The SANDCRAFT Patent Pending Driveline Race Collar was designed for the extreme off-road riding conditions. With the stock driveline your vehicle is using a slip yoke at the rear transmission output shaft. The motor is rubber mounted which is loading the driveline while under aggressive driving conditions. The driveline is designed with a pressed fit bearing onto the stock carrier bearing shaft. In extreme conditions it will pull out and disable 4-wheel drive capabilities. Don’t let this happen to you! Our racer driveline collar can be used with the stock carrier bearing but is HIGHLY recommended with our upgraded GEN3 carrier bearing.