Axle Swap Advice

[Anak]

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.

The spider gears you are looking for will come as part of the new carriers that will be required to go along with the larger axle shafts.

If you just want to install lunch box lockers (and thus avoid redoing the gear sets) then don't bother trying to change your axles. Just run the spline counts you already have.

If you are planning to install lockers that are full carriers (and will require redoing your gear sets) then it is worth considering ordering new, larger axles to go along with the new carriers. The price for the carriers is generally the same, regardless of spline count. Resetting the gears is the same, regardless of spline count. It is just a matter of adding the cost of new axles to all the rest of the package.

Only you can weigh the pros and cons of the options and decide what makes the most sense for your scenario.

 

[HoneyBadgerXJ]

The spider gears you are looking for will come as part of the new carriers that will be required to go along with the larger axle shafts.

If you just want to install lunch box lockers (and thus avoid redoing the gear sets) then don't bother trying to change your axles. Just run the spline counts you already have.

If you are planning to install lockers that are full carriers (and will require redoing your gear sets) then it is worth considering ordering new, larger axles to go along with the new carriers. The price for the carriers is generally the same, regardless of spline count. Resetting the gears is the same, regardless of spline count. It is just a matter of adding the cost of new axles to all the rest of the package.

Only you can weigh the pros and cons of the options and decide what makes the most sense for your scenario.

Okay great, that’s what I was hoping. Thanks for all the help Anak

 

[4wheelspulling]

HoneyBadgerXJ,
For the whole part, the information is correct so far. 96’ XJ without ABS will have the 27 spline, 8-1/4” Rear, and the Dana 30, 30 spline reverse rotation front end. Now if you have the ABS, you have the Dana 35 Rear. Still the same 30 front. Fire roads and Auto trans., the 27 spline 8-1/4 will be just okay, on 33”. A little iffy with a locker! With ABS, 31s” and no locker! If your gears or stock, you have 3.54 with Auto trans. Tow package, maybe 3.73. Your 96’ does have the larger 760x front u-joints.
So, biggest factor would be any problems you know about have them fixed before you go! Make sure to have a good lube job done and have everything checked out and ready. I would stay with 31s” but that is just me. Lots for people run stock everything, trim fender and run 33s” with out much problem. Benz.

 

[HoneyBadgerXJ]

HoneyBadgerXJ,
For the whole part, the information is correct so far. 96’ XJ without ABS will have the 27 spline, 8-1/4” Rear, and the Dana 30, 30 spline reverse rotation front end. Now if you have the ABS, you have the Dana 35 Rear. Still the same 30 front. Fire roads and Auto trans., the 27 spline 8-1/4 will be just okay, on 33”. A little iffy with a locker! With ABS, 31s” and no locker! If your gears or stock, you have 3.54 with Auto trans. Tow package, maybe 3.73. Your 96’ does have the larger 760x front u-joints.
So, biggest factor would be any problems you know about have them fixed before you go! Make sure to have a good lube job done and have everything checked out and ready. I would stay with 31s” but that is just me. Lots for people run stock everything, trim fender and run 33s” with out much problem. Benz.

Thanks for the info. My XJ is the non-ABS model. I know for sure that I have the c8.25 rear and the high pinion d30 front. As far as splines, I wasn’t sure, due to the spline count being changed up halfway through the production year. It’s also a 5 speed with the AX15 tranny and is currently geared to 4.10. As far as terrain, I still don’t know what exactly to expect. Definitely going to be some fire roads and probably some more technical trails. The trip is still in it’s early planning stages since it’s not until next year.

 

[4wheelspulling]

Thanks for the info. My XJ is the non-ABS model. I know for sure that I have the c8.25 rear and the high pinion d30 front. As far as splines, I wasn’t sure, due to the spline count being changed up halfway through the production year. It’s also a 5 speed with the AX15 tranny and is currently geared to 4.10. As far as terrain, I still don’t know what exactly to expect. Definitely going to be some fire roads and probably some more technical trails. The trip is still in it’s early planning stages since it’s not until next year.

