JK to TJ Rear Axle Swap: Slow Build

[BuildBreakRepeat]

Pretty interesting. Do they still fit in the same case? Or does the JK have a special cover?

I believe the covers are interchangeable, although one company noted that different years will have different lips overhanging the case, as if to imply the bolt pattern and arrangement is similar but not thickness or sizing wise. Here’s some more info I found!

“The carrier bearings are slightly larger in diameter with the new generation Dana 44 found in Rubicon models. Another difference is found in the design of the differential. The cross-pin in the Rubicon next-gen 44 is not in the same place as the first gen, requiring different length axleshafts. The Rubicon model next-gen 44 front axleshafts also used larger steering joints and had more beef around the joints. The non-Rubicon JKs only came with a Dana 44 rear axle. The differential and carrier bearings in the non-Rubicon models are the same as the older generation 44s.”

 

[Mike_H]

Pretty interesting. Do they still fit in the same case? Or does the JK have a special cover?

Same cover...I bought a spare set of factory covers to add armor to the lower half...Basically, I want to copy the Barnett Design. I paid 50 bucks for both covers, shipped, and I get to play with my welder, so I thought it was a good deal.

 

[ac_]

I believe the covers are interchangeable, although one company noted that different years will have different lips overhanging the case, as if to imply the bolt pattern and arrangement is similar but not thickness or sizing wise. Here’s some more info I found!

“The carrier bearings are slightly larger in diameter with the new generation Dana 44 found in Rubicon models. Another difference is found in the design of the differential. The cross-pin in the Rubicon next-gen 44 is not in the same place as the first gen, requiring different length axleshafts. The Rubicon model next-gen 44 front axleshafts also used larger steering joints and had more beef around the joints. The non-Rubicon JKs only came with a Dana 44 rear axle. The differential and carrier bearings in the non-Rubicon models are the same as the older generation 44s.”

Since I am not in the field anymore that is good information. It sounds like they designed these specifically for JK Rubicons.

 

[S.McArthur]

Update: We are having a week long welding course at work starting 29Apr, I will be using my axle as a "project" for the week.
I cannot find a simpler solution to welding brackets, so the Artec truss is on order.

I've priced out every little thing I'll need to build this axle and it is going to be over my $3k "budget" if I go with all new parts. The issue is that I bought a completely bare axle without any axle shafts/brakes/backing plates/lines/etc. Those items are going to nickel & dime me unless I can find some parts in jeep clubs/craigslist/etc. Had I bough an axle with the stock shafts/brakes, the cost would be a whole lot less just to get the axle under the jeep.
The only really big purchase is the locker and installation labor, I am not even going to attempt to install the locker myself.

So, my apologies for the lack of progress, as I mentioned in my first post, I am in no rush to complete this project. If I was not in the middle of home repairs/getting ready to sell, I'd have extra time/expendable income. Have patience, this is going to happen and I'll document it as best I can.

 

[mrblaine]

Yes and no. The JK axle is claimed to be a "almost a dana 60" and can take a beating especially under the lighter (not much) TJ. I'm not jumping it, but I will be exploring the capabilities of the Jeep. If peopel in Johnson Valley are beating the snpot out of Super 35's, I should have no issue with the larger/stronger JK Dana 44.

You have to put that in context. The guys running the Super 35 are not idiots and are on 35's. No one swapping in a JK usually stays on 35's, they are trying to circumvent getting a real axle to handle larger than 35" tires.

The ones who have swapping in the JK front and rear 44's for 37's would not do it again and instead would get real axles.

 

[S.McArthur]

not idiots

This is a large contributing factor in most cases.

get real axles

Agreed, if I planned on going that route, I'd pay the Currie price or find something "kewl". For what I need, these JK axles will be more than enough. I have no intention of going over 35's/stretching/cutting body/etc.

I'll leave it at that as I would be talking out of my ass theorizing why JK axles are breaking. I will be calling you to ask some stupid questions however. I'm not at that point yet, no use getting info I'll forget.

 

[mrblaine]

I'll leave it at that as I would be talking out of my ass theorizing why JK axles are breaking. I will be calling you to ask some stupid questions however. I'm not at that point yet, no use getting info I'll forget.

The ones we are around and take care of aren't breaking. They just require lots of maintenance and new parts to keep going. Balljoints, rear axle shafts, stock locker, and front shafts until you get to the RCVs and then they start clicking fairly quickly which isn't covered by warranty.

 

[S.McArthur]

lots of maintenance

Are those rigs running 37"+ tires? Or built to run JV/west coast type terrain?
My shit box will not go over 35" rubber and that is way down the road, my "skill" level/terrain do not warrant that type of build and I still need this jeep to be a 80/20 DD/off-road machine & deer cart (is that 80/10/10? or 80/15/5?).
I feel like I have a good plan in place, you are giving me some second thoughts, not bad, just over thinking type thoughts. I do not see much issue with 33" wheel/30 spline rear Dana 44 w/locker. I do pretty well on open Dana 35, 32" & lunchbox locker in the Dana 30 if that is an indication of the "hardcoreness".
As for the front axle, there is a good chance I'm going to buy a bolt in axle; from whom? Not sure yet.

 

[mrblaine]

Are those rigs running 37"+ tires? Or built to run JV/west coast type terrain?

37's only. Yes, JV, Moab, Rubicon, Parker, Sand Hollow, etc.

