I'd start with Maximum motorsports CC plates, a bump steer kit, and an alignment set for maximum positive caster. Stock CC plates just don't have enough adjustment for all situations. The positive caster will keep the car from following the ruts.

Don't discount tires as the problem either. 4 of the same brand and style are usually the best bet.
Also if the tires on the rear are in better condition than the fronts, that's bad too.
 
I might be looking into the cc plates but wouldn't I need a bumpsteer kit if the car was lowered 2" or more? The springs only lowered the car about .875 according to their specs. As far as the tires go I had 4 matching tires before I got the drag radials and it did the same thing. I just don't understand why my 1993 GT with the same exact suspension minus the polyurethane bushings didn't have this problem. I wondering if it is the rack. what are signs of a bad rack?