Degreeing axle perches on SOA

[Incommando]

I am swapping in an XJ 8.25 when I do the SOA on the MJ. What would those who have done this recommend for degreeing the new perches in comparison to the location of the stock XJ perches, if at all? I am getting the perches welded on to the axle before the install so the "sling it under the truck and measure before install" will not work in this case. I am using stock 2wd springs so the total lift should be around 4.5 or 5".

 

Any thoughts or experiences would be appreciated.

[mvusse]

With a stock style driveshaft the pinion angle needs to be parallel to the transfer case output.

 

http://www.4x4wire.com/tech/pinionangle/

[philbert001]

With a stock style driveshaft the pinion angle needs to be parallel to the transfer case output.

 

http://www.4x4wire.com/tech/pinionangle/

:agree:

[64 Cheyenne]

the "sling it under the truck and measure before install" will not work in this case.

 

Best thing I could suggest to do is keep the XJs angle, moved to the correct width.

 

Kind of hard to get an exact correct angle without putting the axle under the truck with a loaded suspension and then

 

measuring.

[johnnyc]

Don't use the XJ angle. A foot difference in wheelbase will result in a different pinion angle. If you weld the perches on beforehand without measuring, I can almost guarantee that you'll have to do it over again, unless you get super lucky.

 

When I did the SOA on my MJ, we took the original SUA MJ D44 out and put in the built D44 from my old XJ. We tried to set the perches up so that they were identical to the MJ D44 perches. Sure enough, the pinion angle was wrong and we had to do it all over again the proper way.

[mvusse]

When I went SOA I bolted everything together (perches NOT YET WELDED) with a bottle jack under the pinion. Used the bottle jack to get the pinion to where it needed to be and tack welded the perches (and shock mounts) into place.

 

I then unbolted everything, tossed the axle into the back of my XJ and drove to a local welding shop to have them permanently burned on.