• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

My build... long arm lift, JK axle swap, stiffeners, whole 9 yards


NAXJA Forum User
Albuquerque NM
Hey guys please be patient with me on this one. I have searched forums for years on various builds and learned tons from them and this is the first time i have finally decided to post myself and contribute to the available knowledge. Im doing a full build on my jeep all at once and i searched and searched and only found 2 similar write ups online so i wanted to share my experiences as well. So to start I have an 01 4 door XJ with 75000 miles on it and of course the 4.0 and an auto. After many boring nights at work and talking for hours about how to build my jeep i settled on doing the rusty's 8 inch long arm lift, swapping in JK axles, and everything that goes along with it. As the jeep sits im about half way done. we will see how much i manage to write about tonight. Also as soon as i can figure out how to attach pictures i will attach a good amount of them.

To start with i know that the unibody is weak on these things and that mine still has low miles and a lot of life left in it so i wanted to strengthen it as much as i can before i destroy it. so i picked up rough stuff frame stiffeners, both the main sections and the front section stiffeners. That being said i decided to start with the front section because i wanted to wait to do the rear main section until after i finished my long arm lift knowing it could affect things. So i had picked up a 110 welder and after putting on a few pieces i was unsatisfied with the quality of the welds :doh: i knew they where terrible. I then picked up a 220 welder for a steal of a deal and used a .75" hole saw to drill holes through the stiffeners but not the frame so i could weld that area with the 220 unit. Much better welds where achieved! Once that problem was solved i kept on pushing. so the ruff stuff front section frame stiffeners are 3 pieces. i decided to only install the front 2 at first because the 3rd piece covers the access hole to the upper control arm bolt and knowing that i will being removing my upper control arm i wanted to leave the rear section off until i had removed the upper control arm and the bolt that goes along with it. when putting on the front 2 sections of the stiffeners i learned your going to want several good sized c clamps and that for the 2nd or middle section you need to bend it in at the middle to match the curve of the unibody frame rail. also you will need to remove your shocks, springs, and track bar mount to gain all of the required access to do this. Any how long story half way short the front 2 sections got burned on.

Now for starting to work on my new axles. I picked up axles out of a 2013 JKU. i was at the right place at the right time for the right price and figured sure why not. now yes i researched this a lot and it can go both ways, i know what a lot of people will say about those axles. however for my sake of argument i will be installing a high pinion dana 30 up front that has a larger ring and pinion gear than the stock XJ dana so so in that regards its stronger. Also i decided to install press in Nitro Gear sleeves that almost double the thickness of the axle walls and also install a truss. so in all regards the axle housing will be tons stronger. I also really like that it will make my wheel base 5 inches wider.

First things first i decided to install the press in sleeves first so that just in case i where to warp the axle tubes while welding the truss on the sleeves would already be in there. and due to the added thickness of the sleeves it would really help to prevent warping of the tubes. to install the sleeves we cooled them in dry ice for several hours while we fully disassembled the axle and center section being careful to keep everything separate and labeled so we would know exactly where it came from. We sprayed a lot of cleaner inside the axle tubes and then used wire to tie a wire brush into the handle of my floor jack and used that to reach all around inside the axle tube and clean it up as best as possible. we followed that up by pushing a much of towels and cleaner through the tubes almost like cleaning a gun. After we where done with that we pulled the first sleeve out of the dry ice and begun to pound it into the axle with a bearing driver and a sledge hammer. While driving in the 2nd sleeve the bearing driver shit the bed. it was completely destroyed and could no longer be used. however i discovered that we where able to flip around my 36mm socket for the axle end in the unit bearing and that the drive end fit perfectly into the sleeve and that it would act as though a bearing driver. i then took a piece of pipe i had laying around and put it in the socket and drove the last sleeve the rest of the way in. we did another complete set of sleeves this way the same day. :party:

Now about this truss. I bought a TNT customs truss to convert a jk axle into an xj as well as their supper beefy lower control arm mounts and i must say im very impressed with it. it is very beefy. however one thing you will want to know is that to use this truss you need to have adjustable control arms upper and lower. when the truss is installed your upper control arm mounts are raised roughly a few inches. Now to install the truss i followed tnt's instructions. I bought a digital angle finder and put it on top the upper ball joint and you rotate the axle backwards giving it 5 degrees of positive castor. then you set the truss on the axle perfectly level. tnt says that is how you properly locate the truss and the upper control arm mounts attached to the truss. now at this point i had to grind and shave down a few spots on the axle and to truss to make them mate up nicely. In the process of getting the truss onto the axle i had to remove the C gussets that the previous owner of the axles did a beyond terrible job of installing. When the truss is done i will trim the c gussets to work nicely with the truss and reinstall them. The truss still always slightly rocked a bit so we clamped it down nicely with 2 c clamps. The next step was to burn the truss onto the axle taking care to not over heat it in one are to much and warp the truss or axle tube. Only weld about an inch and a half at at time and take care to alternate areas kinda like doing a torque sequence as well as take breaks now and again to allow all of it to cool back down.

