MAINTENANCE OF FORKLIFTS - OD1660 - LESSON 1/TASK 1
not be used with vehicle speeds in excess of 10 miles per hour. For
convoy operation or extended periods of use in the two-wheel steer
mode, it is recommended that the safety detente be locked in, to
prevent accidental activation of the four-wheel steer.
The four-
wheel steer capability is controlled by a system of links located
under the driver's compartment. The separate modes of steering (two-
wheel steer, four-wheel steer cramp, and four-wheel steer oblique)
are controlled by the three-position hydraulic cylinder anchored on
the pitman which acts upon the intermediate link.
A valve, located
in the link, is anchored on the rear cross shaft bellcrank and the
wheel forward end of the intermediate link, which in turn controls
the action on the rear wheel steering by the hydraulic pressure.
CAUTION
Do not operate the forklift with the cockpit
compartment doors open.
This precaution will
prevent injury to personnel.
b.
Steering Gear Assembly.
(1) When the operator turns the cam to the left or right, by
turning the steering wheel, the stud of the inner lever is moved
through the groove of the cam (worm).
This, in turn, rotates the
lever shaft and provides angular movement of the steering gear pitman
arm.
Whenever the operator's effort at the steering wheel exceeds
the preload of the centering springs and "hydraulic reaction," the
control valve is actuated and hydraulic power is applied to provide
the driver with power steering. The action of the steering system is
hydraulic with mechanical follow up.
The pitman arm is splined to
the main steering gear lever shaft and provides required feedback to
the operator, giving some "road feel" and a steering reference point.
Mechanical disadvantage is such that manual steering is not feasible.
The engine must be running to provide hydraulic pressure for the
steering system.
To force the steering system (with the engine
not running) may result in damage to the system.
This steering
system incorporates a hydraulic control valve on a single stud cam
and lever mechanical steering gear. The front steering operates off
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