Advance Adapters RubiCrawler for JK Wranglers with 42RLE
In the rocks, many Jeep owners want
crawl-pace gear ratios to reduce the risk of vehicle damage and powertrain load. By crawling slowly, we can
negotiate rough, rocky terrain with better vehicle control. This minimizes wheel spin while
delivering exceptional torque.
The more elaborate methods of gear
reduction have involved dual-transfer case installations. Bulky, weighty and requiring chassis and driveline
modifications, adding an extra transfer case is a complex approach. For some, simply installing lower ratio,
low-range gearing in the transfer case has been popular—but this does not offer the same range of ratios that
an extra gearbox does.
Advance Adapters has provided an ideal
solution for owners of 2003-present Jeep Wrangler and Jeep Wrangler Rubicon models equipped with the 42RLE
automatic transmission. A “RubiCrawler” gearbox, essentially a two-speed planetary transmission, offers
direct drive plus 2.72:1 reduction drive. The gearbox fits neatly between the transmission and transfer case,
offering the driver a dramatic reduction ratio by simply moving
In addition to the
Jeep’s original low-range ratio, the RubiCrawler provides an additional reduction that takes gearing down
another 2.72:1! This means that the stock Jeep Rubicon low range reduction of 4:1 (NV241 Rock-Trac transfer
case) can be multiplied to: 4 x 2.72 = 10.88:1!
Yes, shifting from high range to low
range plus low range of the RubiCrawler, the reduction nearly triples. With the transmission’s 1st gear ratio of
2.84:1, the Rubicon model’s 4:1 low range, the RubiCrawler’s 2.72:1 ratio and a final axle ratio of 4.10:1, the
total reduction available is 127:1! Add to this the torque converter multiplication, and the torque available in
the lowest gear slots is astounding!
The RubiCrawler is well conceived.
Advance Adapters RubiCrawler system, with either the twin-stick option or a universal style shifter,
looks like a factory installation. Actually, the shifter components and fit-up pieces have an even more
durable presence than original equipment.
Better yet, the RubiCrawler fits the
exact length and space of the stock transmission-to-transfer case adapter. This means no driveshaft cutting, mounting issues or driveline problems.
Install the assembly by the instruction sheet and start enjoying an additional 2.72:1 reduction
View the slide presentation (below), and you’ll see
why I am impressed with Advance Adapters' RubiCrawler crawl box for TJ and JK Jeep Wranglers. If you need
seriously low gearing for oversized tires and severe rock crawling chores, consider this
The video is an .flv file, which opens automatically with Adobe Flash Player™ and other .flv supported programs.
A free, secure download of Adobe Flash Player™ is available at the Adobe website. For convenience, you can click
this link to access Adobe Flash Player™:
You can view this video in either the viewer frame above or in
full-screen, lower resolution format...
Note: For current
pricing and additional details, visit the RubiCrawler page at the Advance Adapters website
catalog—click here for
a direct link. The instruction sheets for various RubiCrawler applications are available at the Advance Adapters
website or you can click links below. These installation
are courtesy of Advance Adapters. They were produced by Advance Adapters for
installing the RubiCrawler crawl box into Jeep TJ and JK Wrangler models equipped with the 42RLE automatic
transmission. (Advance Adapters is responsible for all of the information and details described within these
- RubiCrawler for Jeep
JK with Integrated Twin Stick Shifter
- RubiCrawler for Jeep JK Universal Style
- RubiCrawler for Jeep TJ with
NP231 Transfer Case Integrated Twin Stick Shifter
- RubiCrawler for Jeep TJ with NP241 Transfer Case Integrated Twin Stick
- RubiCrawler for Jeep TJ Universal Style
Copyright 2010 ©
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