MJ SOA question

Swapping a D35 out of my 87 MJ for a D44 out of a XJ, is this a direct swap or do I have to relocate the spring perches? I have heard that the spring sets an inch and a half different. Thanks for any help.

The spring perches are in the wrong place and you're going to have to weld some new ones up; while the MJ is sprung-under, the XJ is a spring-over axle configuration. The perches themselves are a different center-center distance although I don't have those figures right now.

There's also a brake proportioning valve in the MJ that you're going to have to adapt to the XJ axle, but PM Eagle or some of the MJ owners to see if that's even needed.

The brakes will bolt right up, the rear proportioning valve is independant of the axle and there is still a single brake hose to the axle on both setups.

I just SOA my MJ and it was a nice compliment to the RE 5.5" coils in the front. You'll want to weld up new spring perches to make it work, and to get the proper pinion angle. You can also check out www.comancheclub.com/forums for info.

Shock mounts must be delt with. MJs and XJs have different setups. When I went SOA, I simply trimmed the stock MJ mounts a bit to clear the axle tube and sandwiched them between the leaf pack and axle. This puts the mounts in the same relative location to the upper mounts and allows use of the stock shocks. It necessitates a slightly longer grade-8 bolt to go down through the leafs to reach into the perch. It limits my up-travel by about 1" with stock flares (bumpstops are important here) and my down-travel by another inch or so. I also recommend buying a set of junkyard MJ leafs and adding a second main leaf (with the eyes cut off) to each side of your pack under the current main. This helps control the springwrap that is inherent with SOA and long flexy leafs. I can vouch that this setup worked great in Moab, Colorado mountain trails, RORP, The Badlands, the Lake Michigan sand dunes and the thousands of highway miles in between.
Jeep on!
--Pete