Rear end feels loose

[cardudeusa]

I'm in the process of fixing up my brothers 87 coupe. When you accelerate the rear of the car sways to one direction, then when you shift gears, it sways back the other way and feels like the car is going to wreck. Also there's a clunking noise that I can't identify. I was thinking maybe it could be upper or lower control arm bushings? I put the car in the air and tried to visually inspect them but couldn't really tell anything. Any ideas? Thanks in advance.

 

[robo]

it's most likely the control arms. i had the same thing with a set of south side machine bars a few years ago. all the mounting holes were elongated and the car would move all over during acceleration and shifting.

start there.

 

[PINIT 141]

i have this same problem with my car. it pulls hard to the right when WOT in first then straightins up in second. i will be checking it out soon.

 

[BlackGT89]

Uh oh. Better check those torque boxes. If they are really torn it can be bad news.

 

[2000xp8]

Uh oh. Better check those torque boxes. If they are really torn it can be bad news.

Yup.
Really bad news.

 

[cardudeusa]

Uh oh. Better check those torque boxes. If they are really torn it can be bad news.

The car hasn't been raced or anything like that, just driven and not maintained, what do I look for when checking the torque boxes?

 

[2000xp8]

Look for bolt hole tears for the lower control arms.
Also pop out the back sets and make sure the uppers aren't tearing the floor out.

If the car hasn't had any type of aftermarket control arm on it, you might be lucky and just need a complete set of arms.
Usually stock rubber gives enough that it doesn't rip the boxes out.

 

[BlackGT89]

The car hasn't been raced or anything like that, just driven and not maintained, what do I look for when checking the torque boxes?

If you are near stock HP and haven't made a lot of passes with slicks you are probably okay. But when I hear of someone getting really sideways left and right under acceleration with a clunking noise it makes me think "torque boxes".

This link has a few pictures of torque box damage:

Torque Box Broke... - MustangForums.com

 

[cardudeusa]

Cool, thanks for all the info, I'll check into it.

 

[PINIT 141]

sorry cardudeuse for kinda jacking your thread.. i think i may have found my problem with my car. i looked all under the back of the car looking for signs of broken or torn torque boxs or any other rear end componets. i did find a small tear just to the left of the right side torque box. im thinking this was causing my problem. i got the welder out and welded it up and while i was under there i added a few more tach welds to the torque boxs. i took it for a test drive and all seemed fine. before this thread i had no idea what to look for. thanks guys.

 

[BlackGT89]

I actually need to reinforce my TB's soon also. I'm getting ready to install aftermarket lower control arms (and Ford Racing UCA's) and hopefully will step up the horsepower soon after that !

 

[cardudeusa]

sorry cardudeuse for kinda jacking your thread.. i think i may have found my problem with my car. i looked all under the back of the car looking for signs of broken or torn torque boxs or any other rear end componets. i did find a small tear just to the left of the right side torque box. im thinking this was causing my problem. i got the welder out and welded it up and while i was under there i added a few more tach welds to the torque boxs. i took it for a test drive and all seemed fine. before this thread i had no idea what to look for. thanks guys.

No worries, the pictures are helpful actually. I'm going to check on Thursday and see if my brothers car looks like that.