HoneyBadgerXJ,
Our Cherokees are much the same as I have a 95’ with manual transmission. With the terrain of Alaska, I would stick with the 31” tires, but that is just me. With a load of camping gear and some of the hills you will have more power. To bad you do not have the factory limited slip, then you would be good to go. Might be time to look for a 97’-01’ Rear 8.25 (29) spline, and it would just be a bolt in, if you can find one with 4.10s. Then put the money into a nice locker! Benz.

 

[HoneyBadgerXJ]

HoneyBadgerXJ,
Our Cherokees are much the same as I have a 95’ with manual transmission. With the terrain of Alaska, I would stick with the 31” tires, but that is just me. With a load of camping gear and some of the hills you will have more power. To bad you do not have the factory limited slip, then you would be good to go. Might be time to look for a 97’-01’ Rear 8.25 (29) spline, and it would just be a bolt in, if you can find one with 4.10s. Then put the money into a nice locker! Benz.

There is a company I found that makes electric lockers that also convert your diff to an lsd when the they aren’t engaged. Sadly I can’t remember the name of them though.

 

[JDGreens]

Have you already had your gears swapped to 4.10's? Mine came with 3.07 gears and was a dog with 33" tires. I swapped in axles with 3.55 gears a little better. (Also danna 35 for a chrysler 8.25)
A lot of great advice with all the input here in the thread you have going!

But if you do have 4.10's I wouldn't worry a bit. I wouldn't change Splines count or change your rear axle either. The Danna 30 is your weak link but with 33"s very adiquite as long as you take things with a bit of caution. The reason I wouldn't change the spline count is because you can carry spares. (Which fit nicley under your rear seat). Or someone might have a spare that would work in a pinch. Your spares might save someone else some griff as well. But won't help if you have 30 spline. The weak link is near the u-Joint not the shaft it's self. Ask me how I know! (I wasn't being cautious at all and should not have been trying to tackle what they call little Moab with my set-up on the hardest line). Which is a good thing as if it breaks there no big deal. A littke elbow grease and you are back in business.
Honestly if you are going to 35"s my advice would change but then so much more would need to be done than just beefing up your axles.

If you don't have a winch I would put my money there .

I would do your trip and evaluate things afterwards. You will be surprised with how well your set-up will do overlanding.

 

[HoneyBadgerXJ]

Have you already had your gears swapped to 4.10's? Mine came with 3.07 gears and was a dog with 33" tires. I swapped in axles with 3.55 gears a little better. (Also danna 35 for a chrysler 8.25)
A lot of great advice with all the input here in the thread you have going!

But if you do have 4.10's I wouldn't worry a bit. I wouldn't change Splines count or change your rear axle either. The Danna 30 is your weak link but with 33"s very adiquite as long as you take things with a bit of caution. The reason I wouldn't change the spline count is because you can carry spares. (Which fit nicley under your rear seat). Or someone might have a spare that would work in a pinch. Your spares might save someone else some griff as well. But won't help if you have 30 spline. The weak link is near the u-Joint not the shaft it's self. Ask me how I know! (I wasn't being cautious at all and should not have been trying to tackle what they call little Moab with my set-up on the hardest line). Which is a good thing as if it breaks there no big deal. A littke elbow grease and you are back in business.
Honestly if you are going to 35"s my advice would change but then so much more would need to be done than just beefing up your axles.

If you don't have a winch I would put my money there .

I would do your trip and evaluate things afterwards. You will be surprised with how well your set-up will do overlanding.

Thanks for the input JD. I think what I've decided on is to definitely swap the axle shafts for the higher spline count. I want that extra strength and I want to do all the work on my axles in one go rather than keep coming back to them to do more. Right now it's geared to 4.10. When I bought it, it was already sitting on 31s with the stock 3.73 (I think that's what it was) and it was terrible. It had no power and would bog down hard on hills. 33" is as big as I'm planning on going for my tires for now. Also I like how steep the gear ratio is with the 4.10/31" combo, so I'm considering 4.56 for the 33s, but I'm not sure yet. Plus it'll help with power with all the added weight of bumpers, camping gear, etc. It'll probably be a bit obnoxious for an overland build, but we'll see. It'll also be a good gear ratio to have if/when I decide to up my tires to 35". My list of parts for the build is ever changing, but a winch is certainly a constant.

