2007 GT Rear suspension concern?

[BM08]

So, then the problem is for sure related to one of those.

If you look at pictures of really any S197 Mustang - no matter how much it has been lowered - you will notice all rear wheels are pretty centered in the longitudinal direction of the wheel well opening. This does not change with a noticeable amount unless there is a cock-up with the LCA length or the LCA mounts.

Go through everything again, making sure to follow the correct mounting procedure. Check the lengths of the LCA’s and the UCA and compare them to stock. Pay attention to their orientation as they are not symmetrical.

I actually bought some bmr LCA AND adjustable panhard bar just because the LCA bushing is torn on the left side and I have an adjustable UCA But I think I adjusted it wrong

 

[Kev555]

If it were me I would strip that whole backend and start from scratch inspecting every bit as its rebuilt. too many cock ups and misalignments there, car must feel like shit on the road with the current problems. I had an accident damaged pickup once with a bent half shaft at the brake hub, It felt as if it wanted to put you thru the hedge every time it hit a bumpy part on the road.

 

[BM08]

If it were me I would strip that whole backend and start from scratch inspecting every bit as its rebuilt. too many cock ups and misalignments there, car must feel like shit on the road with the current problems. I had an accident damaged pickup once with a bent half shaft at the brake hub, It felt as if it wanted to put you thru the hedge every time it hit a bumpy part on the road.

Mines is whenever I let off the throttle on the highway the rear end wobbles

 

[Alatalo]

Mines is whenever I let off the throttle on the highway the rear end wobbles

So it wobbles under back torque but not under drive torque…? If everything was mounted correctly, one would assume there is some massive cock-up with squat angles, causing ”brake hop” rather than ”wheel hop”.

But then again, is everything mounted correctly…? Going through everything sounds inevitable. Check every possible length of the aftermarket parts and compare to the standard parts. Check that everything is straight. Even the rear axle and the front LCA mounts. Check that all of the bushings are in good condition. Re-assemble in the correct order with the correct torque and torque procedure.

 

[BM08]

So it wobbles under back torque but not under drive torque…? If everything was mounted correctly, one would assume there is some massive cock-up with squat angles, causing ”brake hop” rather than ”wheel hop”.

But then again, is everything mounted correctly…? Going through everything sounds inevitable. Check every possible length of the aftermarket parts and compare to the standard parts. Check that everything is straight. Even the rear axle and the front LCA mounts. Check that all of the bushings are in good condition. Re-assemble in the correct order with the correct torque and torque procedure.

Yea when I get home today that’s what I’m going to try to do

 

[Alatalo]

Yea when I get home today that’s what I’m going to try to do

Remember to torque everything with the car in ride position, i.e. standing on four wheels on flat ground, alternatively on jacks under the rear axle. Absolutely not with the body jacked up and the rear axle dangling under…

Especially in the case of rubber bushings, torn bushings is a direct outcome of tightening bolts with the suspension fully extended.

 

[BM08]

Hello I have an update first I want to thank everyone for their help and for the few who told to recheck every bolt when I went to change my control arms to the bmr ones I got I found the bolt that goes through the panhard bar to the bracket was loose once I tightened that and there car now doesn’t wobble anymore on the highway

 

[BM08]

But the wheel still isn’t centered I’m still looking for that issue I’m just glad the wobbling is finally gone

 

[GriffX]

But the wheel still isn’t centered I’m still looking for that issue I’m just glad the wobbling is finally gone

Tip, if you torque bolts at the suspension, make a line with a paint marker from the bolt to the chassis. Than you see a lose bolt immediately.

The car is lower on the left side, is this what you mean with centered?

 

[BM08]

Tip, if you torque bolts at the suspension, make a line with a paint marker from the bolt to the chassis. Than you see a lose bolt immediately.

The car is lower on the left side, is this what you mean with centered?

No it seems like the whole differential assembly kinda cross for example the left rear wheel is pushed forward and the right rear wheel is slightly pushed back

 

[BM08]

I also did notice that this side is a bit lower than the other side I know this car was hit from this side and whoever repaired it did a terrible job

 

[JC SSP]

Ahhh this makes much more sense. Car was in a wreck… it’s possible the rearend assembly is bent or the entire rear body of the car was knocked out of alignment…

Look for damage, kinked, pinched, compressed areas or wrinkles on the floor boards… measure the undercarriage at multiple key locations and see if there are any variations from one side to another.

 

[BM08]

That’s what I thought but the diff assembly looks like it was replaced a used one

 

[BM08]

It has the marking they put at junk yards

 

[Alatalo]

But the wheel still isn’t centered I’m still looking for that issue I’m just glad the wobbling is finally gone

If the car has been in a crash, it’s not unlikely that you are looking at a bent or misaligned body. It’s fully possible to repair or even change body panels without straightening the body.

Completely up to you, but after you have verified the springs, the lengths of the rear LCA’s and that everything is correctly mounted, I would try to take some longitudinal measurements and even cross measurements on the body itself. For instance:

1) What’s the distance from the front wheel opening to the rear wheel opening on each side of the car…?

2) What’s the distance from the front LCA mount to the rear LCA mount under each side of the car…?

3) What’s the cross measurement from the front LCA mount to the rear LCA mount diagonally under the car…?

You get the point. Try to figure out what the real problem is. If you really want to know, that is.