When a worn drive shaft pinion yoke is on your vehicle the level of vibration as the vehicle accelerate increases causing the performance to be less than desired by the operator. This component slips into the splines in the transmission. Most models have the drive shaft pinion yoke attached to the differential by a set of u-joints. These u-joints will wear in time and cause a banging noise to be heard when the vehicle is placed into gear. It is the small roller splines under the cap of the u-joint that wear and cause for a gap to form which is why this component become loose.
The way manufactures create a drive shaft pinion yoke is with a cast in which a steel alloy is poured. Once cooled, the component is heat treated so it will resist twisting or bending when a load is placed on it. Many of these components have a grease zert in the u-joint so the rollers in them can be lubricated which extends their lifespan. The u-joints holding the drive shaft pinion yoke to the drive shaft are held in place with c clip rings. This junction makes it possible to transfer a large amount of torque in an efficient manner.
To replace the drive shaft pinion yoke, the u-joints at the other end connecting the drive shaft to the rear differential has to be taken off. This can be done by unbolting the flange holding the rear u-joints on the rear end. The drive shaft pinion yoke can then be pulled from the transmission and the c clip rings removed so the yoke can be separated from the drive shaft. Reassemble in the reverse order.