Chapter 12: All J Products/Jeep 4x4 School Street Legal YJ Rock Crawler

When we started working on the YJ book, we decided that building a YJ would be good source for material. Shopping for a YJ turned out to be a bit of surprise. Due to the popularity of the JK and the high resale value of used Jks and Tjs, the YJ prices were skyrocketing. Luck intervened.

We were doing an event for a tire company when a film crew from another tire company rolled in All Products. They had a YJ and needed all of the fluids drained out for part of the video project. They planned to roll the YJ over so it could be recovered (with minimal damage). We wondered how that could possibly relate to a new tire launch video, but oh well! The All J crew drained the fluids and the video crew trailered the YJ out on a a local trail. The YJ showed up in a BFG promo video a couple of months later. The video showcased the new BFG KM3 mud terrain tire. The rolled YJ appeared for about one second in the final cut. Damage to the YJ was minimal. The crew was from the Pacific Northwest and didn't relish the thought of hauling the YJ on the long trek. They owed All J for some work and we worked out a trade for the somewhat rough four banger YJ. It ran fairly well but needed some work. Which really didn't matter since we had plans to change nearly everything in the driveline and suspension.

We decide to conduct the build in two phases. First we would utilize the stock drivetrain and engine with a spring lift in a spring over axle configuration. We chose the Rubicon Express seven inch spring over lift with their monotube shocks. This lift required a slip yoke eliminator and custom driveshafts from JE Reel Drivelines. This install was fairly simple and easily accommodated 35 inch Nexen Roadian MTX mud terrain tires on Raceline steel wheels. To really make use of the 35 inch tires, we needed to change gear ratios in the stock Dana 30 and 44 axles. A gear ratio of 5.13 along with the AX5 transmission first gear ratio and the 2.73 low range ratio in NP231 transfer case gives a crawl ratio in the mid 50 range. With he front sway bar disconnected, axle articulation is good in the big rocks.

The original steering components were pretty worn so we replaced the steering drag ling and tir rod with heavy-duty parts from Rugged Ridge. The new power steering pump from Omix-ADA replaced the leaking original unit. The original rubber brake lines were replaced with longer braided stainless steel lines from Rugged Ridge. Engine and transmission mounts needed replacement with parts from Rugged Ridge. Old radiator hoses were swapped with new parts from Omix-ADA. The exhaust kit from Omix-ADA includes header pipe, catalytic converter, muffler, tail pipe, gaskets, clamps, and isolators. The cracked exhaust manifold was replaced with one from Omix-ADA. Steering box and gas tank skid plates from Rugged Ridge were adde for the intial phases of the project. Phase two would see the YJ become a mean extreme rock crawler.

Since tire testing was part of the project and we posses several sets of 5 on 5 bolt pattern wheel, we used Rugged Ridge wheel adapters on the stock 4.5 inch on 5 bolt pattern hubs to 5 on 5 wheels.

The stock four banger leaves something to be desired in the best of circumstances. With our tired 2.5 liter engine, we were looking for a cool engine swap. We considered a GM LS swap because All J had one on hand, but after some debate we decided that a Cummins 2.8 crate turbodiesel would be awesome, but too pricey for our budget. We settled on a 5.9 liter (360 CID) V8 from a and Cherokee ZJ. Novak Conversions supplied the engine mounts for the swap into the YJ chassis.

To maximize rock crawling capability we wanted to convert the suspension to a coilover setup which also allowed the wheelbase to be stretched from 93 inces to 102 inches to improve stability. We used the Rock Krawler Trail Runner Stage 2 system with remote reservoir shock absorbers. The sport tuned coilovers provide 14 inches of travel front and rear 2 5/8 RRD Remote Reservoir Racing Coilovers provide great on road ride and off-road performance The RRD shocks are fully adjustable and tunable. The rear coil over mounts are frenched into the frame ahead of the axle enhancing the off-road capability.

The lower control arms made from 2 inch od 7/16 inch wall dom. The front upper third link arm made 1.75 inch .120 wall dom steel tubing with weld in bungs. The front suspension is a three link with a rear triangulated 4 link suspension. A 1/4 inch thick steel skid plate mounts long arm brackets while a weld-on cradle on the rear axle provides control arm mounts. The 2.625 inch diameter RRD remote reservoir racing coilovers at the front and rear allow 14 inches of travel. Currie AntiRock Sway Bars control body roll.

