gearcase

The Rollermatic was unique in that instead of using an oil-filled gearcase, metal and urethane rollers transferred the power within the mechanism.

The shocks, gearcase bumpers, end links and a few other small parts are yellow on the Bullhead; these same parts are red on the Clod Buster.

Power then went to a longitudinal drive shaft in the center of the frame that drove the outboard axle on each powered truck through bevel gears in an enclosed gearcase riding on the axle between the truck frames.

This new driveshaft housing was three inches shorter which in turn lowered the motor's center of gravity on the boat which helped turning ability, reduced the strain on the boat's transom and motor's clamp brackets, and decreased underwater drag while increasing top speed as less gearcase was below the boat.

Not unlike other Harley-Davidson engines, the unit construction left and right engine cases split vertically, and formed four cavities: a center front crankcase, a center rear gearbox, a right side cavity gearcase for the timing train, where the four camshafts are housed, and a left cavity for the three row primary drive chain.