Second Gear, Pivot Right Steer Operation

TM 9-2520-249-34&P

Pivot Valve (normal land steer position).

Right Steer Valve.

(1) In normal steer position, the valve

(1) In right steer operation, the steer

directs second-, third-, and fourth-signal pressure to the

control shaft is rotated counterclockwise. This rotation

bottom of the steer relay valve. This pushes the valve

causes the right steer valve to move downward. The

upward where it indexes with ports to charge and

downward movement blocks main-pressure oil at the

exhaust the proper clutches for the desired steering

upper portion of the valve and thus prevents the

condition.

charging of the right output clutch. The downward

(2) In normal steering, the vehicle will

movement also allows the right output clutch to exhaust

"pivot" in first and reverse gears-one output will rotate

through a port in the left steer valve. Simultaneously,

opposite to the direction of travel while the other output

main pressure is admitted to the lower portion of the

rotates with the direction of travel. During normal steer

steer relay valve bore, regulated, and directed through

operation, in second gear (also third and fourth gears)

the steer relay valve to the left geared steer (steering)

geared steer is used. In geared steer, the vehicle turns

clutch.

toward the side with the slowest output. This is done by

(2) The lower portion of the right steer

engaging the steer clutch on the side toward which the

valve directs steer-regulated pressure to the right

turn is made. Refer to paragraph 2-43b, following, for

geared steer (steering) clutch; refer to paragraph 2-41b

description of pivot valve in pivot "water steer" position.

(2) for description of regulating function.

c. Left Steer Value.

(1) During right steer operation, the left

NOTE

steer valve is moved upward. (The steer valves move

The related mechanical functions required

in opposite directions due to an interconnecting pivot

for this travel operation are described in

arm.) The upward movement does not interrupt the

paragraph 2-51b, and illustrated in

apply circuit to the left output. Thus, it remains engaged

figure 2-22.

as the driving clutch.

(2) The lower portion of the valve also

2-43.

Second Gear, Pivot Right Steer Operation

moves upward. This movement allows main-pressure

(fig. 2-11)

oil to enter the right steer signal circuit. Pressure in this

circuit seats the air valve which causes the brake

coolant pump to direct coolant to the right geared steer

clutch (para 2-45c).

2-25