The Tera CRD60 rearend has 4.10 gears and an ARB Air Locker. Boyd put the air locker in back and the Detroit Locker up front - the correct way to do it, in our opinion. The hubs can be unlocked, and the ARB disengaged on the highway for a completely open Jeep with great highway manners. In the dirt, the ARB can be left on most of the time, and the Detroit Locker up front makes it easy to turn. The only people who say you can't turn with a Detroit up front are those who've never had one there. Drivetrain Unlimited installed the gas-tank skidplate and fabricated the U-bolt flip kit.