If your still with me at this point major cudos to you! I'm sorry this has turned into a book but i really wants to be detailed with this as while planning out my build i wasnt able to find as much information as i would have liked, my only hope is that this all helps someone in the future.

Just a touch more information about the truss. The TNT Customs truss converts all the mounts, axle side track bar mount, shock mounts, sway bar mounts, and coil spring perches to where you need them to be for your xj. Now you will need an adjustable track bar as well. however something i really like about the truss is that the coil spring perches are adjustable. you can move them forward up to 1.5 inches to lengthen your wheel base!

Now here is where i will reveal some of my mistakes... i got to thinking :doh: :doh: :doh: big mistake. lol ok so what i did was with my old axle still bolted to the upper and lower control arms i measured the castor angle as the jeep sat and wrote that down. i then removed the axle and set the new axle under the jeep at the same exact height on the jack stands as the old axle. i then bolted up my upper control arms to the upper control arm mounts on the truss and here is where i figured id be really smart :doh: i set the new axle to the same exact castor angle as the old axle so its sitting in the jeep exactly the same as the old axle. so for not really a bad ideal... Then i figured i would just raise the lower control arms into place to mock up the lower control arm mounts and be sure that i properly located them in the exact correct spot so that everything would be as correct as possible and my castor angle when all said and done wouldnt be far off... :doh: well i was wrong! My stock lower control arms where about an inch to an inch and a half to short. i was majorly confused and spent 2 days trying to figure out what i did wrong :doh: at this point i called tnt customs and they asked me to email them pictures... so i did. while waiting for their response i measured the height of the upper control arm mounts from the center of the axle tube on the old axle and compared that to the measurements on the new axle and found that the upper control arm mounts are now a few inches taller. now everything made sense because with the axle rotating off the upper control arm mounts to get the same castor angle it would push the bottom of the axle out more than normal explaining why my stock arms where now an inch to an inch and a half to short. :doh: thats the last time for a little while that i decide to go off script and start thinking for myself instead of following instructions :doh: at that point tnt called me back and said hey your problem is you need adjustable control arms, this kit doesnt work with stock arms. now knowing that my train of thought and logic was sound, i was just missing important information. anyhow i have sense decided to follow the instructions for the lowers and measure the angle of the truss and install the lower mounts at the same angle. i havent done it yet as ive moved to other areas of the jeep but it looks easy enough and will be getting to it shortly.

If your still fallowing me at this point seriously thank you a lot!

I just became a member right now because i want to share the information ive been learning. I have made more progress than this however im going to stop here for the night and call it quits until tomorrow or the next day. now i have no clue how to attach pictures to here or why i cant upload pictures to my profile but i promise as soon as i can i will flood this thing with pictures so you can see what im talking about!

Sent from my SM-G900V using Tapatalk
Well I really wanted to run 37's and down here we mainly do rock crawling. Me personally I'm not a fan of stuffing a giant tire on a low jeep and trimming a ton and then adjusting bump stop to have no up travel left. I wanted to still have full up travel and a ton of flex with the big tires. I didn't want to drag belly over every single rock.... so after a bunch of discussing 8 inches is what I landed on.... and there may have been a little of "you won't run an 8 inch lift, no balls, you won't do it" there may have been some of that. Lol however to make it more stabil I'm making it wider as well. The new axles are 5 inches wider and I'm going with 4 inch backspacing on the rims I think

Sent from my SM-G900V using Tapatalk

I just installed the TNT truss on a TJ rubi 44, and came to the same conclusion with the adjustable control arms. They really should mention that
Before I start using it to much in going to box and gusset that upper control arm mount. Today I'm working on installing the front end of my lift kit, the new cross member and my transfer case, we will see how far I get

Sent from my SM-G900V using Tapatalk
OK for more of an update. I have 99% of the parts on hand to do my build so we started with the rear. I was all out of regular jack stands so I borrow a set of frame stands and went off the jacking spots for the rear bumper with the stands. We dropped the axle and the stock sway bar. I haven't decided if I want it yet. Dropped the leafs, shocks, and shackles and to my luck all the bolts came out just fine. Installed the new shackles, and leafs and reattached the axle to discover the e brake cable is not near long enough so I disconnected that. On a side note I have no clue yet how I'm going to hook up the e brake on the new jk axle when I put it in or how I'll run my brake lines yet but I'll figure it out. One thing at a time. I also decided to do bar pin eliminators with the rustys monotube shocks I went with. Major pain in the butt! We had to get very incentive with the vice and a very large punch to get the bar pin eliminators properly onto the shocks. We bolted that all up but left the bottom end of the shocks off because it won't be going anywhere until I get the jk axles back with gears in them and can mount them up. We also dropped the T-case to install the SYE.

