JK front Dana 44 swap into LJ

[LJTim]

I thought I would post this project on here for a few reasons. I have never done anything like this (aside from swapping a HP30 in place of my stock LP30), but it is time to step up the girth of my front end. First off, I understand my build is controversial to a lot of people that will just say, "get Tera 60's or Super Duty Axles," but I'm not interested in that. The JK44 will give me what I'm looking for in weight, clearance, width, bolt pattern and additional strength. I have already been pushing 37's with my locked HP30 for several years with great success. I don't rally or jump my jeep, and I'm typically gentle with the throttle. I do use it though, and am regularly running 7/8-rated trails at Sand Hollow and Moab. I will stick with my 37's for a while, but may step up to 40's in the next couple years. I believe a cryo treated JK44 ring and pinion will do easily just as well with 40's as my current HP30 is doing with 37's. Another difference worth noting is I'm currently using 4.88 gears, and will likely change to 5.38's at the time of the swap. I have already picked up a gently used housing for my project, but I need to pick up a few things to get this ready. It is a long term project, so if there are items you suggest that I should just pick up as used OEM items that people have swapped out, I'm definitely game for that. Something to keep in mind is I have a very tight budget, so if money can/should be saved in some areas, which areas should those be? Please note I'm no master welder, but I can get some things done with my piece of crap Harbor Freight welder, and would like to do as much of the work on my own as possible (again, I'm cheap). I do plan to reach out for a few items for welding that I think are too much for me, or I'm concerned about the looks of the welds. For those wondering how I'll keep the axles squared, and matching wheels, I already use 2.5" wheel adapters to a JK pattern, so I have 17" JK wheels. The extra 5" in the rear with the spacers should almost perfectly match the WMS width of the new JK44. Items I would love input on are numbered below. Thanks in advance. And thanks for reading this super long post!

1. To truss or Not to truss: One option is to get the Artec JK2TJ axle swap kit. This includes a truss, but does not include a cradle over the diff. It does, however include the lower spring perches that relocate them to TJ/LJ spec. It also includes inner C gussets, sway bar link perches and lower control arm mounts. But, the kit is expensive. I'm curious if I could be happier with just sleeving the tubes, adding inner C gussets, lower spring buckets, LCA mounts and Swaybar mounts. I have also looked at TNT's truss which is designed to do the same thing as Artec - grind off all the mounts, weld in this truss, and it becomes a direct bolt-on axle. This kit is much cheaper than Artec's as well.

2. Knuckles: I am currently using Currie's Currectlync steering, which is basically beefed up stock inverted Y steering. I have been happy with this, and I have never bashed my tie rod, but I'm not sure how the location of the JK steering relates to my current set up. If I use stock knuckles, will I wish I would have upgraded to Rancho or Reid knuckles to get a high-steer set up? Are there any other reasons I should look at the aftermarket knuckles I've mentioned?

3. Steering: I planned on using either a Ruffstuff 1 ton tie rod, or just fabbing a complete steering set up since my drag link will need to be a different length than a stock JK drag link. I believe a custom track bar will need to be made as well, but since I'm not really a fab guy, if there is something that already exists, I'd love it but I don't really want to spend $1000 for Currie's Modular Extreme steering, although I love the looks of it.

4. Brakes: I hear a lot about the big brake conversions available for JK's. Is this necessary? I know stopping 37's or 40's takes some effort, but also remember, I don't weigh as much as a JK. I weigh about 4700. Would it be worth just using some stock take-off calipers from a JK, and just upgrade pads and rotors? Also, please correct me if I'm wrong, but I believe I can stick with my stock steering box and pitman arm? I do plan to add a redneck ram assisted box that uses a stock TJ box that comes drilled and tapped, ready to bolt in (and weld the ram bracket to the tie rod). Is there anything else I need to do to get the brake lines to work with the JK bolts? Can I use my extended braided TJ lines with some minimal modification?

