Centering the rear end... 9" and adjustable suspension. I have Qs.
03-22-2008, 09:54 PM
#1
12 Second Club
Thread Starter
iTrader: (4)
Join Date: Aug 2003
Location: NorCal
Posts: 1,618
Likes: 0
Received 0 Likes
on
0 Posts
Centering the rear end... 9" and adjustable suspension. I have Qs. Ok.. so Ive had my 9" in for some time now. Finally had weld in LCA brackets put in. I have BMR adj LCAs, adj PHR, SPOHN adj TA. All the the BMR stuff has poly ends and SPOHN TA has spherical ends and is a short type that mounts to the OEM cross brace location.
Today I was using a drive on rack at work to adjust my pinion angle after installing the weld in relo brackets.... and I had to adjust my LCAs because after the relo bracket install my wheels were pushed WAY back and throwing my pinion angle off, causing some major vibrations.
Anyways... here are my Qs:
1) Is there any advantage to having the rear OFF center? Right now my driver side tire sticks out about an inch or so more then my pass. side tire.
2) What places are best for measuring the centering of the rear end? Is it pretty much just pick a spot thats mirrored on each side and then adjust till center or?
3) Im starting to question my pinion angle adjusting capability. I know its supposed to be pretty straight forward but Im not sure. Right now my driveline is +1* and the face of the 9" is +4-5*... that means my actual pinion angle is 3-4*, correct? Thats where I should be according to what Ive read if you have poly end susp.
4) Right now on hard accel, normal accel, AND cruise on the freeway I am completely free of any vibration. Once I take my foot out of it and coast... I get a slight vibration. Is this a sign of pinion being off or is this my rod end SPOHN TA sending normal vibration into the car? Seriously.. I know a rod end TA will transfer vibration over stock TA and poly end TA... but I want to be sure.
5) Thanks in advance and any help is appreciated!
Today I was using a drive on rack at work to adjust my pinion angle after installing the weld in relo brackets.... and I had to adjust my LCAs because after the relo bracket install my wheels were pushed WAY back and throwing my pinion angle off, causing some major vibrations.
Anyways... here are my Qs:
1) Is there any advantage to having the rear OFF center? Right now my driver side tire sticks out about an inch or so more then my pass. side tire.
2) What places are best for measuring the centering of the rear end? Is it pretty much just pick a spot thats mirrored on each side and then adjust till center or?
3) Im starting to question my pinion angle adjusting capability. I know its supposed to be pretty straight forward but Im not sure. Right now my driveline is +1* and the face of the 9" is +4-5*... that means my actual pinion angle is 3-4*, correct? Thats where I should be according to what Ive read if you have poly end susp.
4) Right now on hard accel, normal accel, AND cruise on the freeway I am completely free of any vibration. Once I take my foot out of it and coast... I get a slight vibration. Is this a sign of pinion being off or is this my rod end SPOHN TA sending normal vibration into the car? Seriously.. I know a rod end TA will transfer vibration over stock TA and poly end TA... but I want to be sure.
5) Thanks in advance and any help is appreciated!
03-23-2008, 01:52 AM
#2
TECH Resident
iTrader: (31)
Join Date: Mar 2006
Location: Denton, Texas
Posts: 809
Likes: 0
Received 0 Likes
on
0 Posts
I do not have an aftermarket torque arm but after installing my 12 bolt
I took my car to an alignment shop
I told them to use locktight blue on the adjustable parts(control arms and panhard bar)
and they aligned the rear centered sideways and from front to back
It was damn near perfect when I got it back and majorly off spec when I took it in
I took my car to an alignment shop
I told them to use locktight blue on the adjustable parts(control arms and panhard bar)
and they aligned the rear centered sideways and from front to back
It was damn near perfect when I got it back and majorly off spec when I took it in