The Ford F-250 three-quarter-ton truck is available with automatic or manual transmission and various engines, ranging from a 300-cubic-inch inline six-cylinder to several types of V-8 engines. It is also available with two- or four-wheel drive. The F-250 has a long wheelbase and uses a two-piece drive shaft with a center support bearing that holds and stabilizes the two drive shafts. The center support bearing is held in a rubber insulator, and bolts to a crossmember on the frame. Both drive shafts must be removed in order to replace the bearing.
Park the F-250 on a level, paved surface. Place wheel chocks in front of the front wheels. Raise the rear of the F-250 with a jack and support with jack stands.
Move under the rear of the F-250 and use Wite-Out to paint a mark on one of the U-joint caps. Move forward and paint a mark on each U-joint cap that is in line with the first one. You will paint a total of four marks in a straight line from rear to front. These marks must be lined up when you reinstall the drive shafts or you will have vibration when you drive the F-250. In other words, the two drive shafts must be reinstalled in the exact same position relative to each other, the transmission and rear axle as when you took it apart.
Use a wrench to remove the two bolts from each U-joint retaining strap on the rear drive shaft, where it attaches to the axle. Remove the driveshaft. Wrap a strip of duct tape around the loose U-joint caps, so they don't fall off.
Pull the rear drive shaft off of the front drive shaft. The rear of the front drive shaft is splined. The front of the rear drive shaft has a slip-yoke that fits over the splines. Set the rear drive shaft aside.
Use a wrench to unbolt the retaining straps from the front drive shaft where it attaches to the transmission. Remove the drive shaft from the transmission and wrap the U-joint caps with duct tape. Pull the rear of the drive shaft from the center support bearing. It may be necessary to tap the splined end of the drive shaft with a rubber mallet.
Use a ratchet and socket to remove the two bolts that hold the center support bearing to the crossmember. Remove the bearing, which has the rubber insulator and hanger attached to it. You can take the hanger and insulator apart to replace the bearing, but it is better to replace it as an entire unit because the rubber gets worn out.
Mount the new bearing assembly and install the bolts. Use a torque wrench and socket to torque the bolts to 50 foot-pounds.
Slide the splined end of the front drive shaft into the bearing. Mount the front of the shaft in the transmission. Make sure it's in the same position as when you removed it. Install the retaining straps and bolts. Tighten the bolts. Slide the front of the rear drive shaft onto the splined part of the front shaft. Make sure its in the same exact position as when you removed it. Mount the rear of the shaft on the axle. Install the retaining straps and bolts. Tighten the bolts.
Raise the rear of the F-250, remove the jack stands and lower it to the ground.
