The single speed, double reduction units that the military trucks use is a complex, very inefficient setup, but it's similar to what Mack used for a long time on their big rigs. The monster truck guys love those military surplus axles, also some of the truck/tractor pullers.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!