The suspension mystery continues, and I don't know where to go from here. (Page 5/6)
Threedog AUG 15, 11:06 AM
The wheels are absolutely moving in and out. It’s bouncing back and forth..

The cradle is in perfect shape, it just got powdercoated(didn’t have rust at all before). We removed the deck lid before driving, the brand new poly mounts on the 3800 mounts are making sure that the engine isn’t moving at all..
cmechmann AUG 15, 11:20 AM
Looking at the video. The reaction is too slow per tire rotation to be axle. Looked like you had toe in on acceleration then toe out when you let up/shift.
If you don't have any obvious worn parts, look at rear lower control arm bushings too soft. Rear tie rod ends should be checked at ride height. On a set of turn plates. Or tire on trash bag works well too. Real easy to miss. Also without a good quality ratchet wrench, getting the exhaust out of the way, or having the subframe down, it is hard to make sure the inner tie rod mounts are tightened right.
Threedog AUG 15, 01:13 PM

quote
Originally posted by cmechmann:

Looking at the video. The reaction is too slow per tire rotation to be axle. Looked like you had toe in on acceleration then toe out when you let up/shift.
If you don't have any obvious worn parts, look at rear lower control arm bushings too soft. Rear tie rod ends should be checked at ride height. On a set of turn plates. Or tire on trash bag works well too. Real easy to miss. Also without a good quality ratchet wrench, getting the exhaust out of the way, or having the subframe down, it is hard to make sure the inner tie rod mounts are tightened right.




I think you are dead on about the toe issue.


The cradle mounts and a arm mounts are poly and brand new. The rear tie rods are new from Rodney Dickman and I followed all of his instructions on their install (including the funky washers you have to bend).


The wheels are straight and the rods were tightened with all four wheels on the ground.

However, this is what it looks like in the air...
Threedog AUG 15, 01:14 PM
This is what it looks like on the ground
IMSA GT AUG 15, 02:48 PM
That's 100% wrong. Any way you can stick your cell phone in the right rear wheel well and snap a few photos like this:


I'd like to see the arm position as well as the tie rod position. There's definitely an angle problem as if some parts have been installed incorrectly. Also let us know if you take the photo with the car in the air or on the ground.


Edit to add.......I just jacked my 87 in the air and the wheels are almost perfectly aligned. Something is definitely wrong with your rear suspension.

[This message has been edited by IMSA GT (edited 08-15-2020).]

Patrick AUG 15, 04:02 PM

quote
Originally posted by IMSA GT:

That's 100% wrong.

I just jacked my 87 in the air and the wheels are almost perfectly aligned. Something is definitely wrong with your rear suspension.



I agree. I've jacked the rear end up on a lot of different Fieros, and have never noticed the toe in/out changing to that extreme degree.

[This message has been edited by Patrick (edited 08-15-2020).]

Threedog AUG 15, 06:51 PM
So, the car is slightly lowered (an inch about) if that matters.

I won’t be back home till Monday evening so I’ll take a picture then.


That being said, I have replaced a few rear tie rods and messed with the back suspension before and nothing seems out of place, but we will see on Monday when I can take more pictures.

Part of me is wondering if I reversed the a arms or something when I put it back together...
cmechmann AUG 15, 07:48 PM
I need to clear one thing up. What I trying to explain, was those tie rod ends should be checked for play/wear at normal right height, I have had those type inner tie rod ends not show movement when the suspension is hanging unloaded. Only to show movement when at normal height.
Your issue is much worse than a worn part.
Yes reversed control arms could cause this. But I thought they were fairly symmetrical. Look to see if the stop bracket on the control arms match up to the stops on the spindles. If I remember to, I'll look under mine tomorrow.
IMSA GT AUG 15, 08:03 PM

quote
Originally posted by Threedog:


Part of me is wondering if I reversed the a arms or something when I put it back together...



I was wondering the same. If I remember, the arms have either a L,R or LH,RH stamped on them.
ltlfrari AUG 16, 08:55 AM

quote
Originally posted by IMSA GT:


I was wondering the same. If I remember, the arms have either a L,R or LH,RH stamped on them.



Yes, Also there's a tab at he end. The longer ear goes towards the rear I believe (picture stolen from another thread).

[This message has been edited by ltlfrari (edited 08-16-2020).]