Rear end feels like it wanders

I have rebuilt the front end, new Koni shocks, springs, A frames, and installed poly bushings. On the rear end I put in new Koni shocks, poly bushing on rear springs, and add a rear sway bar. I did not replace the rear springs as they appeared to be newer and in good condition.

The car was aligned and drives handles well and seems stable at lower speeds. Under acceleration the rear end feels like it is wandering around and is really noticeable, the higher the speed the more it feels like it is moving around. It is manageable but seems strange, any ideas what could be causing this? At steady highway speeds it is rock solid, just under acceleration (not the tires breaking loose).

One more thing, when the alignment was done the tech said he could not put in the proper chamber on the right hand side, he recommended a chassis shop that can look it over, it seems that shock towers over time can collapse making adjustment harder to obtain. Not sure if this can be cause or not.

Ron

 

I should have noted that I just put on a brand new set of Michelin Radials. From what I could gather the lower control arm needs to be pulled more towards the front end so the adjustable lower control arm mounting you are talking about might be the solution. I have an appointment this Friday at a chassis shop that has experience with this problem, I will let you know what they find out.

 

Good idea but the tires have about 20 miles on them. I checked the air pressure and all are at 30 psi which seem about right, but not sure.

 

I think that is a good idea, it is not that hard to do and may shed light on the problem.

Thanks for the tip,
Ron

 

The car appears to be fixed. I took it to a chassis place this morning and after they drove the car they said it was the adjustment on steering gear box. I was doubtful but after they worked on it for less than 5 minutes told be to take it for a spin and it was okay. They then rechecked the alignment and it was good too.

Under acceleration it is straight as an arrow, turns easier too. Being to tight any turn of the wheel would cause the car to move in that direction, so much of the wander was caused by me just holding on to the steering wheel.

I think the gear box is worn and probably needs to be replaced as the on center seems too loose. The wheel has about 15 degrees of play from one side to the other before you can feel the engagement, if that makes sense. The chassis place said it needed to be replaced if I did not like the play, they cautioned about rebuilds saying most are no better than what I have now. A place that rebuilds a lot of Mustangs recommended the Flaming River unit, says it works well. I will consider it over the next few weeks.

Anyway, for now it appears to be okay. Thanks for all the input it was really helpful.