5. Shafts: I am currently using RCV shafts with my HP30, and have been very happy with them. The reason for using them on my "budget" build is I kept wearing out u-joints, and I wouldn't notice they were bad until they started rattling. by then, I had already worn out my ears on the outer stub shafts making repairs more expensive than they should have been. I have also heard great things about the G2 Gold axle shafts because they have beefed up the ears around the u-joints a ton. They are still $1000 though, so maybe I might as well get RCV's if I spend that much. However, maybe I should keep the axle joints as my weaker point, if something is to break? I'm open to discuss this.

6. Suspension links: Although due to budget constraints, I will likely save this for 1-2 years down the road after the swap is complete - I still would like to discuss link suggestions, keeping in mind this is meant to be a capable rig, but I love driving it around town, and use it 4 days of the week driving 75 on the highway regularly. I currently have short arms with Johnny Joints on all ends, and it performs well, but i eventually want to 4-link the rear and get rid of my rear track bar, and stretch the rear back a few inches. For the front I'm prone to favor a 4-link just for the simplicity of using the stock upper axle mounts, and should work well on and off road. BUT almost every complete kit available utilizes a 3-link design. Of all the complete kits available, I favor the Savvy mid-arm for its proven track record, simplicity and that I won't have to replace or modify my current skid set up, where most of the others ties into a skid/crossmember fr their frame mounts.

7. Misc brackets and other: Correct me if I'm wrong, but I assume I will need a new upper track bar bracket? If there are other items I have not considered, please bring it to my attention. I am no expert, but I'm pretty handy, so I'd love to discuss anything other than NOT doing the project

 

[Greg]

I don't have all the answers to your questions, but I will weigh in. I was surprised at how weak my JK Dana 44 was, once I had a failure and really started digging into it. Everything about the housing is under-built. What really caught me off guard was how all the link brackets, including the track bar, are very thin stamped steel. Fine for stock sized tires and mild offroading, IMO but that's about it. I would highly suggest that in your plan, you replace all the suspension link tabs and the track bar bracket with aftermarket mounts on the axle. I'd think a truss, Artec or TNT, would be wise.

I believe the factory JK outer knuckles are decent far as strength, but high-steer sure would be nice to add while you're building... but it's not cheap. I bet you could flip the tie rod to gain a little more clearance, as the least. For sure gusset the inner knuckles.

I don't think bigger brakes are needed for your LJ with a JK axle... I think you could get away with stock rotors and high quality brake pads. I'm running that setup and don't find my piggy JKU hard to stop. I'd love to upgrade to larger rotors at some point, but I'd bet my JKU weighs considerably more than your LJ.

I'd go for the RCV's in the JK axle and not plan on building a 'fuse' onto the front shafts. I upgraded to Spicer front shafts with 1350 joints and while they haven't failed, I would have loved RCV's. For me, it came down to sticking with 35's and cost. If I were running any bigger tire, I'd have gone to RCV's.

IMO, it would be wise to beef up the upper track bar bracket considering the 40" tires. I don't think it's a common breakage point, but 40's do a good job of finding weakness!

Oh, I would suggest getting rid of the factory JK ball joints. TeraFlex makes a very heavy-duty set of ball joints and they're even adjustable if by chance they develop play in them over time. Mine have been in place for a couple years now and I haven't needed to touch them.

I know @anderson750 did swap JK axles into his TJ years ago, but he's getting up there in years and probably forgot all the details by now.

 

[Mouse]

For the track bar, you'll want it to match the draglink in angle and length as much as possible. Depending on how the angle and length works out will determine the optimum frame location for a bracket. The axle side has the same concerns. You also need to decide what kind of joints you want to use. I've had success using 3/4" heims, but bigger (like 7/8) will be more durable. Poly-jointed type ends are probably a better choice for a daily driver rig as heims don't usually have an option for lubing them (like a grease fitting) and can become noisy as they wear out.