My shit box will not go over 35" rubber and that is way down the road, my "skill" level/terrain do not warrant that type of build and I still need this jeep to be a 80/20 DD/off-road machine & deer cart (is that 80/10/10? or 80/15/5?).
I feel like I have a good plan in place, you are giving me some second thoughts, not bad, just over thinking type thoughts. I do not see much issue with 33" wheel/30 spline rear Dana 44 w/locker. I do pretty well on open Dana 35, 32" & lunchbox locker in the Dana 30 if that is an indication of the "hardcoreness".
As for the front axle, there is a good chance I'm going to buy a bolt in axle; from whom? Not sure yet.

You don't see much issue with 33's and the work it takes to swap in that axle. I don't see any issue with 33's, 35's and a Super 35 kit with a selectable locker for the same set up and what you describe. Just perspective.

Put another way, if you brought me the JK rear 44 and the rig, I wouldn't install it for 35's and down unless there were some very extenuating circumstances.

 

[S.McArthur]

Just perspective

Gotcha,

 

[S.McArthur]

Artec Truss has arrived, quick inventory and mock up to get a feel for the process. It is missing the tubes for the coil springs; a quick call to Artec and they already have sent the pieces out to me.
I need to find some junk control arms bushings/joints to use during the welding phase. Everything fits together quite well, just need to make sure the distance for the driver side upper control arm mount is just right. Overall, it appears to be a straight forward process; Murphy's law will most likely negate that theory.
As mentioned before, installing the truss will begin on the 29th and should conclude NLT 2/3May.

 

[S.McArthur]

Change #1: Traded Sahara axle for a Rubicon Axle. Axle is complete rotor to rotor with the stock e-locker, quite sure I just saved myself about $2k for this swap.
Monday is go time, as of now, I need to strip this one and clean it up for next week.

 

[Mike_H]

Change #1: Traded Sahara axle for a Rubicon Axle. Axle is complete rotor to rotor with the stock e-locker, quite sure I just saved myself about $2k for this swap.
Monday is go time, as of now, I need to strip this one and clean it up for next week.
View attachment 90049
View attachment 90050

WoW! Nice Trade! How did you swing that? Someone must really have wanted those 3.73 gears!

 

[S.McArthur]

WoW! Nice Trade! How did you swing that? Someone must really have wanted those 3.73 gears!

LOL, I had to toss some cash at it. Not a straight up swap, I should have worded that better. Either way, I'm into the axle at $800 and now have a locker, so scratch $1k off the Eaton E-Locker I was planning on buying.
Having some issues pulling the shafts, I think they've been sitting a while and I need to get my good pry bar. I just tested the locker and it engages with 12v no problem.
The rotors are most likely at the rust point where I'll replace them and the pads. Other than that, the axle looks to be in great shape.
I probably could have found a TJ Dana 44 for the cost, but I'm looking forward to the "stronger" JK rubicon axle.

 

[S.McArthur]

Well, got all the crap off the axle, forgot how terrible gear oil smells. The oil was thin and really looked like crap, but it also has been sitting stagnant for a while. I had to loosen the carrier bearing caps to release the axle shafts, believe me, I tried every pry bar/hammer combo I had on hand before that point. I'll get the carrier out in due time, it needs a good cleaning as well.

I want to reuse the axle shafts, but the bearing don't look to healthy, plus I can order some RG&A that allows me to switch between TJ/JK bolt patterns.

Brake rotors are most likely junk, no reason to resurface them. Backing plates/E-brake stuff could probably be cleaned and reused; pads are probably going to be replaced. I'll cross that path when I get there or Mr.Blaine chimes in with his wisdom.

Going to start to look at new seals etc, no use putting garbage back into the axle. I'm going to pressure wash it and it will be ready for cutting on Monday.

 

[S.McArthur]

Today is the day, off with the old, on with the new. Received a present from the brown truck yesterday.

 

[mrblaine]

Well, got all the crap off the axle, forgot how terrible gear oil smells. The oil was thin and really looked like crap, but it also has been sitting stagnant for a while. I had to loosen the carrier bearing caps to release the axle shafts, believe me, I tried every pry bar/hammer combo I had on hand before that point. I'll get the carrier out in due time, it needs a good cleaning as well.
View attachment 90197
I want to reuse the axle shafts, but the bearing don't look to healthy, plus I can order some RG&A that allows me to switch between TJ/JK bolt patterns.
View attachment 90195
View attachment 90196
Brake rotors are most likely junk, no reason to resurface them. Backing plates/E-brake stuff could probably be cleaned and reused; pads are probably going to be replaced. I'll cross that path when I get there or Mr.Blaine chimes in with his wisdom.
View attachment 90198

Going to start to look at new seals etc, no use putting garbage back into the axle. I'm going to pressure wash it and it will be ready for cutting on Monday.

I would find a way to make sure that the housing is straight. If you had to loosen the carrier to get the shafts out, that is usually the first indicator that the housing is bent, and bent enough to see easily.

 

[S.McArthur]

I would find a way to make sure that the housing is straight.

I just finished cutting off the JK mounts and put a straight edge on it, it appears to be fine. I think I just didn't use a big enough pry bar to remove the shafts, the only pry bar I had was a 12" one. Once I have the tubes cleaned up I'll check again.
How do you feel about those backing plates?

 

[mrblaine]

I just finished cutting off the JK mounts and put a straight edge on it, it appears to be fine. I think I just didn't use a big enough pry bar to remove the shafts, the only pry bar I had was a 12" one. Once I have the tubes cleaned up I'll check again.
How do you feel about those backing plates?

They's fine.

 

[S.McArthur]

Sneak peak to prove it’s going down...