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Switching AOL to AUL


NAXJA Forum User
Toledo, OH
90 MJ Pioneer...4x4...

1.All right this has probably been asked 1000 times but... are there any good websites with pictures documenting the change of an MJ rear suspension to AUL? How much height can I expect...

2.Where can I get a decent leaf spring package of moderate cost- I might as well change them while I have the axle off. OR should I just add a leaf?

3.Do the XJ have a AUL setup????

4.Thoughts on matching the front in height??? New shock and spring package? I was probably going to fab my own brackets for the rear...to save some costs.

5.Any driveshaft concerns???

TIA- PRL hasta
I believe the proper acronyms are SOA and SUA.

Just did the SOA switch on a buddy's MJ last week. It's a pretty straightforward swap. I think it gave him about a 5 inch lift on the stock springs with no AAL.

He's using RE 4.5" coils with a 1" spacer. And yes, there will be driveshaft issues. He's gonna need to get his driveshafts modified.
the height for aul swap will be a little different depending on what axle you have. i just did mine with an xj d44 last week. i got about 5-5 1/2 in of lift. by the way xj's are aul. the other problem is the perches on an xj rear are about 1 1/2 inches overall wider. to do this swap correctly you should move your perches. i didn't move them on mine, and am now thinking it maybe a mistake, time will tell. as far as the shocks, i just cut the brackets off and moved them up, and put them both to the rear of the vehicle. for the front i used the RE 4 1/2 super flex set up, it sits pretty level. the rear drive shaft was not a problem since i had a d35, and switched to a d44, because the yoke is longer. and if i can give you one piece of advice that is to not unbolt the leaves, simple disconnect everything, take off the tires, and have a buddy help you slide the axle out from on top the leaves. this makes things very easy. hope this helps
Nah, not an idiot, just acronym impaired.

I agree with the above. It was really straightforward...cut and weld. The nice thing is that MJ's can re-use the spring plate/shock mount. Just try to pay attention to your DS angles and you'll be fine.


I did mine many many moons ago on an 87 so I may be a little rusty on specs, but I don't remember it being hard at all.

Good Luck!
you will get roughly 6 inches of lift with a simple spring over. pay attention to driveshaft angles, and change out the joints for good measure, they tend to self-destruct within a few hundred miles after you drastically change their operating angle. You will need no driveshaft mods if you swap to an axle with a longer pinion, like from a D35 to a D44. Even with leaving the same axle the driveshaft works but droop your suspension out all the way to make sure the slipyoke doesn't fall out of the t-case. shock mounts will need to be addressed. match the front with springs and spacers to get matching lift and either long-arms or drop-brackets or your ride quality will be CRAP.