I dont know what it is, but my 86 GT has a wierd swaying while driving, its not constant.

it feels like the shocks, but they dont seem to feel gone if I get out of the car and try to wiggle the car.
kind of feels like the alignment changes.
ive tested all of the ball joints and tie rods, they are good.

it usually happens when coming out of a turn or long curve, it feels like it wants to turn outward.
example: when coming out of a left hand curve, while in the process of adjusting the wheel back to straight
the car's steering feedback goes loose for a split second, and seems to jet out to the right
(as if I turned that way but im not) forcing me to turn back into the curve.

it started an alarming fishtail out of nowhere on a long straight strip of road cruising at 60.

It sounds like your rear toe is out of alignment. Are you sure your rear tie rods are good?

Control arm bushings will feel that way too. Check the bushings and the bolts that run thru them. Uppers in the front would be worth looking into as well. If you hear a strange scrubbing noise when it happens, or even if you don't, check rear hubs. These are all things you can check quickly. It might not be super obvious. Look close. The smallest movement in these places will feel huge in the steering.

Agree on control arm bushings, but for the hell if it check your tire pressure. Mine doesn't like to be low; i get a little sway in the rear when hey get low.

When you checked the ball joints, was the rear supported by the frame or by the lower control arm? If you supported the car by the frame, you won't get a true indication of the ball joints. I had a very similar feel, almost like it would do a little butt-bump to one side. Turned out to be the ball joint.

I had one tire drop to about 20 psi and wow it felt like I was on a sheet of ice the way it was acting. tire didn't look that low.

My wheel bearings were loose and it caused Violent swaying at highway speeds.

quote Originally posted by ajarvis8: Agree on control arm bushings, but for the hell if it check your tire pressure. Mine doesn't like to be low; i get a little sway in the rear when hey get low.

It's easy to tell if it were a tire pressure problem.
If was an imbalance upfront, the steering wheel wouldn't be straight.
If it were in the rear then turning one way will feel more spongy than the other way.

Sounds like what happened with mine when there was too much rear toe in. It wasn't consistent and would wiggle the back end like crazy especially taking a gradual curve in the road with rutted pavement.

I'm planning on upgrading the bushings to poly in a little while, I'll inspect everything sometime next month.

How about engine and transmission mounts?

Also could bad cv axles cause anything with it?

I did a drive by feel home alignment when I first bought the car, and if anything I should have no toe angle.
And maybe it adjusted out a bit. All the ball joints are worn but not in bad condition.
Rear cradle bushings? Maybe the car is over exaggerating bump steer, the handling definitely doesn't feel anywhere near as tight as when I first got it.

Also check the motor mounts. My 84 got really bad a few years ago. It would feel like the the rear rear was trying to come around on me. As my shocks and struts were around ten years old I got KYB's for the front and rear. When the shop put them on they called me up and said I would have a nice handling car if I replaced the motor mounts. I had them do it and what a difference. The car is a blast to drive now.

It's probably the rear tie rods, not just the tie rod ends. Rodney Dickman has a set. Also, check the rear hubs as was mentioned. All the other suggestions were also valid, but I had the same problem, and this is what caused it. That, and I need better tires.

http://my.execpc.com/~rodney1/suspension/index.htm

Would motor mounts really affect that?

[This message has been edited by Stainless1911 (edited 12-29-2012).]

Yes the motor mounts can make the Fiero handle bad. My car got so bad that I didn't want to drive it. I drove across an expansion opening on an overpass at 75 MPH and the car tried to come around on me. It felt ten times worse than the slight bump steer I had. I was surprise to find it was the motor mounts, but that cured my problem. Handled like a new car with the new shocks and struts and good motor mounts. The car had around 212,000 miles on it when I had it done.

Motors mounts my not be his problem, but it is worth having them checked.

Thanks. Where do I get poly mounts for a Duke? I checked prothane and randy dickman, but all he had was for a V6.

quote Originally posted by johnt671: Motors mounts my not be his problem, but it is worth having them checked.

LOL, I know I have some BAD mounts.

the whole car clunks from the rubber being gone.

we will see what goes on after i replace them here sometime in january.

quote Originally posted by johnt671: Handled like a new car with the new shocks and struts and good motor mounts. .

Hmm! Wonder just how much effect those motor mounts had as opposed to the new suspension parts.

quote Originally posted by fierofool: Hmm! Wonder just how much effect those motor mounts had as opposed to the new suspension parts.

yes, lol. I wonder how my car will handle and feel like after I replace all of them.

Nice and solid. you'll be happy with it.

quote Originally posted by AL87: LOL, I know I have some BAD mounts. the whole car clunks from the rubber being gone. we will see what goes on after i replace them here sometime in january.

And you are seriously wondering why you have suspension issues?

And just a hint...when one motor mount goes bad..they all go bad..because one fails and puts extra strain on the others causing them to fail as well..

quote Originally posted by 87antuzzi: And you are seriously wondering why you have suspension issues?

