TM 10-3950-206-12
(3) Rotate steering wheel until cylinder rod
moves half the stroke plus approximately one inch.
(4) Loosen locknut and rotate rod end until pin
will fit through hole of spindle and rod end.
(5) Tighten locknut against rod end.
(6) Replace nut and cotter pin.
(7) Steer wheels to full left and full right
positions, and measure, at each position, the distance
between side ring of wheel and the axle frame. Both
measurements should be equal within 1/8 inch. Adjust
steering cylinder rod end accordingly, repeating steps
(1), (4), (5), and (6) above.
Figure 4-57. Steering cylinder removal.
Section XVIII. HYDRAULIC SYSTEM MAINTENANCE
4-73. General
4-74. Control Levers Adjustment
The crane hydraulic system is comprised of the pump,
a. General. The control levers are connected
hydraulic winch, control valve, slewing, lift, and boom
directly to the hydraulic valve unit by ridged mechanical
extension cylinders, reservoir, and filter with associated
linkage and should require no adjustment after
lines and fittings. Hydraulic oil is drawn from the
installation. If relocation of the lever position is desired
reservoir by the pump which is mounted on the
for operator's convenience, fellow the instructions below.
transmission. The oil is forced through a high pressure
b. Adjustment.
line to the control valve. When the lift, boom extension,
(1) Adjustment may be made at either end of
slewing, and winch control levers are in neutral position,
the tie rods between the control levers and the valve
oil flows through the valve and back to the reservoir.
spools.
When one of the control levers is de- pressed, oil is
(2) Remove cotter pin and headed pin se-
diverted through tubes and hoses to the corresponding
curing yoke to spool (fig. 4-58).
cylinder and the desired motion is performed. When the
(3) Loosen nut on tie rod and turn yoke to
limit of this motion or stroke is reached (piston rod fully
achieve desired adjustment. Turning yoke clock- wise
ex- tended or retracted), pressure built up in the system
onto the rod will move the relative neutral position of the
to approximately 1, 750 psi forces a plunger in relief
control lever up. Turning the yoke counter-clockwise will
valve section of control valve to open and return excess
lower the control lever position.
oil to reservoir.
The lift cylinder overcenter valve
Note. Regardless of the adjustment
prevents flow of oil from lift cylinder when hydraulic
the full swing of the control lever must provide
system is not pressurized, even though control valve
compete activation of the valve spools in either
lever is de- pressed. This prevents boom from lowering
direction.
when engine is not running. Refer to figure 1-5 for
(4) Align yoke with spool end and install pin
schematic diagram of hydraulic system.
and cotter pin.
(5) Secure the adjustment by tightening the
nut against the yoke.
4-59