 

[pkrfctr]

I have 2 friends that have done this. It's a decent axle. Both friends said it would have been waaay cheaper to put an aftermarket axle in. The 'little' things eat you alive. They both did front and rear swap and were both into it over $11k. You don't need the rear but most the cost is the front. BDS just had Corbin do axles and after looking at cost vs. Reward to build his jk front, he ended up with an aftermarket 44.
Steering 40's on stock steering will suck! All the guys I wheel with go to assist at 37's. Hell my psc has a hard time from time to time if my rpm's are low.

 

[Greg]

I have 2 friends that have done this. It's a decent axle. Both friends said it would have been waaay cheaper to put an aftermarket axle in. The 'little' things eat you alive.....

That's interesting.... good to know, for someone considering this. On my JKU, I decided the most logical thing was to upgrade to a Tera 44 housing, was able to re-use my locker, gears, brakes, axle shafts, etc. The price for the housing was $2300, which I decided was worth paying rather than dealing with adding sleeves, replacing all the link brackets, welding gussets to the knuckles, etc.

https://teraflex.com/shop_items/jk-front-0-3-tera44-replacement-axle-housing-tf44

I wonder if you can buy a bare Tera44 housing without the coil buckets, making a JK to TJ/LJ swap easier?

 

[LJTim]

I have considered a Tera 44. Even though they aren’t on their site Corbin has said it’s easy to build it for a TJ instead of a JK (the coil buckets that is). I’m pretty set on doing this, as I can’t possibly see how a complete after market axle would save me any $, but I’ll run some #s before I purchase anything for the housing. Thanks for the thoughts thus far.

 

[RockChucker]

See responses below.

I thought I would post this project on here for a few reasons. I have never done anything like this (aside from swapping a HP30 in place of my stock LP30), but it is time to step up the girth of my front end. First off, I understand my build is controversial to a lot of people that will just say, "get Tera 60's or Super Duty Axles," but I'm not interested in that. The JK44 will give me what I'm looking for in weight, clearance, width, bolt pattern and additional strength. I have already been pushing 37's with my locked HP30 for several years with great success. I don't rally or jump my jeep, and I'm typically gentle with the throttle. I do use it though, and am regularly running 7/8-rated trails at Sand Hollow and Moab. I will stick with my 37's for a while, but may step up to 40's in the next couple years. I believe a cryo treated JK44 ring and pinion will do easily just as well with 40's as my current HP30 is doing with 37's. Another difference worth noting is I'm currently using 4.88 gears, and will likely change to 5.38's at the time of the swap. I have already picked up a gently used housing for my project, but I need to pick up a few things to get this ready. It is a long term project, so if there are items you suggest that I should just pick up as used OEM items that people have swapped out, I'm definitely game for that. Something to keep in mind is I have a very tight budget, so if money can/should be saved in some areas, which areas should those be? Please note I'm no master welder, but I can get some things done with my piece of crap Harbor Freight welder, and would like to do as much of the work on my own as possible (again, I'm cheap). I do plan to reach out for a few items for welding that I think are too much for me, or I'm concerned about the looks of the welds. For those wondering how I'll keep the axles squared, and matching wheels, I already use 2.5" wheel adapters to a JK pattern, so I have 17" JK wheels. The extra 5" in the rear with the spacers should almost perfectly match the WMS width of the new JK44. Items I would love input on are numbered below. Thanks in advance. And thanks for reading this super long post!

1. To truss or Not to truss: One option is to get the Artec JK2TJ axle swap kit. This includes a truss, but does not include a cradle over the diff. It does, however include the lower spring perches that relocate them to TJ/LJ spec. It also includes inner C gussets, sway bar link perches and lower control arm mounts. But, the kit is expensive. I'm curious if I could be happier with just sleeving the tubes, adding inner C gussets, lower spring buckets, LCA mounts and Swaybar mounts. I have also looked at TNT's truss which is designed to do the same thing as Artec - grind off all the mounts, weld in this truss, and it becomes a direct bolt-on axle. This kit is much cheaper than Artec's as well.

