Your transmission provides a means for changing the ratio between engine rpm and driving-wheel rpm to best meet each driving situation. It also trades speed for power through gearing and torque conversion. In order to have smooth starts, climb hills, or drive at highway speeds, a ratio must be used to multiply the torque (turning effort) of the engine. Most of the communication between the engine and the wheels is the responsibility of the transmission’s gears. Gears are simply a means of applying leverage to rotating parts. Transmission gearing makes more effective use of the engine’s torque and keeps the engine operating at an appropriate speed.
A desirable transmission, however, is more than just an effective grunt box. Two of the major reasons why you’d want to swap in a new tranny are a deep First gear ratio for excellent starting and crawling and Overdrive for driving at normal highway speeds. For the most demanding applications, off-roaders want better performance, durability, and rugged design.
While all of the swaps listed below are not for everyone, they most certainly are some of the most popular and provide options for replacing your worn gearbox. For detailed swap information check out Novak (www.novak-adapt.com) or Advance Adapters (www.advanceadapters.com). Both Web sites offer a wealth of transmission information.