Axle Swap Advice

[HoneyBadgerXJ]

Hey Everyone. So I'm planning a month long overland trip through Alaska with some friends next summer and I've been thinking about axle upgrades. I'm going to be running 33's and have been considering maybe doing a rear DANA 44 swap and just beefing up my front stock Dana 30 with a sleeve kit, c gussets, and maybe a truss? My rig is a 96 Jeep Cherokee with currently stock front Dana 30 and rear Chrysler 8.25 axles. My question is, is all this even necessary or am I getting ahead of myself? I'm not expecting anything like intense rock crawling or anything (is that even a thing in Alaska?). Maybe some mud, water crossings, off the beaten path stuff. We don't have an official route planned out yet, and I'm not expecting anything crazy. I just want to be prepared and make sure my setup will make it the duration of the trip. Thanks guys.

 

[v_man]

If you're only going to run 33's then I think you're money is better spent elsewhere than in your axles. You can also manage potential damage to axles through careful driving, not getting too crazy on the rocks, going easy on the skinny pedal when you are wheeling.

Many just bring extra shafts, u joints, on the trip with you, those components would likely break before anything in the diff.

 

[HoneyBadgerXJ]

If you're only going to run 33's then I think you're money is better spent elsewhere than in your axles. You can also manage potential damage to axles through careful driving, not getting too crazy on the rocks, going easy on the skinny pedal when you are wheeling.

Many just bring extra shafts, u joints, on the trip with you, those components would likely break before anything in the diff.

Thanks for the input. I was kind of thinking along the same lines. I know that some people ave run up to 35's on their stock axles. I suppose I'll just stick with lockers and call it good.

 

[36degreesNorth]

The 8.25 is a good axle and a 44 that will fit a Cherokee isn't much of an upgrade. For the 30 up front you have the high pinion but small u-joints (the first failure point on a D30) get some good axle shafts for a TJ (will have the bigger u joints) and keep your stocks as a spares. Biggest thing is keep it simple and low 33s will fit on 3 inches of lift with cut fenders

 

[HoneyBadgerXJ]

The 8.25 is a good axle and a 44 that will fit a Cherokee isn't much of an upgrade. For the 30 up front you have the high pinion but small u-joints (the first failure point on a D30) get some good axle shafts for a TJ (will have the bigger u joints) and keep your stocks as a spares. Biggest thing is keep it simple and low 33s will fit on 3 inches of lift with cut fenders

Why do you say to keep it low?

 

[36degreesNorth]

Why do you say to keep it low?

With the wight of the over landing gear you don't want to be so tall that it becomes tippy. Also with the short arm front link system in the Jeep taller lifts can equal binding and loss of travel. Long arm replacements systems get expensive quick

 

[HoneyBadgerXJ]

With the wight of the over landing gear you don't want to be so tall that it becomes tippy. Also with the short arm front link system in the Jeep taller lifts can equal binding and loss of travel. Long arm replacements systems get expensive quick

Good point. Thanks for the help

 

[Anak]

On a '96 the U-joints are not so small. I think '96 is the first year of the larger U-joints on the XJ.

If you want to do any upgrades, like lockers, consider stepping up to larger axle shafts.

First step should be to figure out which axle shafts you have in your 8.25. In '96 Chrysler made the change from 27 spline to 29 spline. If your build date (look at the sticker inside the driver's door) is late in the production year you might have 29 spline shafts. You can get a dealership to check if you take them your VIN. Odds are you have 27 spline shafts, but find out for certain.

A Chrysler 8.25 with 29 spline shafts is getting pretty close to the same strength as a Dana 44. If you have 27 spline shafts and are thinking about adding a locker you have the opportunity to step up to 29 spline shafts. The carrier is what matters. Make your choice at the time you order a locker.

Similarly you can step up to 30 spline shafts in the Dana 30. Again, it is the carrier that matters, so if you are planning to order a locker you might want to look into getting 30 spline shafts.

Along with these changes you can fret over gear ratios as well. For 33s you might want to move up to 4.10 gears.

But for the trip you have described you are probably fine with stock components in good condition. "Good condition" is the important qualifier there. If no one has replaced the U-joints, or even maintained the gear oil, in your old axles then it is anybody's guess as to how well it will hold up. And that applies to pretty much the entire vehicle. Do a couple of 500 mile days first just to make sure you aren't pushing the limits on any number of components. In other words, find your weak links on more forgiving terms.