Sleeves are a waste of time and money. They offer VERY little strength increase for the effort. I've used Artec's JK one ton 60 trusses for super duty axles. They are super nice. Make it a no brainer. Plus, it will add a substantial amount of strength to the housing and probably increase its bending resistance to something higher than an aftermarket housing (at a much better price point). I have no experience with TnT stuff.

2. Knuckles: I am currently using Currie's Currectlync steering, which is basically beefed up stock inverted Y steering. I have been happy with this, and I have never bashed my tie rod, but I'm not sure how the location of the JK steering relates to my current set up. If I use stock knuckles, will I wish I would have upgraded to Rancho or Reid knuckles to get a high-steer set up? Are there any other reasons I should look at the aftermarket knuckles I've mentioned?

I don't think there is a reason to go to an aftermarket knuckle right off. The Artec trackbar bracket has multiple holes that allows you to move the trackbar up higher to match that if you choose to do it at a later date. Keep in mind, flipping your drag link to the top of the knuckle will lift it several inches and limit uptravel and potentially require notching the frame for clearance. As is, with going to cross over type steering, you'll be lifting your track bar up several inches over stock and raising the roll center (which will keep your Jeep flatter during cornering and somewhat resist body roll in general).

3. Steering: I planned on using either a Ruffstuff 1 ton tie rod, or just fabbing a complete steering set up since my drag link will need to be a different length than a stock JK drag link. I believe a custom track bar will need to be made as well, but since I'm not really a fab guy, if there is something that already exists, I'd love it but I don't really want to spend $1000 for Currie's Modular Extreme steering, although I love the looks of it.

I'd recommend calling up Midnight 4x4 in SLC. They stock tubing, weld in threaded bungs, tie rod ends, heims, etc to easily build a custom track bar and steering setup. Their tubing price is pretty much unbeatable, especially considering they will sell it by the foot.

4. Brakes: I hear a lot about the big brake conversions available for JK's. Is this necessary? I know stopping 37's or 40's takes some effort, but also remember, I don't weigh as much as a JK. I weigh about 4700. Would it be worth just using some stock take-off calipers from a JK, and just upgrade pads and rotors? Also, please correct me if I'm wrong, but I believe I can stick with my stock steering box and pitman arm? I do plan to add a redneck ram assisted box that uses a stock TJ box that comes drilled and tapped, ready to bolt in (and weld the ram bracket to the tie rod). Is there anything else I need to do to get the brake lines to work with the JK bolts? Can I use my extended braided TJ lines with some minimal modification?

Larger brakes aren't required. But if you feel your brakes aren't up to snuff after you finish, it will be easy to upgrade to either a larger rotor kit, or a full on kit with bigger calipers too. JK brakes are quite a bit better than factory TJ brakes.

5. Shafts: I am currently using RCV shafts with my HP30, and have been very happy with them. The reason for using them on my "budget" build is I kept wearing out u-joints, and I wouldn't notice they were bad until they started rattling. by then, I had already worn out my ears on the outer stub shafts making repairs more expensive than they should have been. I have also heard great things about the G2 Gold axle shafts because they have beefed up the ears around the u-joints a ton. They are still $1000 though, so maybe I might as well get RCV's if I spend that much. However, maybe I should keep the axle joints as my weaker point, if something is to break? I'm open to discuss this.

I drove a 2 door JK for a couple years with 38" MTRs. It had stock shafts in it with the 1350 u joints. I never had a problem. But I was smart about picking lines and tried to be fairly nice to them too. If you have a problem with stock shafts, then look at upgrading. I wouldn't pick shafts as a weak point per se. If you're axle you're starting with doesn't have shafts, I'd look into RCVs right out of the gate. Or if you want to be more budget friendly, I'm pretty sure that Spicer offers 4340 inner and outer shafts with u joints in an assembly. That will probably be about the same cost as getting OEM shafts with u joints.

