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Jim's Jeep; JK rear axle build with Super 44s, ARB, and 4.88 gears.

35K views 30 replies 17 participants last post by  SubAtomicGenius 
#1 ·
It all started about a year ago when I decided to re-gear to 4.88s.
I went to the Superior site and ordered the gears and install kit. I only needed the rear set as my JK doesn't have any gears in the front :eek:
I then decided that since this is the case and based on the fact that when I do add a front diff I want my Jeep to be way beyond that of a Rubicon I should get the Superior Super 44 35 spline chrome-molly axles and an ARB locker.
This all took some time in gathering parts as I could afford. I started with the best cover I could find from RuffStuff, 3/8" steel plate. Then RuffStuff came out with a truss that would fit well with the D44 so I ordered one of those. Next up was the axle shafts that I found could be had for a better price from Superior if you order on the weekend. In december I started checking out prices on the ARB rd147 locker that is made especially for the JK with 35 spline shafts. I ended up getting a great deal from Brandon at "Don't Fear The Jeeper" so I ordered that the tone-rings and the axle retainers and nuts from him. The last thing I wanted to add to this build was the Currie Antirock which I got from Bond at "Rebel off-road" using a gift card that I won from him last year.

During this whole time of gathering parts I was watching ebay to gather the required measuring tools. I bought a digital micrometer, a dial indicator, a magnetic base, and an inch lb. dial torque wrench all for around $100. I also bought a clamshell bearing puller from DuraSolid for $150.

I am going to give a general overview of the whole process and at the end of this post I will link all of the resources I used for technical details.

At this point I would like to thank "flatlander757" for without his threads and inspiration I would have never thought this project was an option. :highfive:

The first thing you need to do anytime you remove the parking brake cables is to pin the spring inside the lever. I was able to do this with a pair of needle-nose pliers through the brushes without removing the cover.
You can see how it works here > http://www.jeepforum.com/forum/f96/oem-parking-brake-lever-study-1061720/

Next up is to remove the drive shaft at the pinion flange and tie it up to the frame. I put a strap around it and the frame before I knocked the end loose so it wouldn't fall on my face!
Remove the calipers and brake rotors then the abs sensors axle flange nuts and axles.

Now your ready to remove the sway-bar links, shocks, track-bar, coil-springs, control arm bolts, and carefully roll the housing out on a floor jack.
The pinion nut needs to be removed and here you can see the support bar that I fabricated to help with this.
I actually loosened it while it was still on the Jeep to make sure that it was possible.

These are the stock gears and carrier. Take note of the markings on the bearing caps or add additional markings to make absolutely sure they go back on in exactly the same orientation that they came off.
Mine were marked with a vertical "K" on the right side and a horizontal "K" on the left with matching marks on the flange of the housing.

Here are the old 3.21 pinion (larger) and 4.88 pinion (smaller) along with the stock Trac-Lok LSD Carrier.

After completely cleaning the axle housing using brake cleaner ARB suggests that additional oil drainage passages be added to the bottom of the axle tubes. I did this on both sides using a Dremel with a small carbide cutter.

Next you need to heat up the ring-gear for installation onto the new carrier.
I did this in my oven set to a about 200ºf.

While that is heating up I went out to the drill press and drilled out the ring-gear bolt holes to 1/2". The gears also come with 7/16" bolts and you can choose which one to drill for, you need to drill regardless so might as well go big!
I put tape over the holes in the locker as to not get any shavings inside.
Especially the little tiny hole where the air housing goes next to the bearing on the non-ring gear side.

I then installed the bearings on the carrier using a piece of 2" pipe with the face ground flat and square! :rolleyes:
The nice thing with the ARB locker is that the shims go to the outside of the bearings. So the bearings will never need to be removed for adjustments. :thumbsup:

Now that the ring-gear is nice and hot you can place it onto the carrier and align it by installing the bolts loosely. You may need to tap it down with a rubber mallet though you shouldn't pull it on with the bolts.
Mine went on easy.

I then figured out the starting shims for the pinion and came up with .0373"
I used the formula from one of the threads that I will link that uses the markings on the old pinion compared to the new pinion.
The old markings are hard to decipher though it gave me a starting point.
Installed the pinion bearing using a piece of d.o.m. 1/4" wall tube and a BFH (carefully) :) I forgot to take a picture.
The markings on the pinions are in mm. though I converted them to inches so my American mind could comprehend.
 
