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Eaton E-locker install into Dana 44

So, you want a selectable locker without the hassle of a compressor and leaky air lines, or a cable that won't fully engage your locker??  Well… an Eaton E-locker is for you.

The Eaton E-locker is a 12 volt electromagnetically operated selectable locker that is fairly easy to install, and works great!!  The install is straight forward and with a few tips, a home mechanic with a the right tools can install one of these with little trouble. Though the instruction manual is well written, it is not specific to the model of locker that I installed.  Apparently, there are two styles of E-lockers, and while similar, the installs differ somewhat.  Eaton does take the time, and space to point this out, but as I said before… my instructions were somewhat hazy in a few areas.   Hopefully, I can clear these gray areas up for anyone installing an E-locker into a D44 in the future.

First off, a detailed tear down is not included in the Eaton manual due to the broad range of differentials meant to be covered.   This will specifically cover installing an E-locker into a Wagoneer Dana 44 front axle (that happens to reside under my Dodge Raider seen here). 

(Visit the TrailShot Galleries for more pictures of the Eaton E-Locker install.)

You’re going to need to jack the front end up, and set it on some 3-ton jack stands.  If you don’t own a set, go buy some.  They’re cheap, and will keep your axle/vehicle from crushing your ribcage, and killing you. (Being killed or maimed is a bad thing).

Get your drain pan ready, and pull all the bolts holding the differential cover on EXCEPT the top 2, or 3… Just loosen those up.   Pop the cover loose with a flat head screwdriver, or small pry-bar, and let it drain.   Fully remove the cover after the majority of the fluid has drained out.   It should look something like this though you may not have a Spool

You’ve got to take the spindles off, and axle shafts out to remove the old differential and this is where most of the difficult work it.   

After you get it secured on jackstands, pull the wheels off, and then remove the manual locking hubs, OR Hub slugs.    Mine has factory Jeep hubs, and they remove with allen head bolts on the outside, and 2 snap rings for the internal parts.  One of the snap rings is an inside type, and the other is outside type.  This is what it all looks like when it comes out.  

Once the hubs are off, you need this special socket.

Remove the outer locking nut, then fish out the inner nut retainer(dental pics, hooks, magnets, cussing, hammers, and chisels are sometimes required for this) , and remove the inner nut.   The brake disk, and hub assembly will now pull off.   Be careful to not drop the outer bearing in the dirt when you remove this.   Next up, the spindle has to come off.  There are 6 small nuts holding this on.  (Notice the safety shoes in this picture.)

Remove those, and hammer the spindle and brake caliper bracket off gently.   Now you are ready to pull the axle shaft out, and drag the differential end through the dirt that has accumulated inside your axle tube.  Pull both axle shafts out in this manner. (be sure to clean the dirt, and debris out of the differential side splines of the axle shafts before re-installing them)  

After both shafts are out, remove the drivers side tie rod from the spindle, and hang it up on the pitman arm with a zip tie.  Though the differential can be removed with the tie rod in place, the modifications necessary to the housing will not be able to be made with it in place.   At this point, you should check the backlash of your gears with a dial indicator.  It should be somewhere in the range of .0004 to .0012.   Any more than this, and you possibly have worn out bearings, or improperly set up gear set.  I did not check my backlash because it’s not been long since I set my gears up, and I know everything is in good shape.  

Now on to the differential removal.   

When you pull your main caps off of the differential housing, you will need to mark them, and NOT get them mixed up. The housing is line honed with these caps torqued down on it, and they are matched to it.  It’s just like line honing the crank bores on your new engine.     I personally use a common center punch, and put one dot on the top of the left cap, and one corresponding dot on the housing above it, and two dots on the right cap, and two dots on the housing above it.  This is only my method.  Some people use letter or number stamping kits, and others have their own methods. 

Pull the main caps, and set them aside.   You will possibly need a pry bar (especially if your set up is fresh, and has low miles on it).   Remove the differential by prying it out.  A special tool called a case spreader is made for this, but it’s often cumbersome, and more of a pain to use than it is worth.   Just get your pry bar, and pop that old diff out of there.   Make sure you keep your bearing races organized, and replace them to the correct side.   

Take the old differential to the workbench, and place it beside the new E-locker.

You’ve got to transfer the Ring gear, Case bearings, AND the bearing shims.   These shims are critical to case preload, and backlash setup, so you defiantly DO NOT want to mix these up.   I’m fairly lucky to have access to this awesome tool. 

It’s a differential bearing puller, and it works great.   (You can remove bearings, and re-use them without this tool, but it is difficult.   I recommend brass drifts, a large hammer assortment, and a vice capable of holding the case steady while you hammer on the inside race.   With my spool, it would have been easy to tap the bearings off with brass drift, but if I were removing them from an open differential case or this locker, then it would have not been so easy).   Here are some close ups of of how the puller works.

SO… Remove the bearings, AND shims on one side, and press them onto the E-locker with your “3 ton” shop press.

(If you don’t have a shop press, try and find a socket that will fit on the inner race, and tap them on with a hammer.   You can also use a brass drift, and work it around the perimeter of the inner race to tap it on).   

Remove the bearing, and shims from the opposite side of the case, and press them onto the other side of the E-locker.   Next up is swapping the ring gear over.    

