This is an optional HPI Baja Heavy Duty Differential Gear. Upgrade the drivetrain of your Baja 5B with these great heavy-duty option gears and options! In addition to stronger & more durable main diff gear and idler gear, you can also upgrade the pinion gear as well as change the drive ratio of your Baja!

Also available is an innovative pinion gear heat sink (HPI86712) which will further increase the durability of your Baja's drivetrain in race and hard running conditions!