Front Axle
The front axle (4) is a one-piece, steel-forged I-beam section. The outer ends (6) of the axle center are machined to accommodate the steering king pins and the knuckles. King pin inclination is built into the knuckle end. The front axle is available in five weights:
| • | 3 675 kg (8,100 lbs) |
| Option (FL1 |
| • | 4 090 kg (9,000 lbs) |
| Option (F43 |
| • | 4 545 kg (10,000 lbs) |
| Option (FM6) |
The steering arm (6) and the tie rod arms (10) attach to the knuckle (20) with bolts or are attached through keyed holes in the knuckle with keyed castle nuts. The stepped king pin (12) is located in a steel-backed bronze bushing (13) at the lower end, and in a high-angle tapered roller bearing (3) at the upper end. The lower bushings are greased through fittings in the lower covers; excess grease is purged through skirt-type seals. The upper bearing is packed with grease during assembly.
The upper bearing is pre-loaded against a thrust washer (4) by placing a shim or a spacer between the inner race and the axle beam king pin boss, then by tightening the pivot pin prevailing torque locknut to a specified torque.
The upper bearing cover (1) is press fit into the knuckle. The lower cover is a gasket and a flat plate retained with bolts.
Front Suspension
The springs are tapered leaf type with an eye-and-compression shackle. All springs and shackles are rubber bushed. Vehicles with 14,600 and 16,000 pound gross axle weight ratings have multileaf springs with an eye-and-compression shackle.
The spring assembly rests on the shock mounting bracket, and both are attached to the front axle with U-bolts. A rubber bumper is attached to the frame. This bumper hangs suspended above the spring center.
The stabilizer assembly consists of a shaft attached to the center of the I-beam, with two arms attached by a flat plate linking to a frame crossmember. The stabilizer assembly is bushed and mounted in rubber. The stabilizer does not require lubrication.
Twin-tube shock absorbers provide damping. These shock absorbers are mounted vertically behind the front axle. The top and bottom attachments are pin type with rubber insulators. The shock absorber upper mounting is a stamping attached to the frame. The lower attachment is a forging between the axle spring seat and the spring.