Pull the ring gear off of the old differential (or in my case spool).  An impact wrench makes quick work of the bolts, and you will probably have to hammer the ring gear off as it is a semi press fit.   Slip the ring gear up onto the E-locker, and start 2 bolts to line up the holes.   Coat the other bolt threads in Red Locktite, and install them.    You will possibly have to draw the ring gear up onto the locker, and this is normal.   

The E-locker is large around the center section, and this inhibits the use of an impact socket to tighten the ring gear bolts.   The instructions supplied by Eaton said to use an open end wrench to tighten them, but I found this was not sufficient.   These bolts need to be torqued to 80 ft-lbs, and I was not comfortable with using an open ended wrench for the job.   I had several options.  Grinding to clearance the locker around the bolt heads.  Use the wrench, and not be satisfied with the torque values.  Modify a socket to fit in the small space provided.  

I ended up getting the thinnest socket I had available, and tapping it down flat on top of the bolt head with a hammer, and then holding it down as I torqued the bolts.   This seemed to work very well, and I was happy to be able to get the bolts torqued down without using an open end wrench, or grinding on my new locker housing.  

Be sure to use plenty of Red Loc-Tite.  My Mentor has a huge supply that he has been using since 1970 or so.

After getting the ring gear, and bearings swapped over to the new locker, go ahead, and stick it in for a test fit.  You need to find the ideal location for the half inch hole needed for the two wires that actuate the locker.  Be VERY careful to not strike the electromagnet with anything.  (Don’t hit it with your hammer)  You will possibly have to hammer on the outer bearing races depending on how tight your case pre-load is.

Check the clearance on the two tabs of the electromagnet retention bracket, and make sure they are not binding up on the housing in any place.   When you start getting the locker close to fully seated, check these tabs more frequently.   You do not want this piece binding up.   It needs to be free floating, and move easily.    I had to grind some material out of my housing to get my electromagnet bracket tabs to stop binding.   I used an air powered grinding wheel, and went at it slowly.   The iron on these housings is relatively soft, and easy to grind or drill, so go slow, and try not to remove too much material.   Stay away from the flat the bearing cap mounting surfaces.  These are flat for a reason.     Also, stuff a rag over the top of the pinion gear( I know I did not, but I should have)… Lots of nastiness will be flying around that is bad for bearings.  

After you get the electromagnet retention tabs free floating in there, take a look in the upper drivers side quadrant of the housing for a good spot to drill the half inch hole for the wires.  My optimal spot was JUST behind the cover sealing flange, and just to the drivers side from the vent tube.   Center punch the outside of your housing, and remove the locker.  Get out a big drill.   I used a half inch Milwaukee holeshooter.   I also had to put a jack stand under the frame of my truck, and lower the drivers side of the axle down to make room for the drill.   I also tried to get away with using the smaller 29/64ths bit that the instructions recommend to use if going through thinner metal for a tighter fit, but after the hole was drilled, I could not get the grommet through, so I stepped up to the half inch bit, and finished it off.   Here you can see the hole I drilled under the Vent tube.  There is a silver screwdriver tip pointing to it. 

Time to get out the vacuum with patented copper pipe nozzle technology.   Use this to suck up the metal shavings that you just created, and then move to the axle tubes.   Clean as much dirt, and crud out as you can.  This will keep it from being stuffed into your housing by your inner axle shafts.   

Dust the grinder shavings out of the housing, and hose it down with some brake parts cleaner to get it spotless.   After it’s clean, install the locker, put the main caps on, and tighten those down.   Check the backlash, and make sure it is the same as when you started.    If it’s not, you’ve got a problem.  If it is too tight (# is too low) , shim it away from the ring gear.  (Too Loose??) Shim it back towards the ring gear. 

Hopefully, your backlash will be right where you left it, and you can stick the wires, and grommet up through your new hole, and install the weather pack connector onto those two pins.  The hole will be tight, and this is good, so you may need to pull it through by grabbing it gently with some needle nose pliers.  Also, some gear lube probably would not hurt. 

Look closely at the connector, and there will be four tiny rectangle holes.   Two of them are for the pins, and the other two smaller ones (offset from the center) are holes for the de-pinning tool.   Orient the locking tabs on the pins to correspond to the de-pinning tool hole, and stick them into the connector.   You should hear a click from each one if it seated properly.   Go ahead, and re-assemble everything,  and then we’ll talk about wiring the electrical part up.  Don't forget the gear oil!!!

Eaton has the relay, and wiring for the E-locker all wired up with a quality relay, and plenty high quality wire.   I chose to mount my relay under another relay on the drivers side inner fender well of my raider.   The Japanese like to have lots of boxes, doodads, and widgets in their engine compartments, so there are plenty of open bolt holes that are just the right size.   I mounted it under my AC compressor relay.

The gray one is the E-locker Relay.    

There are three connections to make to the truck - one ground, and two positive.  I wired both of the positive wires directly to my positive bus even though Eaton recommends that one go to switched ignition.   (I like the option to use my locker even if the truck is off.)  I bolted the ground wire inside the truck to the brake pedal support, and drilled a hole in my dash to mount the round pushbutton switch.  You also have to cut the two activation wires to the correct length, and crimp them to the relay with the supplied butt connectors.  The wiring was very simple, and easy to carry out.