This package offers about five inches of lift and great articulation for the 37x12.50*17 Nexen Roadian MTX tires on Raceline Monster beadlock wheels.

To handle the rigors of the Hammers trails in nearby Johnson Valley, we selected the Currie RockJock 60 VRX axles with 5.38 Motive ring & pinion gears with ARB Air Lockers and 35 spline Currie axles. The axle tubes are 3 1/2 inch diameter, .375 wall DOM steel tube. Currie two piston calipers and 13.25 inch rotors in front and Rubicon calipers on rotors in the rear supply plenty of stopping power. A slip yoke eliminator from Ruged Ridge is used on the transfer case and the custom driveshafts are from JE Reel Drivelines.

The stock steering was not enven a possiblity for the extreme rock trails in our local mountains and at the notorious Hammers in Johnson Valley, only an hour form the All J shop. We considered the complete PSC heavy-duty traditional power steering, but decided to go all out. We ended up with the PSC full hydralic system which eliminates the steering box. A power ram move the tie rods when the steering is turned and a control actuator valve is engaged. The steering ram is mounted to the Currie RockJock 60 VXR axle housing with an Artec Industries truss and brackets supplied by PSC. We weren't sure what mto expect from the feel of the steering but it is actually easy to adapt to. The only real downside to this system is the lack of steering if the engine dies or the power steering pump (or serpentine belt) fails.

Considering the abuse our project YJ experienced prior to our purchase, many exterior and interior items were either missing or damaged. Other items did not fit the extreme rock crawling look we wanted.

On the outside, we added the Rugged Ridge XHD Bumper Tire Carrier rear bumper and the Rugged Ridge XHD Front Bumper with a winch mount and a Warn Zeon 10S Platium winch with synthectic winch line. The newest Warn winch is delight to use. We were a little skeptical until we used it. The wireless remote is easy to use, has a great range and operates the clutch on the winch. There is not clutch release lever. The wireless remote holds a charge quite well, but is important to keep it charge via the USB plub.

Omix-ADA offers nice replacement quarter panels which were needed to replace the damaged quarter panels form the staged rollover for the video. Other casualties of the rollover included the headlights which were replaced with lights from Omix-ADA and fender flares. Rugged Ridge provided their All-Terrain 4.75 inch Fender Flare Kit. Bent and broken mirrors were upgraded with new parts from Rugged Ridge.

Other worn and neglected items on our YJ project need replacement. the cowl vent cover was replaced with the Rugged Ridge part. The steering wheel was quite worn and upgraded with one from Omix-ADA. Corroded hood latches were swapped for new latches from Rugged Ridge. Years of neglect ruined the original carpeting. Rugged Ridge makes a deluxe carpet kit which made the flooring look like new. To protect the new carpet form the grit and sand of extreme four wheeling, the Omix-ADA All Terrain Floor Liner Kit was installed.

The top was missing from our bargain YJ so we installed the Rugged Ridge XHD Black Diamond soft top kit and XHD Black Diamond. Since we had no hardware we used the Rugged Ridge Jeep Wrangler Replacement Soft Top Hardware Kit. For summer use, A Rugged Ridge Summer Brief top is ready for action. The original seats were trashed. Rugged Ridge again cam to the rescue with their RRC Reclinable, Black Off Road Racing Seats. We also added their Ultimate Grab Handle kit from RT Off Road.

The Rock Krawler coilover suspension kit does not allow room for the stock gas tank. We used a19 gallon custom fuel tank to accommodate the four link rear suspension. The tank was originally out of a TJ and was made for Nth Degree Technology who also made the gas tank skid plate. A custom belly pan skid plate was fabricated at All J Products. Safety features were rounded out with a Rock Hard 4x4 bolt in roll cage covered with a Roll Bar Cover Kit from Rugged Ridge. The driver and passenger restraints come from Rugged Ridge and Omix-ADA..

the first run on our highly modified orange YJ rock crawler proved to be well beyond expectations. We traveled for a half hour to the Cougar Buttes area of Johnson Valley on Chicken Rock, Bull Frog and Calk Walk trails, all very challenging rock crawling venues. The YJ made up and down every obstacle with ease. The lockers were never engaged. Not once did we encounter wheelspin from the Nexen Roadian MTX mud terrain tires. Overall, we are very please. More extreme trails are on tap for future adventures.