 

[Smileyshaun]

If it's bogging on hills with 3.73s and 31s i would look into making sure all your mechanicals are in good working order , full time up , make sure your timing is right , compression is good , o2 sensors are working correct, don't have excessive blow by built up in the valve cover ( only certain years had this issue ) . the 4.0 is a good hill pulling motor 31s shouldn't effect it that much

 

[JDGreens]

Thanks for the input JD. I think what I've decided on is to definitely swap the axle shafts for the higher spline count. I want that extra strength and I want to do all the work on my axles in one go rather than keep coming back to them to do more. Right now it's geared to 4.10. When I bought it, it was already sitting on 31s with the stock 3.73 (I think that's what it was) and it was terrible. It had no power and would bog down hard on hills. 33" is as big as I'm planning on going for my tires for now. Also I like how steep the gear ratio is with the 4.10/31" combo, so I'm considering 4.56 for the 33s, but I'm not sure yet. Plus it'll help with power with all the added weight of bumpers, camping gear, etc. It'll probably be a bit obnoxious for an overland build, but we'll see. It'll also be a good gear ratio to have if/when I decide to up my tires to 35". My list of parts for the build is ever changing, but a winch is certainly a constant.

Yeah with the regearing to 4.56 grears and 33" tires, although might be a little to steep I would rather have more torque (power) to climb the mountain paases when pulling my trailer than being able to keep up with traffic at 70 mph. I bought some axles from a guy that was into rock crawling and was swapping in full sized axles. These axles (danna 30 and danna 44) are loaded with arb lockers and 4.55 gears. I would already have them installed but I need to have the guts in the danna 30 swapped into my axle. (Something I'm not confident doing). The axle is a pre- 1991 axle with the actuator to ingadge the 4wheel drive. So I am going to have a shop do that work. I should have them installed for next season for sure.

If you get 4.56 gears in with the 33"s could you update how you feel about the combo? Anyways good luck with your adventure. I think your xj will do fine!

 

[jeepnjeff]

Since you have an XJ, have you thought about locating a '87-89 Dana 44 from an XJ/MJ? They are a true Dana 44 with the thicker axle tubes BUT use the same axle shafts that the Rubicon's used later on. It would be bolt-in for you. Stock gears are 3.54's or 3.07's. Brakes are 10"x2.5" drums which are an inch latger in dia. then your 8-1/4". The BOM numbers are:

605325-12 MJ 3.07
605325-10 MJ 3.54
605342-1 XJ 3.07
605342-3 XJ 3.54
​

I run an XJ Dana 44 in my YJ. I've upgraded mine with 4.56 gear and a Detroit Locker. I've run 32x11.5R15's, 35x12.5R15's and now 33x10.5R15's.

If you're able to do some welding then a Ford 8.8 from a Ford Explorer or a 9" from a Crown Vic/Grand Marquis, etc... There's also the Isuzu Trooper Dana 44...

 

[JDGreens]

My Danna 44 is out of a scout, since it is already set-up w/the gears and arb locker I just have cut the shock mount and leaf spring mounts and set it up under my xj and weld new ones on. Re-plumb brake lines. The one thing I want to get done first is my SYE. So I get the angles correct the first time rather than using wedges later to coorect the pinion angle.
JEEP (just empty every pocket) Right!

 

[HoneyBadgerXJ]

If it's bogging on hills with 3.73s and 31s i would look into making sure all your mechanicals are in good working order , full time up , make sure your timing is right , compression is good , o2 sensors are working correct, don't have excessive blow by built up in the valve cover ( only certain years had this issue ) . the 4.0 is a good hill pulling motor 31s shouldn't effect it that much

To be completely honest, I think it was less then 3.73. I think it was more like 3.54 or something. But mechanically, the Jeep is great. And once I re-geared, it was much better.

 

[HoneyBadgerXJ]

Yeah with the regearing to 4.56 grears and 33" tires, although might be a little to steep I would rather have more torque (power) to climb the mountain paases when pulling my trailer than being able to keep up with traffic at 70 mph. I bought some axles from a guy that was into rock crawling and was swapping in full sized axles. These axles (danna 30 and danna 44) are loaded with arb lockers and 4.55 gears. I would already have them installed but I need to have the guts in the danna 30 swapped into my axle. (Something I'm not confident doing). The axle is a pre- 1991 axle with the actuator to ingadge the 4wheel drive. So I am going to have a shop do that work. I should have them installed for next season for sure.

