8 3/4 pinion angle setting

[cherokeechief79]

Were doing a usct spring relocation on my sons 68 barracuda.
It will also have the inner wheelwells widened.
We were going to tackle it ourselves but a friend has offered to do it and he has a plasma cutter and a good welder.
The axle we have has been narrowed 3 inches per side and has axles in it but just a dummy centersection with no gears or pinion.
Can he set the pinion angle ok like this or will we need to get a loaded centersection in it?
Its got superstock springs and he wants the back end raised for big tires.
We drilled a new hole in the front spring mounts that moves the rear back 1 inch to help center the tire.

 

[crackedback]

To do it right the rear should be loaded at expected weight and on the ground

 

[33IMP]

It might be easier with the center out. He can use the face of the housing just as easy as the yoke.
I would expect to check it after it's all together and has weight on it.
Mine has the rear moved back an inch, super stock springs, and 2 1/2° wedges to get the pinion angle where I want it (5° down).

 

[cherokeechief79]

thanks..........with the springs back an inch how did the rear shacle look?do you have any pix of how the wheel is centered?

 

[crackedback]

As a reference with the perches level as if installed in car, the pinion was 5* up on factory A body 8.75's

Will that be correct for your deal, unlikely.

 

[cherokeechief79]

i think our car will be up high enough in the rear so the gas tank isnt a problem.
i just watched an episode of dead dodge garage and it look like maybe the shocks will be a problem.
i dont have the shock tabs welded on the rear yet so maybe i can move them somewhere better.

 

[cpearce]

As a reference with the perches level as if installed in car, the pinion was 5* up on factory A body 8.75's

Will that be correct for your deal, unlikely.

The pinion will be 5 degrees down, if perches level.

 

[crackedback]

The pinion will be 5 degrees down, if perches level.

Not sure what that has to do with how the factory installed the perches on 8.75 rears

A-body pinion-to-perch angle is 5 degrees up. This is NOT pinion angle because the springs are not parallel to the transmission.

If the rest of the drivetrain angles are stock, these dimensions will yield a 2 degree negative pinion angle once the housing is installed.

 

[mopowers]

Yep - the housing itself positions the pinion 5* up relative to the spring perches. Dr Diff (and others) have confirmed that many times on these sites.

 

[cpearce]

Not sure what that has to do with how the factory installed the perches on 8.75 rears

A-body pinion-to-perch angle is 5 degrees up. This is NOT pinion angle because the springs are not parallel to the transmission.

If the rest of the drivetrain angles are stock, these dimensions will yield a 2 degree negative pinion angle once the housing is installed.

Yep - the housing itself positions the pinion 5* up relative to the spring perches. Dr Diff (and others) have confirmed that many times on these sites.

My apologies, Guys. I had it right in my head, wrong when I wrote it. You guys are correct.

 

[33IMP]

thanks..........with the springs back an inch how did the rear shacle look?do you have any pix of how the wheel is centered?

Mine is a 62 b-body. The shocks were no problem with interference, the rear shackle has a bit more angle than stock, but it's the correct angle so it's no concern to me.
I used the Mopar performance front hangers and drilled the front spring mount location where I wanted it, with the ss springs.

The axle is centered up in the wheelwell, much better than stock. There's room for a 9x30 slick now.

 

[cherokeechief79]

perfect! thank you guys so much for the info and pix.
thats just what i was looking for