[LSU_TJ]

ARB Locker Install in Rubicon D44 Axle

Well I got the infamous Rubicon OEM Air Locker failure and decided to go with the ARB locker as a replacement. First I want to thank the guys at Randy’s Ring and Pinion and specifically Blue, for all his help and very quick shipping. I have no connection with these guys and this is the first time I have done business with them and I will definitely do business with them again. They have excellent customer service and pricing. This is intended to supplement the detailed instructions provided by ARB and provides some tips on what I did on my install specifically in a Rubicon Dana 44 axle. While this was written with respect to my install it may help others in the install of their ARB locker. These tips are what I did and may or may not work for you but hopefully will save someone a lot of time that I spent working through some of the issues during install. Do this install at your own risk. This is a pretty technical install but not bad at all if you are good with a wrench and can take your time and follow details very closely.



To start, the ring bolts for the Rubicon D44 are 7/16” so the holes in the ARB housing need to be drilled out with a 29/64” bit. I used a drill press and plenty of lube and then chamfered the holes with the next size up bit. This is some pretty hard steel and you will have a time if you try to do this with a hand drill.

You can see in the previous picture that I originally pressed this bearing down flush with the end of the housing like the original unit was but this was not far enough down. If you look close you can see the flat seat at the bottom that it needs to be pressed down to. I originally used a flat bar so I could only press it flush. To push it down all the way to the bearing seat I had to get some kind of tool to act as a bearing sleeve press so the housing could slide up inside of it and press down on the inner bearing race.





I used a 4wd Spindle Nut Wrench. This worked perfect as a press tool for this bearing and was about $9 at Autozone.





The next hiccup was how tight the ring gear was when trying to get it installed on the new locker. I first coated the ring gear seat on the locker with Anti-Seize and then put the gear in my high tech powder coat oven (i.e. toaster oven from Wal-mart) for 1 hour on 200 degrees. It dropped right on at this point. Do not forget to get all the reference measurements needed for shims in the ARB Instruction manual BEFORE you put the ring gear on. Ask me how I know…..



I used red locktite on all ring bolts and torqued them down to 80 ft/lbs. There was some discrepancy on this figure as I was seeing 80 or 100 ft/lbs on the specs on the forum and checked with Randy’s Ring and Pinion who said it was 55 ft/lbs for the ring gear bolts on the D44. The original bolts were hard to break so I decided to go above the 55 figure and went about in the middle with 80 ft/lbs on these bolts. I also tightened them in a star pattern and numbered the pattern I used in this picture.



I got the diff cover gasket surface cleaned and prepped with a razor blade then an air angle grinder with a cup brush. This got rid of all that old RTV sealant and gave a good smooth surface to re-apply the RTV gasket maker to.



For the air line I decided to use the hole the original air line used in the top right inside of the housing. To get the old connection out just remove the hose and tap with a hammer on the flare fitting from the inside and it will just pop out of the diff housing on the outside top where the old air hose was connected. This hole is too small so you will have to drill this out with a 7/16” drill bit then tap it with a 1/4” NPT tap to thread for the new ARB air line fitting.



Be patient with the tap and clean the threads out to make sure you don’t have any shavings left in the new threads.



After I ran the tap about 3/4 of the way through I did a trial fit of the brass fitting and it kept stopping after a few good turns in the new threaded hole in the diff housing. I thought something was wrong with the new threads so cleaned them out again and ran the tap in and out a few times to check the threads.

.

[LSU_TJ]

All seemed good and then I noticed the threads were not the problem why the brass fitting was stopping. It was bottoming out on the housing so I used my dremel to grind a little off of the housing where it was rubbing.



Now it goes all the way down smooth.



The next issue I had was where the copper line came out of the Seal Housing and you have to bend it outwards to get it as close to the diff housing without rubbing as you can. The Seal Housing is notched but the Rubicon locker had another original Master spacer, which I had to re-use to maintain proper spacing, which is not notched so it was rubbing a spot on the copper line where you have to bend it outward. To fix this issue I used my dremel to grind out a notch that matched up with the one on the Seal Housing so I can lay it down without rubbing.



I rounded out the edges so I did not have any sharp edges that could rub a hole in the copper air line.



Now there is some extra room for the air line to lie across.



