Lower gearing is a pillar of off-road performance. It allows the engine to turn bigger tires more easily and move your 4x4 over trail obstacles. But adding gearing has often meant expense in axle gears or transfer case replacement as well as driveshaft adjustment. With Advance Adapters' new RubiCrawler for Jeeps with the 42RLE overdrive automatic transmission, you can now multiply your Jeep's low-range gears after a short day's work of installation. Even better is the fact that no driveshaft modification is needed, as the RubiCrawler literally replaces a big empty space in the tailhousing of the transmission.
With this new reduction box in front of the Jeep's stock transfer case, your choice of low ranges effectively doubles or triples (see caption 6 for info; 1-1 isn't a low range, but it is a choice), depending on whether you have an NP231 or an NP241 Rubicon case. Either way you'll now have gearing for a variety of off-road terrain.