v. Shift Valves (fig. 1-37).
Each shift valve consists of a
valve, a calibrated spring, a pin and plug in a bore.
valves are identical and operate basically the same way.
Directing shift signal pressure to the bottom of the valve moves the
valve up against the stop blocking the lower sump port. This allows
clutch feed pressure through the lower land areas and returns clutch
pressure, entering through the upper areas, to the reservoir.
the release of shift pressure, the calibrated spring moves the valve
back down, reversing the operation.
During reverse ranges, reverse pressure applied to the top of the 2-3
and 3-4 shift valves prevents movement of these valves. Since shift
signal pressure is not great enough to overcome both reverse pressure
and spring force, no range shifts occur.
1-2, 2-3, 3-4 Shift Valve.
valve, calibrated spring, pin, and stop in a bore.