Rear

The driveshaft or coupling shaft is composed of the universal joints (U-joints), connecting shafts, attaching flanges, and slip yokes. The number of shafts and U-joints used depends on the vehicle application.

Some vehicles use a one piece steel or aluminum, slip-yoke type driveshaft. A universal joint and splined slip yoke are located at the transmission end of the shaft, where they are held in alignment by a bushing in the transmission rear extension. The splined slip yoke and transmission output shaft allow fore and aft movement of the driveshaft as the rear axle moves up and down. This provides smooth performance during vehicle operation. An oil seal at the transmission prevents leakage and protects the slip yoke from dust, dirt and other harmful material. A second universal joint attached by two U-bolts is used where the driveshaft mates with the companion flange at the rear or an axle flange yoke on vehicles equipped with circular axle flange.

Others use a coupling shaft in conjunction with a driveshaft. Care must be taken to align the shafts as shown in the figures. The two-piece driveline system incorporates a "necked down" coupling shaft stub with a "blindspline" feature which assures positive phasing action.

All two piece driveshaft vehicles are equipped with center support bearings that are prelubricated and sealed for the bearing life.

All U-joints are of the lubed for life needle-bearing type. U-joints equipped with grease fittings should be lubricated at the specified intervals. The U-joint bearings are retained on the U-joint spiders by snap rings and U-bolts on some applications.




All driveshafts and coupling shafts are balanced; therefore, if the vehicle is being undercoated, the shafts and all open spline areas must be covered to prevent undercoating material from getting on the shafts.

Three types of driveshaft connecting joints are available on different vehicles, they are:

1. Single Cardan U-Joint.

2. Double Cardan U-Joint.

3. Constant Velocity Joint.

The Bronco rear driveshaft assembly is of the double Cardan type which incorporates two U-joints, a centering socket yoke, and a center yoke at the transfer case end of each shaft. A single U-joint is used at the axle end of the shafts.




There is only one flush type fitting for the centering device. The slip yoke only has one lube fitting. U-joints equipped with grease fittings should be lubricated at the specified intervals. They should be lubricated periodically with Long-Life Lubricant, C1AZ-19590-BA (ESA-M1C75-B) or equivalent.

CAUTION: Under no circumstances is the driveshaft assembly to be clamped in the jaws of a vise or similar holding fixture. Denting or localized fracture of the tube may result, which could cause driveshaft failure during vehicle operation.