1986 SE V6 "Fishtails" on right turns at higher speeds (Page 1/4)
ArthurPeale SEP 12, 03:58 PM
I picked up my SE last January. replaced most of the rear end, with a few exceptions. It's been a ton of fun to drive.

For the first year, I could hit the local on-ramp to our highway at 40 or faster without breaking a sweat, but suddenly the rear end fishtails a bit on RIGHT turns.

I haven't noticed it on left turns.

Bad bushings wouldn't surprise me, I'm in the process of rebuilding a spare set to swap out. But, what are some other things that could go wrong that I should look at?
Kitskaboodle SEP 12, 04:10 PM
Rear strut bolts tight?
This will cause fishtailing.

Alignment good?

Ball joints tight and ok?
Original or has yours been replaced?
Most aftermarket ones have nuts and bolts and they can loosen. Mine did and my car fishtailed wildly over 60-70+ mph.
Kit
Dennis LaGrua SEP 12, 05:16 PM
Had this problem early on and it was a bad alignment.

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cvxjet SEP 12, 07:33 PM
I would suggest first checking the alignment- just the camber on the left rear wheel could set this situation up....An alignment shop but also, I use a yardstick hanging vertically to make sure of gross alignment.

One very odd situation I had a few years back was; Coming home from work along a bridge/causeway, I noticed that when I accelerated the car would pull to one side, and when I decelerated it would pull the opposite- after checking everything (Including alignment) I noticed that one of the struts was leaking fluid.

I pulled it off and compressed it fully- and it did NOT return (Extend). It was a GR2 Gas strut, and had been modified for coil-overs...when the guy was cutting the original spring perch off, he cut a bit deep and that led to the leakage.

It still had some fluid in it- but the gas pressure was gone- which changed not only the way the shock..."Shocked" but changed the overall spring rate.

Check your struts for possible leakage- compress them and see if they still have gas pressure. (But first check your alignment)
theogre SEP 12, 08:28 PM
In short... any rear steer in Fiero is near always cause by bad parts and/or alignment.
Even if new suspension bushings etc... cradle bushing w/ torque strut can make rear steer problems as engine load changes.
See my Cave, Bump Steer

Check all suspension and cradle hardware since installing parts. Can be a bolt loose or broken since work was done.

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David Hambleton SEP 12, 09:19 PM
In 34 years of Fiero ownership, I've had a few instances where handling became a little 'squirrely' due to tire pressure differences.
Slow leaks might otherwise go unnoticed but can have a significant affect on handling at a certain point.
Frenchrafe SEP 13, 04:24 AM
Check camber angles and then alignment.
If either are off, or there is a big difference like -0.5° one side and -1.5° the other side on the camber, then the back end will dance!
My car is set with -0.5° camber on the rear and -1.0° camber on the front.
The rear alignment is dead ahead, ie no toe in or out.
The front is like 1mm toe out (measured at the wheel rims , 15" wheels).

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Luperman SEP 13, 06:23 AM
I had that same problem it turned out the the drivers rear control arm bushings were frozen solid, I changed both sides out and that fixed it
fierofool SEP 13, 08:15 AM
Check the ball joints. A common mistake when doing so is to lift the car by the rocker panel or the engine cradle. This puts a reverse load on the ball joint. It tries to pull the ball out of the socket. The car should be lifted by the lower control arm to simulate a loaded suspension so the ball joint is in its normal operating position.

Once it's lifted by the control arm, place a bar or other leverage device underneath the tire and while someone observes the lower ball joint lift and release the force against the tire. I went through this problem for months and found that the ball joint was bad. If you have a rear sway bar on the pre-88 models, expect to replace rear ball joints more often because th swaybar puts a reverse load on them when making turns and curves.
ArthurPeale SEP 13, 09:14 AM
All great suggestions, team!

I'd been leaning toward alignment, but dismissed it because it happened so suddenly. At the very least I should get it checked.

Ball joints are definitely possible, everything in the rear end was replaced EXCEPT them, because they were in really good shape.

I check tire pressure before every ride, so that's not likely.

Frozen bushings would not at all surprise me. It's a Northeast car. I'm in the process of removing parts from one car to refinish, to swap in when they're done, but it's slow going.

It just happened so suddenly, but cars be like that, am I right?