If you get 4.56 gears in with the 33"s could you update how you feel about the combo? Anyways good luck with your adventure. I think your xj will do fine!

That should be a good set up. I originally wanted to do d44s but opted not to for the sake of money and time. I don’t blame you for wanting a shop to do it. I wouldn’t do it myself either. Not uless I had the time and could afford to make a mistake and learn. Also, yeah, I’ll gladly post an update if I get the 4.56s with 33’s. I’m planning on getting started in October so it’ll probably be around that time frame. After the Alaska trip next year I think I’ll do a build thread also that will include a review of how everything performed on the trip.

 

[HoneyBadgerXJ]

Since you have an XJ, have you thought about locating a '87-89 Dana 44 from an XJ/MJ? They are a true Dana 44 with the thicker axle tubes BUT use the same axle shafts that the Rubicon's used later on. It would be bolt-in for you. Stock gears are 3.54's or 3.07's. Brakes are 10"x2.5" drums which are an inch latger in dia. then your 8-1/4". The BOM numbers are:

605325-12 MJ 3.07
605325-10 MJ 3.54
605342-1 XJ 3.07
605342-3 XJ 3.54
​

I run an XJ Dana 44 in my YJ. I've upgraded mine with 4.56 gear and a Detroit Locker. I've run 32x11.5R15's, 35x12.5R15's and now 33x10.5R15's.

If you're able to do some welding then a Ford 8.8 from a Ford Explorer or a 9" from a Crown Vic/Grand Marquis, etc... There's also the Isuzu Trooper Dana 44...

I considered looking for a good axle to swap in, but the only obstacle is that I live outside the us. I’m contracting overseas and flying back to the States to work on my Jeep. So I’m not really sure how easy it would be to find something and arrange a buy/pickup. It’s definitely an option I’ll consider when I move back, but for now I think building the axles I have will be more practical for my situation.

 

[JDGreens]

Yeah 3.54 is what I have, taking ales from a Xj with an automatic tranny it is a very economical way to upgrade the axles and gearing in a Xj with the ax-15. I struggle with crawling over the large obstacles . It will be nice to have the lower gearing so that takes less effort to crawl along. I wonder if 4.10s would be the perfect gearing for my rig, but these axles are already set, and will save me a lot of money if they turn out to be solid. So 4.55 gears will have to do.
I wonder if anyone could chime in on what rmps they are at when driving 65 and 75 mph. With 4.56 gears and 4.10 gears.
I am very curious what to expect and might help with your decision for your gearing. I figure being able to tow a trailer up mountain passes without straining the engine is more important than keeping up with traffic. Although I took a trailer up camping the last trip and my rig did ok with the 3.55 gears and the 33"s. But wheeling I defiantly could use the steeper gearing. It will help me not to have to over rev when trying to gingerly climb over the terrain. It will almost idle through things instead.

 

[Overland California]

@JDGreens you could definitely used some lower gears – and a locker. 4.10s would be ideal for 33's. You might lose a little mpg on the highway but you'll get all your low end grunt back.

 

[old_man]

More important than upgrading the rear axle assy is upgrading the D30 up front. I don't mean replacing it, but at least upgrading the axle shaft on the drivers side. That is the one that breaks the most. I have rock crawled the heck out of my rig for 23 years. I am running Dana 44's locked front and rear on 35's. I live in Colorado and wheel all over as well as all the hard trails in Moab. Experience and judgement will get you there when testosterone won't.

 

[4wheelspulling]

There is a company I found that makes electric lockers that also convert your diff to an lsd when the they aren’t engaged. Sadly I can’t remember the name of them though.

You are thinking of Auburn! Benz.

 

[4wheelspulling]

HoneyBadgerXJ,
Maybe this would be a good way to go and save some money? Have you looked at the replacement axles from, Ten Factory Rear axle kits? Quadratec has a kit with new bearings and chromoly axles for 27 spline, 8-1/4 for $265. Just thought I would pass that on. Might be a good cheap way to upgrade, and do what you need. Benz.