Advance Adapters in Paso Robles,...
Advance Adapters in Paso Robles, California, built its 2007 Jeep Wrangler JK Unlimited as an R&D test mule. To date it has assisted in R&D with the RubiCrawler auxiliary gearbox as well as the Atlas four-speed transfer case.
Every vehicle has a purpose. This 2007 Jeep Wrangler JK Unlimited's purpose is testing parts for Advance Adapters, most notably the company's new RubiCrawler auxiliary gearbox designed for Jeep Wrangler JKs and TJs.
The Advance Adapters RubiCrawler auxiliary gearbox uses a six-planetary gearset within a new cast housing. The new housing replaces the empty tail housing that mates the 42RLE auto trans to the NVG241 and NVG241OR transfer cases in Jeep Wrangler JKs, and the NVG241OR and NP231 transfer cases in Jeep TJs. Once in place it creates two low ratios; the factory 2.72:1 transfer case low ratio and the RubiCrawler 7.40:1 low ratio.
Being a test mule, the RubiCrawler JK had to be built tough all around. It not only tackles difficult trails repeatedly but is also subjected to multiple drivers with different driving styles (hard and harder; it is a test mule...). With this in mind the Advance Adapters crew installed a Rubicon Express 5.5-inch long-arm suspension system along with a set of 14-inch-travel Sway-A-Way coilover shocks up front. The arrangement clears a set of LT325/80R16 (37-inch-diameter) Pro Comp Xterrain Radial tires mounted on 16x10 Pro Comp Extreme Alloys Series 1079 wheels with 4.5 inches of backspacing.
To combat the rocks a set of Poly Performance rock sliders and a full Poly Performance skidplate system was installed. Hanson bumpers guard the front and rear of the RubiCrawler JK. The front Hanson unit is fit with a T-Max EWI 12,000-pound winch with Master-Pull synthetic winch line and aluminum fairlead. The bumper features integrated D-rings and light mounts. The rear Hanson bumper and tire carrier supports a full-size spare tire.
ARB Air Lockers and 5.13 gears are installed in the front and rear pumpkins. The front axle is a hybrid Dana 44 unit equipped with Dana 60 king-pin outers. The rear is a Dana 60 unit. A PSC steering box and pump are in place to assist steering the 37-inch Pro Comps.
This JK's time of testing parts isn't anywhere near being done. It seems that Advance Adapters always has something new up its sleeve, and we're certain that if it's a JK-related part it will be installed on this JK at one point in time before reaching final production.
Vehicle: 2007 Jeep Wrangler JK Unlimited
Owner: Advance Adapters
Hometown: Paso Robles, CA
Engine: 3.8L V-6
Induction: EFI
Transmission: 42RLE automatic
Transfer Case: NVG241, RubiCrawler
Low Range Ratio: 2.72:1, 7.4:1
Front End: Hybrid Dana 44 w/ Dana 60 outers, Dynatrac cover
Rear End: Dana 60, Dynatrac cover
Ring And Pinion: 5.13
Front Differential: ARB Air Locker
Rear Differential: ARB Air Locker
Suspension: Rubicon Express long-arm with Sway-A-Way coilover shocks
Tires: LT325/80R16 Pro Comp Xterrain Radial
Wheels: 16x10 Series 1079 Pro Comp Extreme Alloys
Backspacing: 4.5 inches
The RubiCrawler shifters fit...
The RubiCrawler shifters fit neatly in the factory transfer case shifter location and replace the factory shifter. Both JK- and TJ-style shifters are available as well as a universal-style shifter.
The LT325/80R16 (roughly 37x12.50-inch)...
The LT325/80R16 (roughly 37x12.50-inch) Pro Comp Xterrains are mounted on Series 1079 Pro Comp Extreme Alloys. With the RE 5.5-inch long-arm suspension there's ample under-fender space.
A Rubicon Express 5.5-inch...
A Rubicon Express 5.5-inch long-arm suspension system is in place and is complemented with a set of 14-inch-travel Sway-A-Way coilover shocks.
The 3.8L V-6 remains mostly...
The 3.8L V-6 remains mostly stock. With the extra gearing afforded through the addition of the RubiCrawler unit the notoriously under-powered mill becomes much more trail capable.
A PSC steering box and steering...
A PSC steering box and steering pump use an under-hood-mounted reservoir.
A T-Max EWI 12,000-pound winch...
A T-Max EWI 12,000-pound winch is wrapped with Master-Pull synthetic winch line.
A heavy-duty tie rod and drag...
A heavy-duty tie rod and drag link and PSC steering box help control the 37-inch Pro Comp Xterrains. A hybrid, high-pinion Dana 44 with Dana 60 king pin outers meets oncoming obstacles.
The transfer case, transmission,...
The transfer case, transmission, and engine oil pan are protected by a full skidplate arrangement from Poly Performance. The slick side rockers are also Poly units.
Sitting out of sight between...
Sitting out of sight between the 42RLE auto transmission and NVG241 transfer case is the RubiCrawler gearbox. It uses a new cast housing that replaces the empty tail-housing used to mate the 42RLE to the transfer case in auto trans-equipped Jeep TJs and JKs The custom driveshaft uses heavy-duty 1350 U-joints.
The Hanson rear bumper features...
The Hanson rear bumper features a hitch receiver and integrated D-ring mounts. The swing-out tire carrier supports a full size spare.
The Teraflex S/T Dual Rate...
The Teraflex S/T Dual Rate sway-bar system has street and trail settings accessed at the twist of a knob.
The Hanson front bumper features...
The Hanson front bumper features integrated D-ring mounts and counter-sunk light mounts.
A high-pinion rear Dana 60...
A high-pinion rear Dana 60 uses 5.13 gears and an ARB Air Locker. The Rubicon Express 5.5-inch long-arm system has worked well through all of the RubiCrawler testing.
Steve Roberts of Advance Adapters...
Steve Roberts of Advance Adapters navigates the RubiCrawler test mule over the company's rock pile 4WD test course adjacent to its Paso Robles, California, facility.