TM-5-3805-254-14-P-2

TRUCK, DUMP, 20 TON, 6X4, ON-OFF HIGHWAY 71,000 GVW, IHC MODEL F-5070 (CCE)

TECHNICAL MANUAL; OPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT, GENERAL SUPPORT AND DEPT MAINTENANCE MANUAL (INCLUDING REPAIR PARTS INFORMATION AND SUPPLEMENTAL MAINTENANCE INSTRUCTIONS)

JUNE 1980

TM-5-3805-254-14-P-2 - Page 644 of 894

TRUCK SERVICE MANUALSTEERING

Actuating Piston

The actuating piston moves in the gear housing.

There are two ports on the outside diameter of the valve

which direct the oil flow through the piston. The valve has

about 1/32" linear motion within the piston, which permits

the edges of the ports to seat against mating edges on

the inside of the piston, directing the oil flow to either end

of the piston.

Output Shaft and Pinion

One side of the piston assembly is equipped with

teeth (rack) which are engaged with the pinion gear on

the output shaft. When the piston moves back and forth

within the housing, the gear turns, providing the rotating

action of the pitman arm, which is connected to the

steering linkage.

Relief valve plungers (adjustable stops) are

provided at the bearing cap and cylinder head location

which automatically unload the hydraulic system when

the wheels are turned to either extreme direction. This

protects the mechanism from undue strain and damage

in that a clearance is provided at the wheel stops, Fig. 4.

DISASSEMBLY

1. To drain oil from the steering gear assembly,

disconnect the return hose from the pump and

turn the steering wheel completely to the right

and then to the left. This will remove most of the

oil from the housing.