Crown Race Gears are built to handle the abuses of 1,000+ horsepower and massive tires in hill-n-hole racing.
Mud trucks, hill-n-hole racers, and swamp buggies run massive tires and often push north of 1,000 horsepower that, when combined with aggressive use, create unimaginable stresses on the axle's ring and pinion gears. Each time their oversize tires impact a dip or a bump, the drivetrain and axles bind up as they apply torque to the tires. Then, when the tires pass through the obstruction, the drivetrain unloads temporarily before binding up again when the tires regain traction. These forces, multiplied by big tires and big power create extremely high shock loads that cause the gear teeth to flex. For gears without the proper toughness attributes, these bending forces will begin to form micro-fractures that quickly grow to become cracks and ultimately lead to gear failure.
Crown Race Gears are purposely designed, engineered, and treated to withstand such abuses by starting with a steel alloy that is heat treated and then cryogenically treated to be as tough (flexible) as possible to absorb shock loads, yet have a very hard case (surface) to ensure a very long wear life. This ideal gear case hardness transition is difficult to achieve, yet it is the key to making a ring and pinion set hold up to years of hill-n-hole racing and mud drag racing.
Because micro-fractures are the main cause of gear failure in large mud trucks, Crown Race Gears go through two separate shot peening sessions that increase the gear density in critical areas. This process has shown to improve the usable life of gears by about 75%, and has become a standard requirement for most aerospace components.
In addition to heat treatment and shot peening, Crown Race Gears are cut using 5-cut helical gear geometry that uses a sliding motion to transfer power through the gears instead of a pushing force that stays at the center of the ring gear teeth where it increases the likelihood of pitting and micro-fracturing. Then, to take full advantage of the 5-cut gear geometry, Crown Race Gears are REM ISF finished for an aerospace grade smooth surface that, when used with full-synthetic gear lube, reduces friction and power loss by almost 40%.
By maximizing gear toughness, creating a desirable case hardness transition, shot peening the tooth roots, and using an aerospace gear finish, Crown Race Gears are stronger, tougher, and more efficient than any other off-road racing gears available today, making them the top choice for mud trucks, hill-n-hole racers, and swamp buggies.