I have a '99 V6 Mustang and the rear end feels either loose or just sloppy. I notice it most around corners, but sometimes over bumps, etc. The main thing I notice is when going around a tight corner, at the end of the corner when I straighten out the rear end moves horizontally too much. It feels unstable.

I've recently upgraded the gears, axle bearings and seals, but that hasn't seemed to fix the problem. Any ideas on what might cause this?

 

What will help that more than anything will be lower control arms. Basically what you are feeling loose is the rear axle suspension. The stock ones have fairly soft rubber bushings, along with weaker stamped steel pieces.

I highly recommend a good set of aftermarket arms. For a good set of street ones, Steeda, BMR, and UPR all make good solid pieces with poly urethane bushings which would be fine in your situation.

Also I would recommend a set of subframe connectors to go on your car. It will stiffen the chassis up considerablly and help the car feel more stable in turns.

 

Thanks Scott. Now the hard part. With 103K miles on it, I need to decide if I should fix it or if it's finally time to get an '06. I just recently had to fix the rear axle bearings and seals and the gear and pinion and those bearings were all shot, so I fixed it all. I'm a little worried at 103K what will be next.

 

Only 103K? My pony is running at 191K and it is a '99 also, I would say that you have more life in your car than you think, I mean after all it is a FORD right? Just putting in my $.02

 

I agree with Jim. 103 isnt to bad. With regular maintence and proper care, the car should easily double that

 

A panhard bar will eliminate 90% of what you feel! I had the same issue with my GT. I didn't like the excessive lateral movement in the rear. Especailly when exiting turns. My solution was to go with a Panhard bar. I went with the Kenny Brown components. I installed a KB panhard, new Upper and lower control arms, adjustable shocks, caster plus plates, super sub frame connectors, jacking rails, extreme matrix bracing, front shockbrace, rear shock brace, and 4 point brace.

Obviously I've done a bit more then you may want to do, but the difference I noticed with just the panhard was significant. Replacing the control arms and bushing will help some, but to fully eliminate the lateral movement, a panhard bar is the way to go.

Ask me any question you like. I have on my car what everyone has suggested so far!

 

Thanks everyone, I really appreciate the help! It looks like I'll be keeping her longer than maybe I anticipated....of course, I may still buy an '06 GT too. Just the good ole question of deciding what I can afford.