6. Suspension links: Although due to budget constraints, I will likely save this for 1-2 years down the road after the swap is complete - I still would like to discuss link suggestions, keeping in mind this is meant to be a capable rig, but I love driving it around town, and use it 4 days of the week driving 75 on the highway regularly. I currently have short arms with Johnny Joints on all ends, and it performs well, but i eventually want to 4-link the rear and get rid of my rear track bar, and stretch the rear back a few inches. For the front I'm prone to favor a 4-link just for the simplicity of using the stock upper axle mounts, and should work well on and off road. BUT almost every complete kit available utilizes a 3-link design. Of all the complete kits available, I favor the Savvy mid-arm for its proven track record, simplicity and that I won't have to replace or modify my current skid set up, where most of the others ties into a skid/crossmember fr their frame mounts.

I run a 3 link on my rig, built right they have no issues. Savvy makes a good kit.

7. Misc brackets and other: Correct me if I'm wrong, but I assume I will need a new upper track bar bracket? If there are other items I have not considered, please bring it to my attention. I am no expert, but I'm pretty handy, so I'd love to discuss anything other than NOT doing the project

Yep, it would be best to ditch the factory frame side track bar bracket. They are a joy and a pleasure to cut off, but so much better to have a double shear bracket with some sort of heim or johnny joint at the frame. Midnight will probably have a bracket or tabs you could use to make a nice frame side mount.

 

[LJTim]

Thank you so much for your input. Confirms some of what I was already thinking and helped with some unknowns. The housing did come with shafts. Might be good to just use them until they break, then upgrade.

 

[LJTim]

Thank you so much for your input. Confirms some of what I was already thinking and helped with some unknowns. The housing did come with shafts. Might be good to just use them until they break, then upgrade.

Actually, now that I think of it, the reason I was planning on new shafts right out the gate is because I plan to go with 35 spline with the locker. Maybe some good chromos will do the job?

 

[pkrfctr]

That's interesting.... good to know, for someone considering this. On my JKU, I decided the most logical thing was to upgrade to a Tera 44 housing, was able to re-use my locker, gears, brakes, axle shafts, etc. The price for the housing was $2300, which I decided was worth paying rather than dealing with adding sleeves, replacing all the link brackets, welding gussets to the knuckles, etc.

https://teraflex.com/shop_items/jk-front-0-3-tera44-replacement-axle-housing-tf44

I wonder if you can buy a bare Tera44 housing without the coil buckets, making a JK to TJ/LJ swap easier?

Swapping your guts into the new housing is a great idea. BDS just did the same axle as you. After running the numbers and the experience our friends had, it just makes sense.

 

[Herzog]

Either way you go I'm interested in seeing the progress.

 

[RockChucker]

Actually, now that I think of it, the reason I was planning on new shafts right out the gate is because I plan to go with 35 spline with the locker. Maybe some good chromos will do the job?

If you go with RCVs in a 35 spline, keep in mind that the shaft necks down to the same 31 or 32 spline at the CV joint that the normal JK shafts run. Also, your stub doesn't get upgraded either. For a standard shaft, I can't say how much an upgrade it is, as it seems that the u joint will still fail before the shaft does on 30 or 35 spline shafts.

One thing to note....in my limited experience with seeing (not running) 35 spline shafts in a JK front axle, the inner seal has to change out and it doesn't have much of a lip and is prone to failure....many factors go into that failure, with the largest probably being poor shaft installation technique...but still. Changing seals out sucks bad. Not trying to talk you out of it, but want you to be aware. Seems like the 35 spline ARB has some weird installation procedures too in order to fit and also get the right amount of preload on the carrier bearings too. Those details are a little fuzzy.

 

[LJTim]

If you go with RCVs in a 35 spline, keep in mind that the shaft necks down to the same 31 or 32 spline at the CV joint that the normal JK shafts run. Also, your stub doesn't get upgraded either. For a standard shaft, I can't say how much an upgrade it is, as it seems that the u joint will still fail before the shaft does on 30 or 35 spline shafts.