 

[HoneyBadgerXJ]

On a '96 the U-joints are not so small. I think '96 is the first year of the larger U-joints on the XJ.

A Chrysler 8.25 with 29 spline shafts is getting pretty close to the same strength as a Dana 44. If you have 27 spline shafts and are thinking about adding a locker you have the opportunity to step up to 29 spline shafts. The carrier is what matters. Make your choice at the time you order a locker.

Similarly you can step up to 30 spline shafts in the Dana 30. Again, it is the carrier that matters, so if you are planning to order a locker you might want to look into getting 30 spline shafts.

So a couple of questions with that.
1) By changing the axle shafts to a different spline, will I have to make any changes to the carrier or spider gears or anything like that? Or should everything still match up?

2) You said that the carrier is what matters. What do you exactly mean by that? Is there a swap/upgrade I should do with the carrier?

 

[Anak]

The axle shafts have to match the carrier.

You cannot change to different spline counts without changing the carrier.

If you are thinking about a locker, and thus may be replacing the carrier, then it is worth considering making a change in spline count.

If you are considering an ARB or Ox locker you can order them in either of the spline counts I mentioned. On the other hand, if you are thinking of getting a lunch box locker (retain your existing carrier, but replace its internal components) then you cannot make a change in spline count. The carrier will not accept the larger axles.

The carrier dictates the spline count.

 

[HoneyBadgerXJ]

Okay cool, so just to make sure I understand. If I get an ARB, it will replace the carrier, therefore allowing me to get 29 spline shafts, so long as the ARB is for 29 splines. The ARB is what I was planning on getting and I found some Yukon shafts, so from what I understand, I should be all set with that. I'm also regeared to 4.10 already so I'm good to go on that front.

 

[Anak]

Correct.

Don't be surprised if there are some complications in moving gears over from one carrier to another. New gears are generally preferred. You might end up with some noise.

 

[HoneyBadgerXJ]

Don't be surprised if there are some complications in moving gears over from one carrier to another. New gears are generally preferred. You might end up with some noise.

I'll be sure to keep that in mind as it comes time to get the work done. Thank you for all the help.

 

[smritte]

Good info there.
Ive done quite a bit of rock crawling over the years. I know your not going to do that but, here's a little more insight. Ill just put down basics.
My 80 cj7, 33" mud terrains, V8 eng, stock corp rear, dana 30 front, detroit lockers. up graded axle shafts. Wheeled it hard, eventually bent the rear axle and broke a few u joints. 04 tj, dana 44's molly axles, sleeved housings, arb's, 35's and now 37's. Didn't beat it as hard but its a lot heavier. Broke a u joint.
Bottom line is, both vehicles would be over kill for what you want to do and had similar axle mod's to what you originally posted. Except for the V8, the cj, is pretty close to your rig's specs in the way of weight and axle.

My third vehicle was a 91 Cherokee with a small lift and 32's. All stock. bought it with 75k and sold it with 190k. This was my daily driver and desert exploring rig. No lockers, no axle upgrades, no winch or heavy bumpers. 2 flat tires over the 7 years I owned it. Drove dirt roads, sand wash's mild snow and mud and if a small rock section was in the way, drove over that.

What you should be looking at is your total vehicle weight and whether or not your going to tow. Most people lift their vehicle's, put a bunch of money into gears and lockers but, overlook what their causing. Heat. You said you wanted to run 33's and an ARB or two. Upgrade your axle shafts (i prefer chrome moly), new u-joints and consider 4.56-4.88 gears. (Search out gear ratio calculators.) You need to keep the vehicle in the proper RPM range. With the extra weight and tire size you need to bring the RPM a little higher otherwise you creating extra heat and load on engine and transmission.

Now that you dropped a couple thousand on your axles, hows your trans? I'm assuming your running an automatic. If its in good shape put a nice big trans cooler on and service it. How old is your cooling system? Make sure that's in good shape too. The trans and eng cooling systems are where I've watched most people have issues. If you do the axles correctly, with good parts, you wont break anything. The only mod's my Cherokee had was a nice trans cooler, trans temp gauge and better radiator. With the 4.10's and 32's it did bog a bit on hills. If I kept it i would have re geared it.

It sounds like your on your way to a nice build any way you choose to do it.

