Chevrolet Light Duty Truck 1973, Service Manual

Page: 659 / 979

D R I V E R A N G E - I N T E R M E D I A T E ( S E C O N D G E A R )
Intermediate Clutch - ON Intermediate Overrun Roller Clutch - LOCKED
Direct Clutch - OFF
Low and Roller Clutch - FREE WHEELING
Forward Clutch - ON
Intermediate Overrun Band - OFF
Low and Reverse Clutch - OFF
As both vehicle speed and governor pressure increase, the force of governor
pressure (46 PSI @ W.O.T.) acting on the 1-2 shift valve overcome the force of
the 1-2 shift valve spring and modulator oil regulated by the modulator valve.
This allows the 1-2 shift valve to move to the upshifted position which directs
drive oil to apply the intermediate clutch. Oil in this passage is called (1-2)
clutch oil.
Intermediate (1-2) clutch oil from the 1-2 shift valve is directed to:
1. Intermediate Clutch
2. 2-3 Accumulator
3. 1-2 Accumulator
Basic C o n tro l
Intermediate clutch oil flows from the 1-2 shift valve through the 2-3 accu­
mulator. And then to the 1-2 accumulator which cushions intermediate clutch
application. The 1-2 accumulator has clutch apply pressure and a calibration
spring acting on one side with line pressure on the other side.
Sum m ary
The forward and intermediate clutch are applied. The transmission is in drive
range 2nd gear. When in drive range the full throttle 1-2 upshift will occur at
approximately 50 MPH and minimum throttle 1-2 upshift will occur at approxi­
mately 12 MPH.
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