First Gear, Normal Left Steer Operation

TM 9-2520-249-34&P

through a port in the selector valve which indexes with

paragraph 2-50f, and illustrated in figure 2-

the clutch apply circuit.

20.

NOTE

The related mechanical functions required

2-41.

First Gear, Normal Left Steer Operation

for this travel condition are described in

(fig. 2-9)

Figure 2-9. Hydraulic system, first gear, normal left steer operation-schematic view.

a. Operational Circuits. This driving condition

forward feed. The downward movement also allows the

left geared steer clutch (driving clutch) to exhaust

uses the same circuitry as first gear, straight travel (para

through a port in the right steer valve. Simultaneously,

2-35) except that the flow of oil through the steer valves

main pressure is admitted to the lower portion of the

charges the left reverse clutch (for steering) and the

steer valve bore, regulated, and directed through the

right steer clutch (for driving).

steer relay valve to the left reverse clutch (fig. 2-13).

b. Left Steer Valve.

(2) The lower portion of the steer valve is

(1) In left steer operation, the steer control

spring loaded and produces a regulated pressure. The

shaft is rotated clockwise. This rotation causes the left

degree of pressure directed to the steering clutch, thus

steer valve to move downward.

The downward

the degree of clutch application, varies with movement

movement blocks main pressure at the upper portion of

of the steer control.

the valve and thus prevents the charging of the left

geared steer clutch through the passage labeled left

2-23