Swapping the axles on XJ and MJ

I've decided to go a different direction and turn the XJ back to a stocker for my DD. It's still a '98 with not too many miles on it, and I've taken pretty good care of it. I found a '88 MJ with a salvage title that'll make a great trail beater, and I've decided to get it and swap the suspension componants off the XJ onto it.

I'm getting new shocks so I know those will be okay.

I'm going to start a build thread as soon as I buy the thing, but I wanted to make sure I won't hit any huge headaches first.

XJ:
Front: Dana 30, 4:56, open, coil
Rear: Chry 8.25, 4:56, detroit, leaf (SOA)

MJ:
Font: Dana 30, 3.07, open, coil
Rear: Dana 35, 3.07, open, leaf (SUA)

The plan is to pull axles off both vehicles and swap them. I know I'll need new shocks for both vehicles as the XJ ones won't fit the MJ, and the MJ's shocks are so old I don't want to DD them.

I know we'll have to reweld the spring perches on the MJ's Dana 35 to bring it SOA for the XJ. My XJ didn't have ABS to begin with so no problems there.

Do you foresee any problems with this idea? Just want to make sure we're seeing it correctly before we start.

Sounds good to me. DS may need to be lengthened/shortened though.

The MJ has the disconnect axle. You will either need to shim the shift collar onto both shafts, or swap in 1 piece shafts. The MJ has an SUA axle, and will not bolt into the XJ. You will need new spring perches for the axle, and they will need to be welded on. Now for the MJ, the front XJ axle will bolt in. The rear axle will need new perches aswell, because the width of the perches on the MJ differes from the XJ. Then you can pretty much just put in the axles, and be good to go. The rear XJ leaves will NOT fit on the MJ, but if you go SOA, you wont need them.

Good luck!

EDIT: I just finishded reading your post, and realized you knew that. i r smart!!

We actually found a nearly new Dana 35 that won't require any modification to fit in the XJ. So that is good to go.

Why won't the XJ leaves fit in the MJ? It'll need new perches or what is the problem? Can you modify them to fit it? This is going to be trail only.

darwin said:

Why won't the XJ leaves fit in the MJ?

Click to expand...

mj leafs = longer (eye to eye)

...so the xj leafs are shorter

If you have aftermarket leaf springs, you can sell them and get some money to put into the MJ. An SOA on an MJ will net about 5-6 inches of lift.

And yes, the XJ leavs are shorter and will not fit the MJ properly.

I've got a set of 4.11 geared XJ axles under my MJ. In fact the front has had two different XJ axles due to an unfortunate incident involving unexpected airtime.

The front bolted right up. I bought a 4.5" XJ lift which had front LCAs, front springs, trackbar bracket, and 4 shocks. In the rear I did an SOA. I also moved the shock mounts up to the middle (vertically) of the axle which let me use the XJ 4.5" lift shocks that came with the kit. You have to move the spring perches no matter what since they are spaced differently side-side than the XJ. Total lift from previous was 5" in front and 5.5" in back. It sits pretty level since I think the stock springs in the back have sagged about 1/2".

In your case, I think you'll just need to cap off the vacumn lines. Actually you probably need to connect two of them so the 4wd light works. Or replace the xfer case vacumn switch with the electrical one from the newer xfer case.