Turtle Racing Drive Differential Cups . This is the "inner" or "differential" drive cup for your rear drivetrain which have both been modified with beefy steel rings by Turtle Racing. They are built to take the punishment from hard landings and high horsepower engines. This set includes only the "inner" cups, or "differential" drive cups only. It's recommended you run both inner and outer cups for maximum strength.

If you run hpi stock or heavy duty dog bones you will need to grind down the pins on each end to be slightly shorter. But for the ultimate in strength and reliability, you should consider using the DarkSoul "Meaty" dog bones.