So I reached a "invest in it or junk it" decision point with the LR3. After some consideration, I decided to invest some time in it and bring it back to full operational status, and to finally undertake a project I had gathered the parts for 2 years earlier: the OEM locking differential install.

I ran into the following issues all at once:

1. driveshaft center bearing failure
2. fuel tank shield (significant) corrosion
3. brake line failure (rust in the rear brake lines)

These issues are all most easily dealt with if the exhaust, heat shields, and drive shaft are removed. And with all these pieces removed, I would then be 1/3rd of the way done to have having the prep work in place for the new (rebuild used) OEM locking differential. So... I decided to undertake the project.

Right now I've pulled the driveshaft, heat shields and I've replaced the affected brake line with copper-nickel brake lines. The fuel tank shield was shot and I'm nearly done installing an armored replacement (not OEM).

My diff builder completed the rebuild of my locking differential this morning, and I'm hoping to receive it for the weekend.

Installation of the locking OEM differential requires various conversion of various components as well as not-insignificant wiring changes. I have already installed the OEM Nav system (my LR3 was originally a bare-bones 4.4 V8 SE model), and am familiar with navigating the electrical schematics for the truck. The e-diff requires swapping in:

• e-diff controller
• new rear half shafts (the right rear shaft is very different)
• new power and communication line wiring connections
• the e-diff and controller motor

Thankfully, in preparation for this project last year I installed all the required wiring. Some pictures:

 

In the picture above with the open differential removed, you will note that the driveshaft is still attached. While the torque spec is high on those bolts (which have E14 non-standard heads), it's not crazy high (over 100 I think). Nonetheless... my ~ 350 ft/lb impact driver would not budge them. Given the shot carrier center bearing, the entire driveshaft had to be removed and it was much easier to remove the bolts at the transfer case (E12 bolt heads, came free easily with a smaller ~ 150 ft/lb impact driver) and then deal with the E14s off the car.

Free of the car, the E14 bolts required heat; they come with thread locker from the factory, but with application of a blow torch, they came right out with little effort.

Overall, the biggest surprise I have had from this project is the relative ease I have had with the various bolts. I got lucky in this regard. So far only the exhaust bolts fought me; those I had to cut off. All the other bolts came out without too much of a struggle. Even the rear half shafts, which can be difficult to remove from the hubs, I was able to get free with a simple hard rubber mallet.

 

I can tell you that a breaker bar removes those driveshaft bolts just fine. Weird, right? But I know this because twice now I have had two friends attempt to remove them with impacts and fail. I crawl under with small brakes car and they come right off. Dont ask me why this works, but I have never had an issue with them myself but I also dont use impacts.

And yeah, those exhaust bolts are crap. I end up drilling em out and just putting in simple hardware.

 

The rebuilt diff came a day early! Here's a pic. Sand blasted and repainted it for me.

I've set it in my low-lift transmission jack ready for installation in the LR3. I have some rust-proofing to do tomorrow but hopefully on Sunday I can get the diff installed and other components back in and ECU configuration reflashed.

You may notice that the diff is sitting perfectly level on the transmission jack. Two years ago when I collected the necessary parts for this installation, I took the e-diff and I made a a reenforced fiberglass cradle to hold it on top of the transmission jack. I covered the e-diff in plastic wrap, balanced it level on the transmission jack and then used insulation foam to fill the gap. Once the foam was set, I pulled the e-diff and added wood doweling for support and covered the foam with fiberglass. I think sprayed the cradle with truck bedliner to make it non-slip.

With both the rebuilt e-diff and the cradle painted black it's hard to make out the cradle, but that's how I've get it set up for (hopefully) easy installation.

 

It's raining here, but I did a few things this morning. I finished bolting in the gas tank shield and I attached the actuator motor for the diff following standard RTV gray sealant torque procedures.

Before I get too much farther documenting my re-install, allow me to give credit where credit is due here. When I'm done I'll post a 'thank you' on the Disco forums, but without this writeup here on "E-Diff Fitment" I probably would not have undertaken this work. The biggest help isn't just in having the procedure and parts list, but in knowing that it can actually be done. Same thing with the OEM Nav fitment, someone had done a writeup on how to do it, so I knew it could be done (yes, 2005 LR OEM Nav is pretty weak... but the 4x4 display on the OEM Nav is super cool).

