Chevrolet Light Duty Truck 1973, Service Manual

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l_2 R A N G E - M A N U A L S E C O N D G E A R
Intermediate Clutch - ON
Intermediate Overrun Roller Clutch - LOCKED
Direct Clutch - OFF Low and Reverse Roller Clutch - FREE WHEELING
Forward Clutch - ON Intermediate Overrun Band - ON
Low and Reverse Clutch - OFF
A manual 3-2 downshift can be accomplished by moving the selector lever
from drive to intermediate range (L
2
). Intermediate oil from the manual valve is
then directed to:
1. Intermediate Boost Valve
2. 2-3 Shift Valve
Intermediate oil at the pressure regulator intermediate boost valve will in­
crease minimum line pressure to 80 PSI. Intermediate oil will move the 2-3 shift
valve to the downshifted position regardless of speed. This in turn releases
the direct clutch.
When the manual valve is moved to the intermediate position R.N.D. oil is
exhausted. 1-2 clutch oil acting on the intermediate servo piston then applies the
intermediate overrun band which places the transmission in second gear. This
provides engine braking in the intermediate range by preventing clockwise rota­
tion of the direct clutch drum, sun gear drive shell, and sun gear once the
transmission is in second gear, it cannot upshift to third gear regardless of
speed.
Sum m ary
When the forward, intermediate clutches and intermediate overrun band are
applied, the transmission is in intermediate range—second gear and allows engine
braking. When vehicle slows down to approximately 9 MPH a 2-1 shift will oc­
cur when decreased governor pressure allows the 1-2 shift valve to move and
exhaust the 1-2 clutch.
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