Scott

 

[HoneyBadgerXJ]

Good info there.
Ive done quite a bit of rock crawling over the years. I know your not going to do that but, here's a little more insight. Ill just put down basics.
My 80 cj7, 33" mud terrains, V8 eng, stock corp rear, dana 30 front, detroit lockers. up graded axle shafts. Wheeled it hard, eventually bent the rear axle and broke a few u joints. 04 tj, dana 44's molly axles, sleeved housings, arb's, 35's and now 37's. Didn't beat it as hard but its a lot heavier. Broke a u joint.
Bottom line is, both vehicles would be over kill for what you want to do and had similar axle mod's to what you originally posted. Except for the V8, the cj, is pretty close to your rig's specs in the way of weight and axle.

Thanks for all that info. That helps me put into perspective what I should expect to need.

What you should be looking at is your total vehicle weight and whether or not your going to tow. Most people lift their vehicle's, put a bunch of money into gears and lockers but, overlook what their causing. Heat. You said you wanted to run 33's and an ARB or two. Upgrade your axle shafts (i prefer chrome moly), new u-joints and consider 4.56-4.88 gears. (Search out gear ratio calculators.) You need to keep the vehicle in the proper RPM range. With the extra weight and tire size you need to bring the RPM a little higher otherwise you creating extra heat and load on engine and transmission.

The axle shafts and u-joints are definitely on the list, however I hadn't considered re-gearing again. I was thinking that a 4.10 ratio would be just fine on 33s, but now looking at the ratio charts, it seems it might be a little bit lacking. 4.10s on 31s at a monster set up for me, so I had assumed 33s would just even it out a bit. Thanks for reminding me about the charts. I'll look into possibly re-gearing to 4.56 for this set up.

Now that you dropped a couple thousand on your axles, hows your trans? I'm assuming your running an automatic. If its in good shape put a nice big trans cooler on and service it. How old is your cooling system? Make sure that's in good shape too. The trans and eng cooling systems are where I've watched most people have issues. If you do the axles correctly, with good parts, you wont break anything. The only mod's my Cherokee had was a nice trans cooler, trans temp gauge and better radiator. With the 4.10's and 32's it did bog a bit on hills. If I kept it i would have re geared it.

My Jeep is a manual. Overall it's in good shape. New clutch was put in not too long ago. I'm planning on doing a full tune up on the Jeep before the trip also. Change all fluids, plugs, wires, filters, etc.

 

[Anak]

For a manual 4.10s and 33"s are probably a reasonable choice.

 

[HoneyBadgerXJ]

For a manual 4.10s and 33"s are probably a reasonable choice.

The gearing is definitely pretty high as it is with 31s. That's why I was thinking that the same ratio would be fine with 33s.

 

[HoneyBadgerXJ]

So, just to re-ask a question from earlier, if I upgrade my axle shafts to 29 and 30 spline, I'm assuming I'll need to change the spider gears to match right? I feel like that's a silly question, but I've been looking around and I can't find any spider gears in the higher splines for my axles. Not sure if I'm over thinking this or not.

 

[Smileyshaun]

honestly I think your getting way ahead of yourself if your mostly back road/forest service road and light to moderate trail running I wouldn't worry about your axles at all , change fluids , put breaks and some quality ball joints carry a couple spare u joints and put money into making the trip more enjoyable .
also 33x10.50s on some aluminum rims fit wonderfully under a xj and will help to cut down on drivetrain stress and will lessen the mpg drop .

 

[HoneyBadgerXJ]

honestly I think your getting way ahead of yourself if your mostly back road/forest service road and light to moderate trail running I wouldn't worry about your axles at all , change fluids , put breaks and some quality ball joints carry a couple spare u joints and put money into making the trip more enjoyable .
also 33x10.50s on some aluminum rims fit wonderfully under a xj and will help to cut down on drivetrain stress and will lessen the mpg drop .

That’s definitely something I’ve been keeping in mind. I don’t want to go overboard on my build. The only thing though is I do intend to hopefully encounter some more intense and technical terrain in the future. If not on this trip then another one. And We don’t have any routes planned yet. It’s still pretty early. I’m already planning on putting lockers in, so I figure why not do it all at once. This is also all part of my R&D phase of my build so to speak. There’s a lot of high aspirations and cutting back to be reasonable in certain areas. You should have seen my dream list when I first got started lol.