How to Change the Carrier Bearings on a GMC Pickupby Russell Wood
A standard cab GMC truck use a regular one-piece drive shaft to connect the transmission to the rear axle. However, longer trucks, like crew cab, long bed or extended cab models have two-piece drive shafts. These require a support called a carrier bearing in order to function properly. In the case of a GMC truck, the carrier bearing is located midway between the transmission and the axle. If this bearing wears out, harsh vibration can develop. To prevent serious damage to the drive train, the bearing must be replaced.
Park the vehicle on a level surface. Put wheel chocks around the front wheels. Lift the rear of the truck with the jack and place jack stands underneath the axle.
Draw a mark on the end of the drive shaft and axle where the two meet so that you can align them properly once the carrier bearing is replaced. Unbolt the drive shaft from the axle with an open-end wrench, then slide it out from the axle. Unbolt the carrier bearing from the frame with the 3/8-inch ratchet and socket. Pull the drive shaft out from the transmission and roll it out from under the vehicle.
Install the carrier bearing into the large hydraulic press and use the press to remove the old bearing from the drive shaft and install the new carrier bearing into it.
Lift up the drive shaft and slide it into the rear of the transmission. Bolt the carrier bearing to the frame with the 3/8-inch ratchet and socket. Position the drive shaft in the axle so it lines up with the marks you previously made, and install it using the open-end wrench.
Raise the truck, remove the jack stands, lower it to the ground and remove the wheel chocks.