*shrugs with hands up in air*

Here is another possible cause: http://rwhughe.oplink.net/U...heHood/BrokenSF.html

If you haven't fixed your bump-steer you need to. Suspend your engine, and drop just the cradle. Factory defect...pivot point of the tie rod anchors is min. 3" inboard of your control arm pivot points on the cradle. These should be in near perfect alignment as possible, or your rear wheels will take you all different directions...can be pretty spooky! Truckers tire ruts on the highway can really jerk you around. Here's what to do:

Die cut the tie rod anchor brackets off, flip them around and re-weld them them three inches toward the control arms, from the original anchor point. Be sure to mark your dimensions on the cradle to get them in the right place. Cut three inches off your threaded tie rod end that bolts to the anchor and re-thread it. Bolt it down to the new bracket position and torque per specs. Remount your cradle, and get it re-aligned and your in business. You can opt to purchase the bump-steer kit for about $700, but this only costs you the time to do it, and it's really easy, with a little cutting and welding, etc. This will make your car go down the highway straight as an arrow! The feeling of stability at highway speeds is priceless...lol! I was afraid to go over 70 before I fixed mine...now I have a hard time keeping it below 80. I've had my GT pegged and climbing with no problems, except for that state patrolman hiding behind the highway sign...;-)!

Guarantee: This will make you fall in love with your Fiero all over again!

[This message has been edited by hypo327 (edited 01-04-2013).]

I don't know from personal experience how the car handled after the shock and strut install, but when the shop test drove the car after they put them in they said the car was still wonky from the bad mounts. All I know is the car handled so much better when they were done.

I have just recently relocated the "Bump steer cause links" without doing any welding. I shortened the rods as listed above but, instead of rewelding the frame tab, I put a spacer outside of the frame tab and bolted my shortened arm to the new spacer. I haven't driven it yet, but I'm hoping for the best.

i want to say whatever it is, the bump steer has gotten worse since then, Im jacking this thing up tomorrow. and dropping the cradle anyways. to service the exhaust gaskets and do cv-axles, and replace the mounts.

I dropped the cradle out and found what the problem seems to have been.

everything was fine, the struts, ball joints, tie rods, everything had been replaced.

it was the top bolt on the engine mount bracket, it had come out and fallen off. also the small driveline shock got smashed.
any replacement for that?

Also I have great news, I broke off 3 header bolts at the head...

okay, I found my original thread. here.

I swapped my old 2.8 out, put my rebuilt one in, replaced all the mounts, replaced the CV axles.
did a little bit of fine tuning, and debugging.

this has been a pain in my side, the rear of the car sways out right every so often, mostly from my shift from 1st to 2nd with the auto trans on hard acceleration.
also sometimes at high cruising speeds on non-consistent roads. it seems to roll rather squishily when I snap the wheel left, as compared to when I snap the wheel right

everyones told me my tie-rods, or balljoints, or control arms are worn, i just jacked up the rear end and gave everything a strong shake. there isnt much moving, nothing I can tell by doing that... Im about to drop out the rear suspension assemblies and dismantle them to inspect everything piece by piece, since I cant find the culprit...

strut???

I had a similar problem years ago, and it was the inner tie rod bracket - it cracked and allowed movement. That was after many years of auto slaloms.

I would also swap on different tires, or switch corners to see if the problem changes. It could be tires.

Dave

Make sure you're not letting the suspension hang when the car is off the ground checking these things. I put the jack right by the ball joints so everything stays as it is when the car is being driven, just with the rubber off the ground. What you're looking for, most likely, isn't going to be any super noticable movement. I've had problems like this on a few fieros. One was a bolt that had rusted/worn and was about 1/16 inch narrower where it passed through the rear control arm mount. That allowed enough movement that I could feel the alignment change instantly when accelerating or decelerating or going into or coming out of a corner. It would shift from one extreme to the other. I spent a long time grabbing and shaking everything before I noticed the smallest movement at the base of the control arm. That car only had 30k on it. Another car was one rear hub. Another car had about 10psi in all the tires. Another had bad cradle mounts. I've heard some people say motor mounts will do this. A good alignment is very important but a good alignment shop is really hard to find in my experience. The front of the car has another set of potential problems but it sounds like you're confident it's in the rear. There are other things that can cause this sort of issue but these are what I have encountered so far. Keep up posted, good luck.

I had a very similar experience with my last 87. I could be going straight down a road and it would feel like the rear end would hop to one side for no apparent reason. I never got it figured out. That car got hit a few times and now it is on jack stands as a parts car. I'd really like to know what fixes yours.

I suspected the hubs more than anything. They can completely separate in two. I don't know if a wheel would fall off or if the caliper holds everything together but leaves it sloppy.

Jonathan

I had something that sounds similar. I would feel the car sway a little when going over a dip or other change that would compress the suspension. It would actually pull to one side and then pull back into line once the suspension was level again. Turns out the front sway bar bushings were shot and one side was tighter than the other. Replacing the sway bar bushings makes it tight as can be.

quote Originally posted by Ray_and_kevin: I had something that sounds similar. I would feel the car sway a little when going over a dip or other change that would compress the suspension. It would actually pull to one side and then pull back into line once the suspension was level again. Turns out the front sway bar bushings were shot and one side was tighter than the other. Replacing the sway bar bushings makes it tight as can be.

I thought for the longest time that my rear swaybar was part of the problem. I started a thread about it and was quickly told that couldn't be it. Maybe I was right. Thanks.

Jonathan