Hi all, i'm new here and am in need of some help.

I bought a 1990 XJ on craigslist for a really good deal and mostly for a project jeep.

The front was switched to 4.10 gears, and the back are still stock (I believe 3.55)

I've seen a lot of people talking about doing the ford 8.8 in the rear as an axle swap.

If i swapped just the axle in the rear with a ford 8.8, could I use 4wd? I'm new to how the axle's and 4wd work. Right now, 4wd doesn't work due to the gear ratios not matching.

Regearing is an option but seems like a timely project to do, I have a fully capable shop to work in.

I was planning on looking for a ford 8.8 axle for the rear, and would this fix my issue?

Thanks!

 

the only way you can run 4 wheel drive is if you have the same gearing in both axles. search the internet to see what ford explorers or rangers (I think) came with the 4.10 gears. I'd have to assume that you would have to look at something with a 4 cylinder. You could also look for an 8.25 that has the 4 banger in it for a rear axle with 4.10 gears.


hope this helped.

 

So would I need a rear axle with 4.10 gear ratio and that would allow me to run 4wd? If I understood correctly

 

The ranger is a inch shorter then the explorer is,The explorer 8.8 is not a bolt in it takes welding and a swap kit before it will bolt in.If you can weld and set up a axle with spring perches you can get a swap kit for this.The 8.8 is harder to find in a 4.10 most i have seen are a 3.73 gear so you can wait for a 4.10 or have the gears changed.And yes both axles front and rear have to have the same gear ratio in them.But before you do a axle swap do you have a dana 35 or the chrysler 8.25?If you have the chrysler 8.25 and can set up a rear end or have a friend that can would be better just to change the gears in that.If you have a dana 35 i would use it as a reason to swap rear ends.If you want a bolt in rear end now the 4 cylinder xjs used 4.10 gears stock you could grab a used rear end from one of those but make sure its the chrysler 8.25.

 

I would use a 97 up Chy 8.25 29 spline differential and have it re-geared before install. Its a direct bolt-in in your XJ and quite strong a lot less work and a proper fit.

 

And if you want disk brakes you could do a jy KJ swap at the same time.

 

So if I find a rear axle from a 4 cylinder xj, I could swap it in and that would work with the front axle, allowing me to use 4wd?

 

only if it's a Chrysler 8.25 axle, yes it would make it work

Don't use a ranger 8.8. They got 28 splines. Explorer 8.8 is 31 splines but need welding work to swap in.

U ll actually find explorer 8.8's in 4.10's very often than u would find a 4 cyl Cherokee with 4.10 gears.

 

Easiest is to look for 29-spline 8.25 with 4.10 gears, You can swap one of those in an afternoon in your driveway easily enough.

You can find a Ford 8.8 from an Explorer that will have 4.11 gears (close enough) and disc brakes already on it, but as said above you have to do some other work to it, and its not a perfect fit.

Another option is just have a shop install 4.10 gears in your existing axle. Not worth it for a Dana 35. Completely plausible if you have a C8.25 (your 1990 would be 27-spline, but you can upgrade to 29-spline parts at the same time as the upgrade, just have to buy the right carrier and new axle shafts). Definitely if you have the Dana 44.

 

I've fount in my research that there is almost no strength difference between the 29 spline 8.25 and the 44 once built. Only bad thing is the c-clips.

 

4.10 8.25 axle is easiest to swap in, but it is NOT easy to find. Let's clear that part up

 

8.8s with 4.10s are a dime a dozen. Get one with an open carrier so you can lock it. By the time you buy a 8.25, gears, master install kit, pay to have the gears set and disc brakes. Your looking at a minimum of $700. You could buy an 8.8 and swap kit for under $400 and have a much stronger axle and not need to use degree shims. You can install an 8.8 in a few hours. I did mine in about 8 hours with fully rebuilding it and welding the truss on.

 

If you are still running stock wheels keep in mind the 8.8 is a bit narrower than a stock XJ axle, slightly more than an inch. So with stock wheels and any tire larger than a 29 you take a chance of rubbing the leaf springs, not much of an issue with aftermarket wheels with better backspacing.

 

Which rear end do you have in it now ?Here is how to id which one you have https://www.cherokeeforum.com/f2/axle-info-148057/ if its a dana 35 i would swap it if its a chrysler 8.25 i would think about swapping your front axle to anything xj 91-99.I think it would be easier to find a front axle in 3.55 then a rear axle with a 4.10 in a junkyard.And how do you plan on using your jeep?If its just a daily driver that will never see off road really any stock rear axle even the dana 35 will be ok.

 

For the 8.8 to match your front axle you'll want a 95-01 explorer axle. Door code will be a 42 for an open carrier or a D2 for a limited slip. Heres a page to look at for the codes. http://therangerstation.com/tech_lib...le_codes.shtml