Sent from my SM-G900V using Tapatalk
Today we went out with the hopes of getting the front done. I painted the completed frame stiffeners with under coating so it will last a while. We removed all the factory control arms and cut off the factory lower control arm mounts from the frame and removed the tra bar and mount and moved the axle that was just sitting there out of the way for a while. We started mocking up the plates that channel the frame rails for the long arm center section and of course my jack stands where in the way. We decided to put the now unused frame stands under the frame rails way up front but had an issue of how to jack it with no axle to jack off of. I had a friend bring a second floor jack but it turned out to be little. The other problem was the transmission wasn't mounted so we needed to raise that with the jeep. Here is where we got very inventive. We put the old cross member under the trans with a 2x4 on top of it to hold the trans up. We then made a large stack of wood on the passenger side to set his little floor jack on and put my big one on the drivers side. Our theory was this way we could raise both sides of the jeep at once and the transmission at the same time. We tried to do one side at a time and it wanted to walk off the jack stands. So we then put a 1 foot long piece of old rail road tie in top of my jack and then bridged the gap between the 2 Jacks with 3 2x4s also giving us more height and jacked them up against the cross member and started raising the jeep up. It was super sketchy but it worked! We raised the jeep and the transmission all at once! I'll post pics of the sketchy setup.

The tire sitting in the picture for looks is my spare 35 for my truck. Any how we mocked up the outer plates and bolted then on and drilled the required holes. We then went under the jeep and hole sawed the required 1 inch holes into the frame rails for the inner plates and sleeves that go into the frame rails. This was a major PITA! And if course they weren't perfect the first time so we had to ream them out a bit to get the inner plates and sleeves in properly. Once we finished that it started to rain and it was getting dark so we packed up. Any how here are all the pictures of today's work and how it currently sits.

And that's how it sits as of now and my current progress.

Sent from my SM-G900V using Tapatalk
Here are the inner plates and sleeves finely fitted into the hole sawed holes. I'll get a better picture tomorrow

Here are the holes we had to drill from the outside of the frame rail

Hopefully soon I'll get the T-case installed, the new cross member in and the plates that channel the frame rails the rest of the way installed so I can attach the long arms and finish the suspension.

Sent from my SM-G900V using Tapatalk
I am going to weigh in even though my opinions carry no weight.
I love the start of this build how ever... I don't like the lift height. My old xj had 2.5 inches of lift on 35s (44 front 8.25 then trooper rear) my zj has 3.5 (same springs taller spring pads) sitting on Superduty tons. And clearing 37X12.5s the stability gained in the rocks of a lower lift is amazing and very very beneficial to all aspects of wheeling in my opinion. You have the fab skills so I would think a 4.5 and doing a flat belly will be much more beneficial to you. But once again I love the build.

Sent from my 0PJA2 using Tapatalk
This is my first real build so I wanted to do like 75% bolt on suff 25% fab stuff. As I progress in my wheeling and my fab skills I'll learn what I like and don't like and possibly change things. I will say I'm not a fan of dragging belly over everything though.

Sent from my SM-G900V using Tapatalk
I had a belly pan so I never paid it any mind. And if you push the limits you will start to drag no matter what your lift is.

Sent from my 0PJA2 using Tapatalk
O yea I know I'll still drag on big enough stuff. I just don't want to be that guy that's a turtle and drags tons over everything and needs to be pulled because I'm dragging to much on belly. Like I said I'll run this for a while. A year or so and then decide if changes are needed. Idk if I'll work on it today. My main wrenching buddy has helped me on mine like 5 days out of the last week or so and he asked if we could work on his today so I owe it to him to work on his instead. Lol

Sent from my SM-G900V using Tapatalk
Nice build man. I just did this exact swap. Jk d30 and d44 out back. Eaton elockers. The tricky part is gonna be steering but I used a jk tie rod. And a xj/Tj synergy drag link and stock pitman arm for now. I think a waggy pitman will get lock to lock though. The jk pitman has a slight curve and for turning right it works but not left. Just a heads up.
Woowoo I read in another forum that if you trim an inch of the threads off of the jk drag link so you can thread it further into the adjusting sleeve without bottoming out that it will work. However I think you need to ream the taper out a little bit in the xj pitman arm. That's what I'm going to try until I can make a custom one. I'll post in here what I end up doing

Sent from my SM-G900V using Tapatalk
Woowoo can I ask how did you route your rear brake lines and hook up the e-brake? I haven't figure out how I'm going to do that yet.

Sent from my SM-G900V using Tapatalk