One thing to note....in my limited experience with seeing (not running) 35 spline shafts in a JK front axle, the inner seal has to change out and it doesn't have much of a lip and is prone to failure....many factors go into that failure, with the largest probably being poor shaft installation technique...but still. Changing seals out sucks bad. Not trying to talk you out of it, but want you to be aware. Seems like the 35 spline ARB has some weird installation procedures too in order to fit and also get the right amount of preload on the carrier bearings too. Those details are a little fuzzy.

I’m not set in stone on the 35 spline. It sounds like it might be more effort and potential trouble than its worth. It might seem with my limited budget to stick with the stock shafts until I end up with an issue, then upgrade to some chromos for half the price of RCV’s? Hat way I could at least complete the swap before having to save up for RCV’s.

 

[Bart]

I'm not a JK 44 expert but I've heard there is a sleeve kit available to help with a known weak spot. Why not make up a template of what you want for a truss and Carl (iLean) can cut it out for you. Just be careful to weld slowly so you don't warp it when assembling. Good luck with the project Tim, it looks like a fun one.

 

[LJTim]

Axle swap plans are back in action. I put this on the back burner due to budget issues. I picked up a second housing, and sold the original bare bones housing to a friend. The "new" housing I picked up is packed with 5.38's (only a few months old), and an OEM locker, as well as Tera ball joints (also newish), OEM knuckles, shafts and unit bearings, as well as a Motobilt diff cover. He also threw in the OEM tie rod and drag link. I scored this for a great deal, so this kind of spring boards me a bit further ahead.

I'm leaning toward the Artec JK2TJ front axle swap kit. the only drawback I can see with this kit is, it retains the axle at stock wheelbase. If I pieced together my own brackets, I could get a little front end stretch. Not a huge deal though. Initially, I plan to stick with my current short arm suspension, but will likely eventually burn in a 3-link mid arm, or possibly a 4-link set up.

I think I'll stick with some of the suggestions above, and after finding a lot of other opinions out there that the 35 spline option is really not that important. I'm also hoping to build this axle to be "40 ready" so when I do upgrade shafts, I think RCV's would be my best option.

The only tricky things I think will be the track bar, and getting the brake lines to work. Does anyone know if the TJ lines will bolt up to JK calipers ok?

 

[skippy]

I dont like coming in and crapping all over peoples plans but a Rubicon 44 housing will never be "40's Ready".

 

[LJTim]

I got a good offer for my HP30 loaded with the locker, gears, RCV's, Currie steering and track bar, so I have decided to move forward with this swap. I know there are plenty of nay-sayers with this axle, but I have had plenty people criticizing me running 37's with my HP30, but the way it was built not only handled it, but has done very well the past few years. I think I mentioned I have 2 JK housings; one loaded, and one empty. I decided I would feel better about starting fresh with my internals. The cost is about the same regardless of which axle I use, so I sold the loaded axle to a buddy. I picked up the following today: 5.38 front and rear gears, install kits, RCV shafts, wheel hubs, Black Magic brake pads, some used JK calipers, rotors and brake lines, coil bucket/shock mounts, G2 gusset kit (which includes upper and lower inner C gussets and LCA skids, axle sleeve kit, G2 axle truss and Ox air locker. I just shipped off the rings and pinions to get cryo treated for extra strength. With this set up, and the lighter weight of the LJ, I'm still confident I will do just fine on 38-40" tires.

I will post some progress pics over the next 2-3 weeks. At this point, my only hang up is the track bar. I am not sure how I will do that, but we'll see. I am open to any suggestions with that. I know not many people have done this swap, so there might not be a lot of info on that, but I'd love to hear any suggestions.

 

[rholbrook]

I have a friend running 37s on a D44 with an LS4 behind it. He has a D60 in the rear. He isnt overly nice to it, rods it around Moab with no issues. I say take your chances. If it fails, start over.

 

[pkrfctr]

Tim, going to be awesome to see. Curious about the cyro treatmemt. Whats it cost and how much stronger does it make the gears?

 

[DAA]

Don't know anything about using it on gears, other than a lot of race rigs go that route. But I do know, it doesn't do diddly squat for a rifle barrel.

- DAA