A 2-piece driveshaft is used on all models through 1976. Some 1977 and later models use a one piece driveshaft with U-joints at each end.
The 2-piece driveshaft assembly consists of the front shaft, the rear shaft, a center support bearing and U-joints and yokes. The rear end of the driveshaft is attached to a companion flange at the rear axle through a U-joint, and, at the front, to the mainshaft by means of a sliding yoke. This arrangement provides for fore-aft movement of the driveshaft as the truck moves up and down. The center of the driveshaft is supported by the bearing attached to the underside of the truck.