Jeep Cherokee Ford 8.8 Rear Axle Swap - Project Ain't It Grander

Compare this to the previous photo, and you can see the coil is straighter up and down, how the bumpstop is now within the coil, and the Teraflex flat bar sway-bar links were changed to tubular ones.

Compare this to the previous photo, and you can see the coil is straighter up and down, ho

But again, I'm getting ahead of myself here. Let's go back to the bare axlehousing. All the leaf-spring brackets were cut off and the welds ground smooth. We figured the bottom design of the pumpkin was a rock catcher, so we bent up a 9/16-inch slider and welded it on. Yep, we know, you're not supposed to weld to a casting, but we did anyway. With a large acetylene torch tip, we first heated up the housing to the point where it was uncomfortable to touch with a bare hand, and then with our wire feed, we welded on the skidplate in several locations. While we were at it, we ran some short beads in the area where the axletubes join the pumpkin, as the 8.8 is notorious for spinning the tubes. We then wrapped everything in some fiberglass insulation and let it cool slowly.

When Bob Levenhagen from T&T Customs arrived at the shop, the housing was ready for him to install the axle truss that also served as an upper-suspension control-arm mount. With the pinion angle set at 15 degrees, custom coil buckets and shock mounts were set level and welded on. Also installed at this time were the upper and lower control-arm mounts, shock and sway-bar brackets, and some bumpstop plates (that later came off in a design change as shown last month).

We selected Motive Gears in a 4.10:1 ratio, along with its bearing kit, to install with our Eaton E-Locker. We have had excellent results with Motive Gears in the past and expect the same with these. Our gear contact pattern wasn't perfect, but well within an acceptable range.

This gives you a pretty good idea of the complete package under the Grand Cherokee.

Why the relatively new-on-the-market electric locker instead of a proven Detroit Locker? Street driveability on icy roads, along with (at that time) a full-time four-wheel-drive system. We talked this over with West Coast Eaton representative Scott Frary, and he convinced us to go this route. This gave us a standard open differential and-when we needed it-a totally locked rearend. It doesn't take cables or air lines and a compressor, but just a simple few wires and a pushbutton. It's not necessary to come to a complete stop to engage, but wheel speeds must be within 50 rpm of each other. So far, we don't have any complaints to pass on to him about the locker's operation.

We used the stock 8.8 cover, but added a Superlift Rock Ring to protect the ring gear and to add a bit of strength to the housing. Rebuilt rear calipers from our local auto parts store, along with turned stock rotors, provided brakes. An aftermarket steel braided hose for a lifted YJ connected the new hard lines we ran along the truss to some rubber lines that connected to the calipers.

For a driveshaft, we looked up one of the oldest custom driveshaft companies around, J.E. Reel Driveshafts, and sent them our measurements. We got back a nicely balanced shaft with a new slip yoke and equipped with the waterproof U-joints. These U-joints use a forged body that is cryogenic treated and claimed to be 40 percent stronger than an OEM joint, backed by a "U break it, we replace it" guarantee. Note we said "slip yoke." We found that the longer wheelbase of the ZJ, versus the XJ, didn't require a slip-yoke eliminator kit. Yes, we cycled the suspension through a complete shock extension numerous times with no binding. The transfer case is mounted at the original height. The suspension is set up to use every bit of the shocks' 10 inches of travel.

We played around with the sway bar and its mounting location quite a bit before we were finally happy with it as explained in Part 2. Addco was nice enough to work with us on this, and bent us a custom bar. We tried several different lengths of connecting links and finally ended up with some adjustable tubular ones from Teraflex. One of the last things we did was hook up the E-brake cables and, to our surprise, the ZJ cables were a direct hookup to the Ford rearend's brakes.

Next month, we'll cover the front axle, steering, and such where lots of modifications were made.