moving axle back

sorry guys if this has been covered before... flame on if needed [i tried searching... to no avail]

Im regearing to 4.56 this week or the next, the front will be getting a powertrax locker, and im thinking that i might need to step up the tire size soon [probably only to 33s, but BFG 32s only measure to 31 when aired to 20 psi and probably even lower when i run at 10-14, while trXus MTs run a full 33 at 14-30 psi plus they are better :rof: ]

anyway, ill be cutting my fenders soon to either: [a little fun with paint]






it doesn't really matter either way, i'll be cutting high enough that ill need to re-tub anyway, i just need some more room to slam down on after logs, and drops and such.

now, when i cut, [especially if i use the first picture] it will be pretty senseless to leave the tire so close the the front edge, so i was looking for a way to move it back a small amount [even an inch or so]. of course, i know the DS will have to be lengthened, thats no big deal.

i have heard that you can flip the leaf packs around, and the hole would be back further, i figured i'd ask here, im sure someone knows. [before i measure... its dark and wet]

otherwise, ill have to take them to a metal shop and have them each drilled out for the center pin then buy some steeper shims... ugh.

thanks in advance guys.

Travis [who, because of monetary situations at present, is upset about not being able to post in the off-topic and advanced fab sections... but notices the diminished presence of stupid in each of the previous forums]

If you only want to move it an inch, you can just get adjustable spring perches. IIRC flipping the pack gives you closer to ~4".

I know M.O.R.E. has them http://www.mountainoffroad.com/more.htm. They also have offset plates to be used with your stock perches.

drill new holes in the spring perch an inch forward? thats what ive been thinking of doing.

buzzbombxj said:

drill new holes in the spring perch an inch forward? thats what ive been thinking of doing.

Click to expand...

I was debating on suggesting this. My setup is actually similar. I am using full F-150 packs with the stock front mount, custom rear, and had to move my axle forward about 1.25" (The axle is about 1" farther back than stock with this combo). My stock perches (8.25) already had 3 holes in them, but 2 of them were square. Since I was using the larger packs that use larger centering pins, I was able to drill the holes out and use them. You also have to drill the spring plate for this to work.

The reason I didn't suggest this, is because this method isn't for everyone:
1. Your fitting a round peg in a square hole (assuming your perches are the same as mine, they used a couple styles over the years). If using the small stock centering pin, there won't be much contact.

2. Shim problems: Because of the length of the perches, a standard shim will no longer work because half of it would not be making contact. I ended up making custom shims for mine for now. However you could cut and re-weld the perches to get a proper angle if need be.

The new perches are long enough this isn't a problem, plus they are longer than stock so they help counter axle wrap.

I have run into the same issue of how to move the rear axle back. I came up with two options.

1) 4 link it and call it good. This option is expensive and requires a lot of fab.

2) Go to the junk yard and get some full sized leaf packs and built my own springs. Use the exsiting front XJ spring mounts and reinforce the rear bumper and mount shackles to the rear bumper.

It all comes down to time money and fab time. Here is a picture of the start of my axle move.

yea, that is similar to what i want to do. but:

1) 4 link is a great idea but OUT OF THE QUESTION monetarily. [metal, welder, etc]

2) dont have a rear bumper.



how bad do you guys think it would be 4 inches back if i flipped the springs and shimmed? the DS would have to be lengthened, but im at the point where i just want it done [for the time being].

TNT UBE's allow you to extend the wheel base about an 1" or so.

I use the UBEs and mounted the shackles to my cusom rear bumper. The bumper ties into the cage and there are two massive triangles holding those together also (tire carrier is mount in between too). It has held up fine. This is with a dodge/cummins 6bt powered XJ w/ Hi9 front 14bolt rear and 39" boggers.

BlackJax said:

I use the UBEs and mounted the shackles to my cusom rear bumper. The bumper ties into the cage and there are two massive triangles holding those together also (tire carrier is mount in between too). It has held up fine. This is with a dodge/cummins 6bt powered XJ w/ Hi9 front 14bolt rear and 39" boggers.

Click to expand...

Have any pictures of your shackle hangers?


Only think I have to add is Ive heard that when flipping the springs, you will have greater axle wrap due to the longer spring length in front. So plan on making a traction bar.

BlackJax said:

This is with a dodge/cummins 6bt powered XJ w/ Hi9 front 14bolt rear and 39" boggers.

Click to expand...

Got any pics of the rig?