JK front Dana 44 swap into LJ

LJTim

Active Member
Location
Herriman, UT
Tim, going to be awesome to see. Curious about the cyro treatmemt. Whats it cost and how much stronger does it make the gears?
Tim, it is typically a 30-50% increase of strength, and up to double increase of durability. The web site of the company doing this for me claimed the process makes a D30 pinion as strong as a 60. I think that is a lofty and exaggerated claim, but muscle cars and racers have been doing this for decades. It just isn't as popular in the rock crawling world (although an older 4wheeler article is what initially turned me onto the process). The popular thing just tends to build things BIGGER, instead of lighter and stronger.

Here are the two articles that initially turned me onto cryogenic treatment.
http://www.fourwheeler.com/how-to/transmission-drivetrain/129-1103-making-stock-dana-30-axles-survive/
http://www.fourwheeler.com/how-to/transmission-drivetrain/129-0705-cryogenic-gear-treatment/
 

LJTim

Active Member
Location
Herriman, UT
Gears will be delivered today. I finished chopping off the JK coil buckets, sway bar mounts and track bar mount, basically everything but the control arm mounts. I will re-use those considering the reinforcement they will all receive from the truss and the LCA skids. The real work begins tomorrow with the help of Jeromy at Pendleton Racing & Fab.
IMG_0056.JPG
 

LJTim

Active Member
Location
Herriman, UT
It has been a long undertaking, but I am about half way through the swap. With the help of Jeromy at Pendleton Racing & Fab in his spare time, we got the old 30 out of there. Several hurdles have been thrown at us that have slowed the progress a bit. It took a little longer than I had hoped to get the new gears cryo treated. Once we got those back, Jeromy went after the rear gear install. IMG_0121.JPG
Then we got the bases of the coil buckets positioned where I wanted and tacked in place. Also checked the clearance of the truss, as we knew it would be a little too wide with the massive coil buckets.
IMG_0179.JPG
After getting everything tacked in place and we were comfortable with the placement of everything, Jeromy did his magic with the finished welding on the rest of the truss, the inner C gussets and the lower control arm skids. Then we gut it hung under the jeep with a little finesse, and while Jeromy worked on getting the new 5.38 ring gear secured to the new Ox air locker, I threw a coat of paint on it. I should add, Jeromy also machined some sleeves to further beef up the housing.
IMG_0274.JPG
IMG_0278.JPG

From here, along with finishing up with the gear/locker install, I need to get the steering, brakes, and axles assembled and in place so we can get it down on its own weight. Probably the biggest hurdle of the project is figuring out the track bar. I roughly know how I want the brackets designed, but we need it sitting on it's own before we can finalize that. We'll also fab some sway bar tabs to go in place at that time as well. There was also a mishap with the new yoke for the JK pinion to the TJ 1310 joint. I was given a tcase cv shaft yoke (the oposite end of what I needed) even though my order was for the pinion yoke. So a couple more days delay and another $100, we're shooting to have the project all completed next week.
 

pkrfctr

Registered User
Location
Spanish Fork, UT
At first I thought you had that shock mounted to the top of the axle, had to zoom in to see its just hanging there. I was scratching my head for a sec. Can't wait to see it done, and want to see how the cyro gears hold up.
 

LJTim

Active Member
Location
Herriman, UT
I'm on the final stretch on the axle swap. For the record, this is more complicated than I pictured in my head. We did finally get it on it's own weight last night so we could figure out the track bar bracket positioning, which has been the worst part of the whole deal. I knew it would be tricky, but space is really tight, and getting things to clear is a serious challenge. Tacking the track bar up today, and after some flex testing with the fork lift, (hoping everything clears - pray for me) we will get all the finished welding done, as well as the permanent track bar made (just using cheap pipe for mock up). There is a slight chance we'll have to notch the frame to clear the track bar, but we'll see later today. The cool part has been making templates from cardboard, and quickly cutting them out on the plasma table to get exactly what I want.
IMG_0313.JPG
IMG_0314.JPG
IMG_0317.JPG
IMG_0320.JPG
IMG_0335.JPG
IMG_0339.JPG
IMG_0341.JPG
IMG_0343.JPG
IMG_0344.JPG
 

LJTim

Active Member
Location
Herriman, UT
Forklift testing exposed some adjustments we had to make. Coils were severely bowing, so we had to cut off the coil correction plates, and rotate them so they would actually do their job. Also had to add a bend in the track bar to clear the dif cover. Only finished welding, some small gussets here and there, and the fab of the sway bar tabs remain. Then I'll touch up these areas with some paint, and hopefully be good to go [fingers crossed]. This is the first time I have taken on an undertaking of this scale, so I'm pretty nervous. When pulling the jeep in an out of the shop a couple times to fork lift, there have been 2 loud pops when turning the wheel. I'm hoping that was just some stress on the brackets that were only tacked in place, because we couldn't find anything touching. It makes me nervous though.
IMG_0375.JPG
IMG_0381.JPG
IMG_0387.JPG
IMG_0388.JPG
IMG_0389.JPG
YFII0678.JPGIMG_0390.JPG
 

Attachments

Last edited:

Jinx

when in doubt, upgrade!
Location
So Jordan, Utah
I love this Tim! Keep up the good work and the sharing.

I am curious on your track bar. Do you need to add gussets or something to keep it from bending more?
 

LJTim

Active Member
Location
Herriman, UT
I love this Tim! Keep up the good work and the sharing.

I am curious on your track bar. Do you need to add gussets or something to keep it from bending more?
Thanks Nic. If you're referring to the track bar mounts, yes. They will both be reinforced. The track bar itself, no.
 

Jinx

when in doubt, upgrade!
Location
So Jordan, Utah
Thanks Nic. If you're referring to the track bar mounts, yes. They will both be reinforced. The track bar itself, no.
I get nervous with bent tube... it likes to keep bending, (depending on wall thickness)

It might be worth bending a second track bar to keep in the back of the LJ just in case. wouldn't take much room and could be a life saver.

Just a thought,

Look forward to seeing you next month and seeing this beast in action!
 

LJTim

Active Member
Location
Herriman, UT
I get nervous with bent tube... it likes to keep bending, (depending on wall thickness)

It might be worth bending a second track bar to keep in the back of the LJ just in case. wouldn't take much room and could be a life saver.

Just a thought,

Look forward to seeing you next month and seeing this beast in action!
It's 1/4" DOM. the piece in the pic is just for mock up. But you're right, a spare might be good to keep on hand. We have the CAD to bend another one up easily.
 

LJTim

Active Member
Location
Herriman, UT
I forgot to get photos with the sway bar/stabilizer brackets all painted up, but you get the idea. I'm happy with all but 2 things. First axle build ever was bound to not be perfect. 1) I should have looked at the level closer when initially setting up my coil plates. Once everything got all set up, there was some ridiculous forward bowing of the coils. I think the digital level we used might have been reset at a non-zero angle. We were able to resolve 90% of the issue by using a coil correction plate that Artec makes, but there is still some slight bow, but you have to be looking for it to even notice. It should be fine, but if they have to decrease my caster, I might have issues. Alignment appointment this afternoon. 2) I tired to do everything as aesthetically pleasing as possible - I'm an architect. However, when it came to the swaybar/stabilizer mounts, I was so sick of this project, that I just wanted them to function. They look like s%$^.
IMG_0419.JPG
IMG_0420.JPG
IMG_0421.JPG
 
Top