If you are interested in this modification, the hardest parts to acquire I found were the electrical wiring components. I could not find the complete harnesses. I did find, however, that complete harnesses are not necessary. What is necessary is finding a complete set of the electrical connectors, with the most important being the e-diff controller connectors, the temp sensor connector and the motor actuator connector. To accomplish this I searched eBay for used controller and differentials where the junkyard had taken the easy path and in place of removing the connectors had just cut the wiring loom. Then, I asked the vendor to include the connectors and wiring fragments in the sale. From there I made my own wiring harness.

 

Ok, Sunday update. Getting closer, but some things are taking longer than I anticipated. This morning I bled the brakes, got the air out of the master cylinder and lines. Verified that the new brake line unions held pressure and did not leak. Reinstalled two of the three heat shields over the brake lines. The third heat shield I believe goes in between the driveshaft and the exhaust elements, so that will have to wait until the driveshaft goes in. I say "I believe", because my new gas tank shield does not have OEM heat shield mounting points so I'm completing a puzzle while missing a couple pieces.

Big victory of the day is installing the differential. The cradle worked perfectly, and with a pry bar I was able to position the differential to secure all 3 bolts. Picture of the rebuilt diff installed and gas tank shield is below.

Then I got to the axle installation. There's not a lot of room, and I'm having trouble getting the half shaft lined up to go into the diff. I'm coming in at a slight angle, and while that is OK for removal, it does not appear to be adequate for installation. I'm calling it a day and will decide whether I need to pull the air strut bolt. I was hoping not to, because I'm not a huge fan of messing with >100 ft lb bolts when I don't have to, but there may be no other way to easily line up with the differential. I'm open to any pointers on half shaft installation!

Ok, victory picture for now:

 

One of those eBay tank cradles I have been looking at. You can probably add your own shield mount points somehow. But that sure is an awesome project that so few have ventured into. Very interested to see how it all turns out. On a side note, I had a rear brake line coupling split right in half on me. Fresh install from new rear lines. I specifically ordered unions that would match the metric bubble flare nuts that LR uses at the rear soft line junctions. Just to have proper matching hardware. So I hard special orders the unions from Amazon. Only two. Thank god Napa happened to carry them too and they appear to be built a lot better. Not sire if defect or over-tightening on my part. But the read brake fluid dumped FAST.

 

Thanks, Dakota, and you are correct re: the shield, it's one of the eBay shields. I found the vendor was relatively quick with the build but they are build to order (couple week lead time) and I opted for the zinc coating. It's a solid piece, but with jacks and the transmission lift was able to get it into place solo. The "jack strap" tank support method documented on Youtube worked pretty well for me when it came to the shield swap. With the driveshaft removed, there are a couple holes in the driveshaft tunnel that are great for attaching ratchet straps (with the driveshaft in place you can just hook the ratchets on the opposite frame). The shield fitment to the gas tank appears excellent, it slipped into place and I don't anticipate shield-to-tank movement. One of the mounting holes for my application was off about about an inch but nothing a cobalt drill bit and 1 minute of drilling couldn't fix.

 

The only thing keeping me front getting that should though is pressure points. The OEM shield is contoured to the tank for support. That one is not. Or are there supports inside? If not, I would have to at least install some neoprene pads to reduce stress points some.

 

The OEM shield has a few (3?) ridges that line up with plastic ridges of the OEM gas tank. This one does not, but I was satisfied with the large amount of contact that appears to be in place. The edges also connect to the side of the gas tank so I don't think there will be any movement but I will watch for it. Additionally, there's a bit of an angle to the OEM tank (it's not pure flat) and the shield I got also has an angle (it's also not 100% flat), further helping to cradle the gas tank.

Here's a pic of my OEM shield once I got it off the car. It was in pretty poor shape. It's not super clear from this picture but the top 1/3rd or so of the shield has a bit of a 'down' angle to it.