Description:Reaction hubs like part # 339-3213 are used to retain the spindle bearing and center the wheel spindle to the ring gear and planetary carrier in the final drive. Cat drive train components must endure incredible torque, high impact loads, and frequent direction and gear changes. Cat designs and manufactures its transmissions and final drive components with these demands in mind. The result is a drive train that lasts longer and works harder over the life of the machine.Attributes:• Hardened steel hub• External Spline Number of Teeth: 76• Internal Spline Number of Teeth: 96Application:Consult your owner's manual or contact your local Cat Deale for more information.