Rear Axle Swaps

[CT99XJ]

I'll be editing this list as I come across them with axles that are possible to swap in to replace the God-awful D35.

ChryCo 8.25- average strength, beefy axle tubes (same diameter as a D60). If you can source one from a Liberty, you can even set up rear discs.

AMC20- Common axle in FSJ Waggys. Usually paired with a D44 front, probably a smart idea to pick up both. Usually needs to be regeared as it almost always comes with 2.71s.

XJ D44- came in some of the early XJ's and MJs (Renix era) but was replaced with the ChryCo axle. One of the best swaps you can do for strength.

GM 8.5"- pretty much equivalent to the ChryCo, but slightly stronger because of the larger ring gear. Weakness is the tube welds to the diff housing, tubes are prone to spinning. Easy solution is to truss/lay some extra beads on the joint.

Ford 8.8- Found under everything from Exploders to Mustangs. Exploder width is ideal for XJ, slightly narrower (about .5" each side). VERY good axle swap. Requires some welding and modification but very strong and easy to find parts for.

I'm going to hold off on full-size axles until I have a decent list of them.

 

[CT99XJ]

Update to Ford 8.8 swap: With 30's or smaller, the diff housing will hit every blade of grass you drive over. This is the weak point of the 8.8. A good solution would be to weld up some form of diff skid.

 

[Underpowered]

mgiht want to add the exploder is the only real upgrade, as the ones in teh rangers and stangs were the weaker 27 spline version and not much of an upgrade over the d35. and they are a factory spring under so new perches must be welded on. 97+ also have disc brakes.

also may want to note that pre 1996 chrys. 8.25 were only 27 spline, was first available
in 1991. 1996+ were of teh 29 spline variety and arguably of equal strenght to the D44, but have better points such as wider availability and bigger axle tubes. the 27 spline version is a upgrade over the D35, but not much of one. the 8.25 was only available in Non ABS equiped XJ's, any XJ with ABS has a D35 under it stock.

and the d44 was available primarily in 1987 in XJ's with factory towing package, some but not all with towing got the D44. it was rumored in some up till 89, but not as common.

as for the GM 8.5 it is a Full size axle. cars and S-10's got the 7.5" version of the GM 10 bolt. known weak point is the factory locker the G80, or gov-lock.

 

[Underpowered]

also, a popular full size swap is a ford 9' and HP44 out of older ford F-150's. same side drop (drivers side) as jeeps. with proper upgrades both can be built into formidable axles for strength. upgrades can be found everywhere for both axles and are pretty easy to source from a junk yard near you

 

[CT99XJ]

the 8.25's were in fact available with ABS. It depends on the options the vehicle came with from the factory. 27- and 29-spline 8.25's do not have different size axle tubes, the only differences between the two are the shafts and spider gears. 8.8's are the same way. You can easily convert an 8.8 to a higher spline by replacing the spiders and shafts.

 

[Dave]

KJ axles are all 29 spline Corp 8.25 (You know that) The one difference is from 02-04 most were drum brakes (discs optional) Starting in 05 they all had discs standard (05-07 models). So if you are looking in salvage yards that's what you should find in the KJ's as far as rear axles.

As an aside 3.73 is the most common gears (in 3.7Lv6). Unless you come across the rare 4 cyl KJ made from 02-05 and then it will have 4:11 gears. (didn't notice what gears you had in your front diff)

Also, most are open but some might have the optional track loc so the carrier will be different.

Wouldn't it be lucky to find one with an ARB in it and OBA....haha

Just trying to help.

Dave

 

[SUPERD]

as for the GM 8.5 it is a Full size axle. cars and S-10's got the 7.5" version of the GM 10 bolt. known weak point is the factory locker the G80, or gov-lock.

also known as the "grenade locker" !

 

[CT99XJ]

8.5 isn't a full size axle... the one in my K1500 is the same width as my XJ axle.

 

[Dave]

Rob, have you narrowed it down to what you want yet, or are you still collecting info on all your options?

Dave

 

[Underpowered]

8.5 isn't a full size axle... the one in my K1500 is the same width as my XJ axle.

your k1500 is a Full size truck is it not? the 8.5 is a full size, the 7.5 is not.

 

[CT99XJ]

Whether it's a full-size or not, from stud to stud it's the same width as a ChryCo.

 

[CT99XJ]

Dave- At the moment I'm running a second ChryCo 8.25 that I picked up dirt cheap with an Aussie and Riddler diff cover, custom truss, and alloy shafts. If I end up going full-width down the road, I'm thinking D60's front and rear. If the ChryCo and D30 fail me, I'll work some magic and fit the twin 8.5's out of my K1500. They're already geared to 4.10 with ARB's.

 

[ZebraZJ]

actually any of the 2nd generation explorers will have the 8.8 with disc brakes. years are 1995-2001 with gear ratios from 3:55 to 4:10

Tim

 

[RumorsOFsurF]

Dave- At the moment I'm running a second ChryCo 8.25 that I picked up dirt cheap with an Aussie and Riddler diff cover, custom truss, and alloy shafts. If I end up going full-width down the road, I'm thinking D60's front and rear. If the ChryCo and D30 fail me, I'll work some magic and fit the twin 8.5's out of my K1500. They're already geared to 4.10 with ARB's.

I don't know how hard you are on your stuff, but I swapped a 27 spline 8.25" in to my YJ after grenading two pinions on two different D35's. It's been flawless ever since.

Good luck!