Some day I plan on having a dream Jeep, that specific model is an 2006 LJ Rubicon with 2″ of lift and 37″ MTR tires and one of the parts that it would include is the new advance adapter Rubicrawler.
The Rubicrawler is a gear reduction box that allows you to have more selections in your gearing choice. Your standard Jeep only has 1:1 gear ratio in 4HI and when shifted into 4LO your generally have some where around 2.72 unless that Jeep of yours is Rubicon and in that case it would be 4.0:1. This means that your drive shaft will rotate once time every time the engine does one rotation in 4HI. Where as in 4LO the dive shaft will only rate once every time the engine does 2.72 rotations.
This where the Rubicrawler comes in handy because it give you additional choices for gearing. The options are 1:1, two choices of 2.72:1, and 7.40:1 for wranglers produced before 2006, and for you lucky ones with the Rubicons package the options are 1:1, 2.72:1, 4.0:1 and an impressive 10.88:1. Now some of you maybe saying that the 4.0:1 gearing is good enough, I would disagree because I think this allows you to run much better highway gears and still have a very low gear ratio. Instead of gearing my dream Jeep with 5.13 in the differentials, I will choose 4.88 and maintain reasonable gas mileage and still have a lower gear ratio than factory Jeeps.
The factory transfer-case shifter is replaced with a twin stick design in the same location that requires no modifications to the interior. The best part of the Rubicrawler is that it replaces section of the drive train that nothing more than open space. Meaning that you do not have to modify the drive shafts in anyway, or anything on the Wrangler for that matter.
There is one draw back to the Rubicrawler, which is also the reason why it is low on my dream build list, the price. The Rubicrawler costs $1784.75 and that isn’t installed, but hopefully with time demand will increase and reduce the price of the Rubicrawler. Be sure to check out the other things Advance Adapters sell because this isn’t their first great product they have produced.