Project FleXJ
XJ Makeover, The Buildup of Flo Short Cuts
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The Crack
the Crack

By: Bart Jacobs - 6/2000

I had a very capable XJ, locked front and rear, 5.5" of lift and 32" Swamper radials. We had done almost every 4 and 4+ trail in Moab, and the Little Sluice and True Old Sluice on the Rubicon; so why was I not satisfied with this very trail worthy Cherokee? Maybe it was pride, or perhaps stupidity, or maybe the fact that I kept hearing about XJ owners dumping their grocery getters for more hard core rigs. Whatever it was, something inside me knew there was hard core potential in the XJ and it needed to be exploited.

True Old Sluice
True Old Sluice

Don't get me wrong, the XJ is a great off road vehicle that can do amazing things with minor lift and tire upgrades, but when it comes to hard core wheeling they are passed over for a myriad of reasons. The first I can think of is they're very sheet metal intensive, the second very obvious reason is they have the uni-frame construction, and the third, well, there's that darned hard top. But despite all the pitfalls, for some reason I felt I had something to prove when I decided to go hard core with an XJ.

While contemplating the rebuild I decided that the complete XJ makeover would need to be done in three stages. The first stage would include a custom 8" lift that would accommodate 35" tires, Dana 44 axles, and custom steering. The second stage would include skid plates, 4 to 1 t-case, front bumper with winch, beefier lockers, and a full roll cage. The third stage would bring the project all together including all the body work with a color change, and a 4.5 stroker motor.

XJ Makeover, Phase 1

I knew the Dana 35c and reverse cut Dana 30 were weak links in the XJ, especially when combining them with larger tires and lockers, so the first item of business was to locate stronger axles. The axle plan was to include 4.56 gears, a Detroit in the rear and an ARB up front. Originally I bought a Model 20 rear end from a Metric 1 ton Comanche, with solid axles and a broken 4.10 ring gear and then started to find parts. Matt at Rocky Mountain High 4x4 (RMH4x4) told me he had a completely rebuilt, drum to drum, Dana 44 from a Scout II, with 4.56 gears and a LockRight locker. When I started adding up costs it became clear that the 44 was going to the better buy and the LockRight could be used for a while and upgraded to a Detroit down the road. One drawback to the Scout 44 was it was almost 2" narrower than the stock 35c but maybe I could live with that for a while, NOT. I ended up getting 1.25" spacers from Motor Sport Technologies in California, that carried a guaranty and liability insurance on each set.

Next, the front axle. It needed to be a beefier axle than the reverse cut 30, have a drivers side diff, accommodate brackets for control arms and coil springs, and be approximately 60" wide. Again I referred to Matt and he suggested an early Bronco (EB) 44. Finding one of these in a short time period proved more costly than I would've liked, but the 1999 Easter Jeep Safari was only 45 days away and time was of the essence. I found an EB 44 housing with a set of 3.55 gears, no axle shafts or anything from the outer knuckle on. Cutting and grinding the old V control arm mounts off the housing was a major pain but after several hours of work the housing cleaned up nicely. We put 4.56 gears in and an ARB, and I traded the 3.55 gears for an early ARB compressor. To accommodate the new steering we took a Chevy right outer knuckle and machined the top flat, then drilled and tapped holes for the custom RMH4x4 steering arm. Because of availability I used a Grand Wagoneer knuckle for the left side. From there we used late Bronco spindles, rotors, calipers, and hubs to get the 5 on 5.5 bolt pattern to match the rear axle.

44 Brackets
Mounting the new
Rubicon Express brackets

To accommodate the coils on the front axle we used the newly released Rubicon Express (RE) TJ bracket kit. I got the second kit RE produced and we had to do some customizing to beef it up (apparently the first kit failed) and to locate the left upper control arm bracket in the right place on the EB 44. We calculated bracket angles from the old Dana 30 and then transferred them to the new 44. We had to use caster as the starting point so the pinion ended up lower than I would have liked. Once the angles were found we tacked welded the brackets onto the 44 and then measured and remeasured. After everything was completely welded we measured one more time and then took tolerances . We ended up with closer tolerances on the 44 than the factory brackets were on the Dana 30.

The suspension was the easy part of the project. For the rear I located a set of Alcan custom leaf springs packs and custom shackles that would give us 8 inches of lift after settling. For the front I went the economical way of simply adding 3 inches of spacers to the top of the 5" Tera Flex springs. This was temporary but achieved the right height and the spacers actually acted as a bump stop.

The control arms posed a different problem altogether. I had been running a set of custom Tera Flex lowers but wasn't sure if they could be adjusted long enough. It turned out that the RE front axle bracket kit rendered an extra half inch and we mounted it a bit higher on the axle tube. The upper control arm axle brackets also was a half inch higher so that would help with angle and length of the upper arms. We special ordered a set of Tera Flex upper arms that were unassembled. We then fit the axle in place with the lower arms attached and measured the upper arms for length. Then it was just cutting to size, welding, and powder coating and we had the upper arms done.

Testing the new steering

The steering came next and this is where having a mechanical engineer for a friend really payed off, especially when they have with a mandrel bender, mill, and an industrial drill press. We dropped the XJ on the ground and began measuring. We used 1 1/4" od, 331 wall, chromoly DOM stock for the track bar and tie rod (ouch, $.90 per inch and we used over 8 feet), then used some solid 1" chromoly stock for the drag link (because we ran out of the other material). These were cut, drilled, and tapped for the ball joints and tie rod ends. Originally we used the RE bracket for the axle end of the track bar (pictured), but later found that the angles were too far off, so we fabbed a bracket with a higher mounting point that gave us much better angles and eliminated the bump steer problem.

Playing on Prichett
Moab, Utah

With the front end in place we mounted the new 35x12.50x15 Goodyear MTs on the 5 on 5.5 Eagle alloys and set the XJ down again to measure and set the rear pinion angle, and then welded the spring perches and shock mounts on. With this done we could measure and finally order the drivelines. From there is was installing the RE extended brake lines and finishing all the little details like bleeding the brakes, installing the compressor, switches, and air lines for the ARB, changing fluids and all the little things you always skip and hope you'll remember so you can get back to them.

Yellow Hill on Prichett
Moab, Utah

These upgrades worked amazingly well and the inaugural break in run on Prichett Canyon proved Phase 1 to be a success. Even with the success of this kind of a project you almost always find things you would have done differently and these are the things on the list that either have been changed or are on the list. I've already explained (and installed) the taller axle mount for the track bar to get better angles and eliminate the bump steer. In the future I'll be exchanging the (Grand Wagoneer) left outer knuckle on the front axle for another Chevy flat top. This will accommodate the next generation RMH4x4 steering arm and we'll be moving the tie rod up almost 4 inches. When we do that I'll be removing the inner knuckles on the axle and rotating them for better pinion and caster angles. The last thing will be replacing the coils and spacers in the front with full 8" lift coils. I've attempted this once and the new full length coils were too long and way too stiff. I'm currently waiting for National Spring to wind a replacement set for those.

Update 4/1/02

Project FleXJ had to be parted out after being rolled a couple times.

Acknowledgements for Project FleXJ go to:

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