Kickdown Valve; Kickdown Limit Valve - Jeep 200 Cherokee Service Manual

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DESCRIPTION AND OPERATION (Continued)
1 – GOVERNOR PLUG
2 – 2-3 SHIFT VALVE
3 – KICKDOWN VALVE
4 – THROTTLE VALVE
5 – MAXIMUM THROTTLE PRESSURE

KICKDOWN VALVE

When the throttle valve is as far over to the left as
it can go, the maximum line pressure possible will
enter the throttle pressure circuit. In this case, throt-
tle pressure will equal line pressure. With the kick-
down valve (Fig. 24) pushed into the bore as far as it
will go, fluid initially flows through the annular
groove of the 2–3 shift valve (which will be in the
direct drive position to the right).
After passing the annular groove, the fluid is
routed to the spring end of the 2–3 shift valve. Fluid
pressure reacting on the area of land #1 overcomes
governor pressure, downshifting the 2–3 shift valve
into the kickdown, or second gear stage of operation.
The valve is held in the kickdown position by throttle
pressure routed from a seated check ball (#2). Again,
if vehicle speed is low enough, throttle pressure will
also push the 1–2 shift valve left to seat its governor
plug, and downshift to drive breakaway.
AUTOMATIC TRANSMISSION—30RH
Fig. 24 Kickdown Valve
6 – THROTTLE VALVE
7 – MANUAL VALVE
8 – 1-2 SHIFT VALVE
9 – GOVERNOR PLUG

KICKDOWN LIMIT VALVE

The purpose of the limit valve is to prevent a 3–2
downshift at higher speeds when a part–throttle
downshift is not desirable. At these higher speeds
only a full throttle 3–2 downshift will occur. At low
road speeds (Fig. 25) the limit valve does not come
into play and does not affect the downshifts. As the
vehicle's speed increases (Fig. 26), the governor pres-
sure also increases. The increased governor pressure
acts on the reaction area of the bottom land of the
limit valve overcoming the spring force trying to
push the valve toward the bottom of its bore. This
pushes the valve upward against the spring and bot-
toms the valve against the top of the housing. With
the valve bottomed against the housing, the throttle
pressure supplied to the valve will be closed off by
the bottom land of the limit valve. When the supply
of throttle pressure has been shut off, the 3–2 part
throttle downshift plug becomes inoperative, because
no pressure is acting on its reaction area.
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