You can see here where it completely lays through the slot in the OEM Master Shim. You can also see where I used a paint pen to mark the original bearing braces. You need to re-install these exactly as they came out, taking note of which side they came from and which way was up. This is very important.



Here is the air line pushed through the brass fitting. I cut it back with an air powered reciprocating cut tool but the dremel with a small cut off wheel would have probably worked better.



Here is how I routed the line inside, giving it some slack in case I need to change anything later and would need more copper line to push through.



I have checked the backlash with a digital Dial Indicator and have it at .007” which is within spec. I only added two .002” shims to the left side to achieve this backlash value on mine. The OEM specs I found on the forum showed backlash values to be between .005-.008” and Randy’s Ring and Pinion have this as .006-.010” for the acceptable backlash range. So I am about right in the middle and should be good. I did not mess with the pinion gear so that should be good.

Time to stab the axles and drop this thing back on the ground and take her for a spin.

Ok, here is where the fun began. I have Alloy USA Chromoly axle shafts and stabbed the right axle that came out of the right side before the job and torqued it down, no problems. Next I stabbed the left axle back where it came from and just started the four nuts on the backing plate. I then turned the hub and the right hub turned in the opposite direction, perfect. As I started to tighten just the first nut on the backing plate and long before torquing it down the axle locked up and would not turn at all to access the next three nuts through the access hole in the hub. It was obvious that the axle was hitting something and was at least 8mm or more from being flush. The weekend was over so I spent the next few days on the phone with the folks at ARB and Alloy USA’s rep to find out what was going on. The consensus finally was that there was a possibility that the axles were different lengths and the internal offset is different in the ARB compared to the Rubicon factory locker and the axles would need to be swapped. I did not notice a difference in the axle lengths when they were standing side by side during this install but was also not looking for it either. I pulled the right axle back out and sure enough….



It was a good 14mm difference in length. At this point I swapped the axles and everything bolted right up and torqued down perfectly. So remember this THE SHORTER AXLE GOES IN THE LEFT SIDE with an ARB install. Now time to drive it slow and carefully at first to listen for any strange noises.

Dropped her to the ground and took her for a spin. All now!!! Runs great and no strange sounds. Looks good, done.

Overall this was not a bad job at all. Tearing down a differential is one of the few things I had not attempted yet because of all the hype about how technical it is dealing with gearing. It is no more technical than rebuilding an engine block. Just takes time, patience, and attention to details. I can say now that if I want to do a gear change to 4.56 or 4.88’s I know who is doing it….. Just need a Dial Torque Wrench and I am ready for changing a gear set. Little more involved dealing with the pinion gear but can be done no problem. Love spending the weekend learning something new!!

.

[TheMasterChief]

Good stuff. Gonna be switching my carrier out for an ECTED soon.

[spyder6]

good write up. when/if my locker goes i'll be going with a detroit though

[mrblaine]

Originally Posted by LSU_TJ

You can see here where it completely lays through the slot in the OEM Master Shim. You can also see where I used a paint pen to mark the original bearing braces. You need to re-install these exactly as they came out, taking note of which side they came from and which way was up. This is very important.

Very Nice write-up, but you're a funny guy with the paint marker.

Look at the left side of the seal area where the diff cover bolts on. See that letter U laying on it's side that's stamped there? Move your eyes across to the bearing cap and you'll notice another letter U laying on it's side stamped in the bearing cap.

If you look at the other side, you notice another letter U standing up. It's not readily visible in your pics due to lighting angles, but if you look for it, there will be another letter U matching it's orientation to the one on the seal surface that's stamped into the bearing cap. That's why they are there, so you know which side and which is up.

[LSU_TJ]

So you're actually Mr. Hawk....

[Jerry Bransford]

Very (!) nice writeup, I'm thinking we may want to put it into the FAQ. Thanks LSU_TJ!!

[gman98]

I've done quite a few ARB's and I always check to make sure it locks (and no leaks) by using a rubber tipped blow gun pressed into the brass fitting in the housing before connecting the air line and buttoning everything else up.

[LSU_TJ]

Originally Posted by Jerry Bransford

Very (!) nice writeup, I'm thinking we may want to put it into the FAQ. Thanks LSU_TJ!!

Glad to contribute. If it saves one person some time/headache installing this unit then it was worth it. Just got back into the jeep thing after about a 10 year stretch with ATV's. Hopefully more to come.




Guess I need to change the sig now.


.