Most drive shafts are one continuous unit which connects the vehicle engine's transmission to the rear differential. However, drive shafts on some large vehicles and performance automobiles are two piece units with a center bearing (aka carrier bearing) to support the shaft roughly half way from the transmission to the rear axle differential. If this bearing fails, removing it and replacing it with a new one is a straight forward project for a home mechanic requiring nothing more than common garage tools and a bit of effort.
Use a jack to raise the vehicle high enough to allow you to get under it with room to work with your tools.
Place the vehicle on jack stands positioned precisely under the axle or frame rather than having it supported by the jack.
Use a work light to enable you to easily see your work under the vehicle.
Use a piece of chalk to make a mark starting on the side of the transmission, continuing onto the drive shaft which will help you reposition the shaft exactly as it was when you reinstall it. Drive shafts connect into transmissions with a splined shaft which will only fit in one way, but the index mark will help you find that exact position when reinstalling the shaft.
Use a piece of chalk to mark the universal joint where it attaches to the yoke coming out of the rear axle differential so it can be reinstalled exactly as it was when the drive shaft was removed.
3 Use a piece of chalk to mark the plates which connect the forward portion of the drive shaft and the rear portion of the drive shaft so they can be reinstalled exactly as they were originally installed.
Remove Drive shaft
Disconnect the drive shaft center bearing from the vehicle's frame using the appropriate sized socket and wrench. On some vehicles the bearing block bolts thread into nuts which are welded to the frame; on other vehicles, the block is bolted to the frame with a standard, two part bolts and nuts.
Remove the bolts which secure the universal joint bearing to the yoke coming out of the rear axle differential.
Wrap and secure a strip of duct tape around the caps of the universal joint bearing to prevent the caps from falling off while you are handling the drive shaft.
Pull the entire drive shaft to the rear extracting the splined shaft from the rear of the transmission. Once it's free, move the drive shaft to a workbench.
Remove Old Bearing
Remove the bolts from the plates which connect the front part of the drive shaft to the rear portion of the drive shaft. Set the rear portion of the drive shaft aside. Secure the forward portion of the drive shaft firmly in a vise.
Remove the center nut which holds the front connecting plate onto the shaft on which the center bearing is positioned.
Tap the old center bearing off the shaft with a hammer. If you need to direct the blows to the where the collar of the bearing touches the shaft, use a brass-ended punch to prevent nicking or scratching the shaft.
Install New Bearing
Apply a thin layer of grease on the bearing shaft to make the new bearing slide on more easily.
Push the bearing onto the shaft to get it started, then use a hammer to force it all the way into position. Use a brass-ended punch if you need to strike the bearing hard; direct blows could scratch or nick the bearing collar or the shaft.
Reassemble the drive shaft, then reinstall it onto the vehicle by reversing the removal proceedure. Use the index marks to insure it's reattached exactly as it was before it was removed.