Both the P72 and the P92 chassis use a leaf spring and solid rear axle suspension system. The rear axle assembly is attached to multi-leaf springs by U-bolts. The front ends of the springs are attached to the frame at the front hangers through rubber bushings. The rear ends of the springs are attached to the frame with shackles that allow the springs to change their position while the vehicle is in motion.

Ride control is provided by two identical shock absorbers that are mounted between the frame and brackets attached to the axle tubes.