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DRIVE RANGE DETENT DOWNSHIFT (1-2 AND 2-3 SHIFT
VALVES IN SECOND GEAR POSITION)
Intermediate Clutch - ON
Direct Clutch - OFF
Forward Clutch - ON
Low and Reverse Clutch - OFF
Intermediate Overrun Roller Clutch - LOCKED
Low and Roller Clutch - FREE WHEELING
Intermediate Overrun Band - OFF
While operating at speeds below approximately 75 MPH, a forced or detent
3-2 downshift is possible by depressing the accelerator fully. This moves the
detent valve by cable linkage, to its extreme inner position allowing modulator
oil to be routed into the 3-2 part throttle passage and detent regulator oil to be
routed into the modulator shift valve and detent passages. Detent regulated oil
therefore acts on both the 1-2 & 2-3 shift control valves and modulator pressure
also acts on the 2-3 shift control valve through the 3-2 part throttle passage.
Detent regulator oil is also routed to the modulator valve via the detent passage.
Modulator oil, detent regulator oil plus the force of the 2-3 shift control
valve spring will move the 2-3 shift valve to the downshifted position below
approximately 75 MPH shifting the transmission to second gear.
A detent 2-1 or 3-1 downshift can also be accomplished below approxi
mately 40 MPH because detent regulator oil is directed to the 1-2 shift control
valve. This allows detent regulator oil plus the force of the 1-2 shift control valve
spring to move the 1-2 shift valve to the downshifted position placing the trans
mission in first gear.
Detent regulator oil is directed to the modulator valve to prevent modulator
pressure from falling below that of detent regulator at high speeds or at high
NOTE: the 3-2 part throttle downshift can be made below 50 MPH (see insert
of detent valve in part throttle position). At light throttle opening the 3-2 part
throttle passage is exhausted; however, at moderate throttle opening the detent
valve connects modulator pressure to the 3-2 part throttle passage. If modulator
pressure acting on the 3-2 part throttle area of the 2-3 shift control valve plus
the 2-3 shift valve spring is sufficient to move the valve to the downshifted
position, the transmission will be in second gear.
