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I am trying to install a quick performance 9" rear and after getting it in the car with everything snug it seems the springs are bending/bowing from the perch to the boot up top. It seems like the rear is too far back but I can't move the rear foward the LCA wouldn't allow it and the torque arm couldn't possibly be pushed in more. Its a 98' Camaro. The car is at stock ride height with stock springs. Adj torque arm, non adjustable LCA, non adjustable panhard. I need to throw this thing together it's been sitting for a while now but I cant figure out why it isn't sitting correctly. Any insight would be appreciated. Thanks.
Everything bolted up.
Last edited by Bspeck82; Mar 18, 2018 at 08:12 PM.
In the pictures is the weight resting on the rear or is it drooping? Have you set pinion angle?
The rear end is fully extended not being supported by a jack. If I jack the rear up as if it was lowered on the ground the problem gets worse. The spring will bow and hit the body.
Based on the pictures it looks like the LCA mounts are way off. Remove the springs and jack the axle to the bump stops and see if they hit in the middle of the tube.
Based on the pictures it looks like the LCA mounts are way off. Remove the springs and jack the axle to the bump stops and see if they hit in the middle of the tube.
i hope not they welded them on for me and can't be moved
If the pinion angle is off it could be enough to roll the rear over more to help line up the spring perches.
Ty for quick responses. I can place a jack under the left spring perch near the mount for the panhard and Jack the rear up it will roll over but the perch will still not be aligned the perch on the rear end is farther towards the back of the car then the top perch. This is what is causing this bow.
I'm not so sure we're on the same page so I'll leave it at this. Part of rear end placement is getting pinion angle close to where it needs to be before you try to install the springs. If you pull the springs and set the rear on jack stands at approximate ride height...then adjust pinion angle to see where that leaves your spring alignment. From the pictures it looks like its drooping and pinion angle is way off so the perches are rolled back to far.
I'm not there so I don't know if that the issue or not.
I'm not so sure we're on the same page so I'll leave it at this. Part of rear end placement is getting pinion angle close to where it needs to be before you try to install the springs. If you pull the springs and set the rear on jack stands at approximate ride height...then adjust pinion angle to see where that leaves your spring alignment. From the pictures it looks like its drooping and pinion angle is way off so the perches are rolled back to far.
I'm not there so I don't know if that the issue or not.
Yep, set the hub center to about 15.5" from fender and then set pinion angle to 3 degrees less than crankshaft angle. Then jack it all the way up and look where the bump stops hit just to check while it is easy.
I don't know what need you will have to be below the top LCA bolt hole with stock ride height, but as you move this down it can change things. You see how the holes arc forward as they go down? This is the try and adjust for the LCA pulling the axle forward so you don't need longer ones to keep the same wheel base on the steeper angle.
Yep, set the hub center to about 15.5" from fender and then set pinion angle to 3 degrees less than crankshaft angle. Then jack it all the way up and look where the bump stops hit just to check while it is easy.
I don't know what need you will have to be below the top LCA bolt hole with stock ride height, but as you move this down it can change things. You see how the holes arc forward as they go down? This is the try and adjust for the LCA pulling the axle forward so you don't need longer ones to keep the same wheel base on the steeper angle.
So I removed springs and jacked it up to right around ride height. It seems the perch on the housing sits 1" farther towards the rear of the car then the top perch on the body of the car. I will attach some more pictures below it also seems that the torque arm has about an additional one in of movement towards the front of the car that it can make but my non adjustable lower control arms won't allow the rear to move back or forwards anymore does this mean even at stock ride height that I may need adjustable lower control arms to correct the situation. Thanks for the help btw. The rear end the sitting straight The perch on the rear housing is about 1 inch too far back towards the rear of the car Torque arm has about 15/16 to 1 inch of room to move towards the front of the car this is with rear lower control arms installed rear lower control arms are not adjustable
It appears that the rear end has to physically move about one inch towards the front of the car. This means I might need to go buy ajustable lower control arms. Which is weird considering I was told that this should work with all stock suspension at stock ride height. And I am at stock ride height. Unless there is a bigger problem at hand such as the spring perches not being welded properly.... God forbid
What is your pinion angle compared to your crankshaft angle?
What is your wheelbase at ride height? You should get 101" from front hub center to rear hub center.
You might have to use the top bolt hole for the LCA to move that axle forward.
Okay, so that has an adapter that allows the torque arm to mount on the axle. Are the heim joints on that adjusted so that the flat where the torque arm mounts is square with the pinion? Really need to know what your pinion angle is verse you crankshaft angle to get any further.
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!!Need help!! with my 9" install 