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#2 ·
Next I torqued the ring-gear bolts then installed the pinion without the crush-sleeve, I put in the carrier with the ARB air housing, master shims, and the Dana master shims and it was a snug fit. I installed the bearing caps paying attention to their markings and torqued them down.
I measured the back-lash and it was at .007" which is within tollerance so I took a pattern.


My first thought was "WOW it can't be this easy" and my second thought was "I'd better try it again, I think it needs to go deeper" So I took it out and added some to the pinion shims.
Here is the clamshell puller to remove the bearings. "flatlander757" has a good discription of how it works in his thread.

I went up to around .0384" and then again to .0391 for my third try.


I ended up doing it two more times and having .0426" for my final shim stack and a final back-lash of .005 - .006 measured in two places.
There were no shims needed to align the carrier and I added .005" to each side for bearing preload. I used a case spreader that I built to open the case just enough to bump the carrier into place.



At some point in there I drilled and tapped the housing for the bulkhead fitting.
Now I started putting together the axle shafts.
First on is the tone-rings, I carefully tapped them on and used the thickness of a socket to judge the depth. They are about 1/2" from the flange so they will line up with the sensors.

Next comes the retainers, the seals, the bearings, and the collers.
I heated the collars in the oven at 200ºf for about 30 min. to expand them a little.
I bet you'll never guess how I installed them!
D.O.M. tube in a slide hammer fashion :thumbsup:
You can see the differance between the 30 spline and the 35 spline shafts.


Now I went on to install the RuffStuff truss and the Currie track-bar bracket.

Welding just a small section at a time and letting it cool before moving on.
While I was welding I decided to cut off the spring perches and rotate them forward on the axle tube to better align the coils.

Next I painted it all nice and black then slid it back under the Jeep.

I then installed new Currie control arms and installed the axle shafts and brakes.
The Currie Antirock requires the the brake lines be re-located to the area next to the upper shock mounts.

The Antirock relocates the sway-bar to the area between the storage compartment and the jack compartment.

And here it is with everything torqued and the brakes bled, the new RuffStuff cover, and the diff filled with oil.

Next up is a compressor install :thumbsup:
I have 500 miles to break it in and then we'll see what a 2wd JK can really do :tea:
 
#8 ·
Good job on the gear tooth pattern, you should not have any noise or breakeage. Some shops dont even get it that good.

Jeep is looking really good im sure you stoked to take it 2 wheelin.

Now all you need is a front 4wd axle lol
 
#9 ·
very good job! I cant wait to see how this monster will turn out.

With your attention to detail it will be flawless.
 
#10 ·
Thanks' Guys :highfive:

An added note that I forgot to mention.
This project took a total of 7 days including 3 days of rain, working in my driveway under a tarp.
This pinion washer caused major havoc :eek:

The galling caused the pinion nut to completely lock up onto the pinion.
After breaking three breaker-bars and almost my cheek-bone when a pipe wrench with a three foot pipe on the handle slipped off. I ended up cutting the nut off to find the galled washer.
A new nut and washer with a little bit of anti-seize on the washer and thread lock on the nut went on without issue to crush the sleeve to the required pinion pre-load.
This episode took an extra 10 hours, make sure to use a clean washer with a little oil or anti-seize on it.
:tea:
 
#12 ·
lol live and learn.... i remember the first crush sleve i did. now i use gear oil on the washer and nut so it wont stall or sezie the nut.
 
#11 ·
Wow. Nice job :drool:

I wish I could install my own gears. I would do them next week if it only cost me parts!
 
#13 ·
Nice job dude!

Have you had a chance to test the locker yet? I installed my first ARB about a month ago and just found out it leaks, need to see it to determine what the cause is, I'm thinking the o-rings or the tube popped out of the fitting... I'm hoping the tube popped out, because I know I smeared so much wheel bearing grease over the o-rings and was stupid-careful to make sure they didn't fold over:laugh:

The pattern looks great!

I've found that most D44s set up with 0.040 to 0.044" worth of pinion depth shims, it appears this may apply to JK D44s as well, thanks:thumbsup:
 
#14 ·
Jim that's a really nice job. Good for you, can't wait too see the pics of your jeep wheeling now. Really curious also on your thoughts on the antirock. Well done!!!

