independent suspension arms. When one side of the
vehicle rises faster than the other, the twist set up on the
It is operated by varying air pressure in air suspension
swaybar reacts on the axle or independent suspension
bags, mounted between the axle and the frame. The air
arms, tending to keep the frame level. If both sides rise
bags serve to lower the pusher axle, force the axle
equally, no twist is set up in the swaybar.
against the road, and distribute loads evenly between
wheels. Because of a lack of inherent dampening capa-
bilities, shock absorbers also are used with the pusher
30-21. Pusher Axle. The pusher axle (fig. 30-24) is a
axle. The shock absorbers stabilize fluctuations in the
nondriving axle. It is used in Conjunction with the
air bags caused by road surface characteristics. Air
standard suspension to increase the load-bearing
cylinders are used to raise the axle, and chains are used
capabilities of larger vehicles. The axle is raised and
to secure the axle in a stowed position when not in use.
lowered by the operator using controls located inside the
Figure 30-24. Pusher Axle and Controls.