Under and Over Drives
FUNCTIONS EXACTLY LIKE A 2-SPEED AXLE
In 1982 the decision was made to take an analytical look at the RV'ers and other heavy towing problems. It didn't take long to realize what the industry really needed was a 2-speed axle. And quite honestly, that still holds true today. But it soon became apparent that with all the different vehicle applications and rear axle combinations required, just the difficulty of this type of installation, the idea would be both impractical and outrageously expensive. But what about a 2-speed that didn't have to be installed in the rear axle?
This would allow one basic gear box, with the various applications handled with relatively inexpensive adapters. And now, the installation could be handled by almost any knowledgeable service center. The results? The birth of the Dual Range Auxiliary Transmission.
Why A 2-Speed?
Since the late 70's the large majority of RV towing has been done with 1/2 ton - 1 ton truck type vehicles: most are equipped with three speed automatic transmissions. With towing weights as high as 12,000 - 15,000 lbs. there is no way, especially with the horsepower available, to have enough gearing for low speed pulling and still be able to cruise economically at interstate speeds. By selecting the proper Dual Range to complement your existing gear ratios, you can in fact enjoy both.
Class 'A' Motor Homes; the very popular Class 'C' version of the same; Three and Four Speed Automatics; Four and Five Speed Standard Transmissions, 4-speed Automatics for trucks and motorhomes, 4-Speed Automatic Performance Car / Street Rod / Sport Truck, 4 Speed Manual Transmissions for trucks and autos, 5-Speed Manuals, 3-Speed Automatic Truck and Motorhome, 3-Speed Automatic Performance Car / Street Rod, custom applications, and for commercial towing.