Jc
 
#17 ·
Thanks for all the great feedback, It really adds a level of confidence while driving my Jeep!:)
The first 50 miles are the worst, every little noise I heard was something going tragically wrong! It was actually just a motorcycle or a helicopter flying by :laugh:
The compressor install should happen next week and I hope for no leaks.
The case spreader was great to have, I really didn't want to beat on an $800 locker with a BFH :eek:
The Currie Antirock feels great on the road and I'll give a full report after I've had it on the highway and off-road.
Here is a description of my case spreader > http://www.jeepforum.com/forum/f37/anyone-ever-make-case-spreader-1166623/#post11062289
:tea:
 
#21 ·
Question for you, and I don't want to get off topic too much and hijack this thread...but: I am upgrading my front and rear to 4.88's after my lift and tire install. Up front I am sleeving the axel and adding gussets to the knuckle to strengthen everything up. I am also going to replace my axles...only problem is I'm not sure what to go with. To be more specific, I'm unclear on what the significance of of a 30 spline axle vs a 35 spline axle. I've got D44 front and rear, and have the 4:1 xfer case (not sure the latter is pertinent info, but none the less, its included.) My goal is to have the axles as bulletproof as possible, and since I'm upgrading my gears, it made sense to go ahead and do the axles too. This would be because I'm having a 4x4 shop do it for me, as you can tell this project is a bit over my head. They quoted 9 hours on the gear job alone, and since everything was already apart, they are only quoting an additional 2 hours to do the sleeves and gussets up front.

Other question I had was about the rear end. It appears no one is sleeving the rear end. I realize this is because most of the weight of the Jeep is over the front and its not needed. I'm thinking about doing it anyway. I figured it could be done by purchasing two passenger side sleeves from the front kit and chopping them down to fit the rear. Any thoughts/opinions on this matter?
 
#22 ·
Just a guess on my part, the rear may not suffer as much twisting stress as the front with ball joints, knucles/Cs and articulation changes...also, I see D30s sleeved and gusseted, not too many D44s although the latter is the same tube and C assembly. The more splines, the shallower the spline cuts are with less stress per spline and hence the larger the solid diameter of the axle shaft...I went with RCV front axles...they are great and have a lifetime guarantee.
 
#23 ·
The 35 spline shafts are about 1/4" larger diameter than the 30 spline shafts.

They are essentially D60 shafts that have been cut to fit the JK D44. I don't know if the splines are cut shallower though the larger diameter allows for the additional splines. An ARB or other aftermarket carrier that is made specifically for this application is required to install these shafts. I chose them because there was no price difference and the ARB locker was already part of my wish list.

The axle tubes on a rear JK D44 are 3" diameter which is much stronger than the fronts which are only 2-1/2". The rear tubes are of equal length, the support brackets are closer to the ends, and the added stress of steering is not there. All of these factors play in to say that the Rear D44 is an adequate housing without extra modification, though I chose to add a truss for a little added insurance. If you decide to sleeve the rear tubes I would suggest doing an outer sleeve. The inside of a rear tube carries oil out to the bearings, sleeving the inside will restrict the flow as well as reduce the overall volume of oil in the axle housing.

I have heard great things about the RCV axle shafts for the front and will probably use these when I get to that point.
:tea:
 
#24 ·
OK, I'm on board with not sleeving the rear, and why. I guess my next question is about axels front vs rear. If I decide to upgrade to a 35 spline axle in the rear, do I need to run a 35 in the front...more importantly, am I ABLE to run a 35 up front, considering I am sleeving, will the increased diameter of the 35 spline still fit inside the sleeve? I can assume a 35 spline (if, in theory, it were the same diameter as the 30 spline) operates at a different (faster?) RPM than the 30 spline, does the increased diameter of the 35 spline shaft compensate for the difference in RPM, thus syncing the front and rear when transfer case is locked in 4wd? Is this even a relevant question?

I hope I'm not bothering too much with these questions. I'm not a horrible back yard mechanic, but this is a topic that's definitely over my head. Any additional input would be great.

Thanks,
Duncan
 
#25 ·
I haven't found a 35 spline front yet and I would guess that they would not fit in the inner sleeves, you would want to use outer sleeves only.
I just looked a the Superior site and the 35 spline rears are only for non-Rubicon axles.
You would have to call them or do some research to find what will work.
http://www.superioraxlegear.com/JK AXLE KITS-c-26.html
Axle diameter and spline count does not affect the rotational speed of the shaft. The splines are a direct connection point unlike gears which are a system of mechanical transmission.
:tea:
 
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