1973 OPEL GT-R Service Manual

712.641973 OPEL SERVICE MANUALHYDRAULIC OPERATION
‘Irn

a.Operation of Controls in Neutral Engine Running
Reverse Clutch ReleasedThird Clutch Released
Second Clutch ReleasedSprag LockedLow Band Released
Whenever the engine is running with the selector lever in Neutral, oil is pulled from the sump into the oil pump and is dispensed from the pump under preure.
The pressurized line oil if directed
to the priming valve which bleeds off the air. Line oil is directed to the vacuum modulator YBIYB, to the prexwre regulator valveand
to the manual veIve. The converter is fed through the pressure regulator MIYB. the return oil from the converter being directed through the coalerand back
into the transmisGon’s lubricating system.
Line oil directed
to the vacuum modulator valve becomes regulated to modulator oiland acts on the pressure regulator boosI YBCB. the IDW speed downshift timing
valve. the 1 2 accumulator MIYB. and the detent valve. The modulator oil passes through the detent valve to act 00 the I 2 shift control give. the 3 2 control
valve and the 2 3 shift control valve. Line oil pasres through the manual v&e. and is regulated et the detent preaure regulator valve before being directed to the
Reverseand Low control delve.Summary
The converter is filled. the clutches and
IDW band are released.The transmission is in Neutral.

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1973 OPEL SERVICE MANUAL

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c. Operation of Controls in Drive Range Second Gear
Reverse Clutch
ReleasedThird Clutch Released
Second Clutch AppliedLow Band Applied
Sprag Over Running
As the vehicle increws speed. the govwnor
allow more drive oil 10 pass through, and this increased pressure, acting on the end of the 1 2 shift
vahre. overcomes the I 2 shift valve spring pressure and allovn drive oil 10 pasr through the valve to feed the second clutch oil parsages.Second clutch oil passes through the second clutch orifice control valve, seating the ball and is metered to the second clutch piRon
to begin to apply
the second clutch, whileportion of the oil is directed
10 the accumulator. As the upper portion of the accumulator fills with second clutch oil. itovercomes the leer prewre of 1 2 accumulator oil and spring at the bottom of the accumulator piston. forcing the piston downward. The upper
portion of the accumulator is now filled, allowing full oil preaure
to the second clutch piEton far the final apply. The accumulator, therefore, acts as a
reservoir
10 produce a damping effect for a smooth second clutch apply and the 1 2 shift.
Second clutch oil from the 1 2 shift
valve is simultaneously directed to the 2 3 shift valve to be used as the oil source for the 2 3 shift.
Summary
The second clutch is on. the band is on, the transmission is in drive range
i second gear.

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d. Operation of Controls in Drive Range Third Geat
Reverse Clutch ReleasedThird Clutch-Applied
Second Clutchs AppliedLow Band Released
Sprag Locked
As vehicle speed increases. the governor allows more oil to pass through to act against the wring
at the 2 3 shift valve. This allows the second clutch oil at
the 2 3 shift valve
10 be released and pan through the valve as third clutch oil, directed tothe third clutch piston to apply third clutch. At the same time,
third clutch oil is directed
to the 3 2 control valve. acting against the spring and modulator oil. cutting off modulator oil pressure to the 2. 3 shift controlyalve. Third control oil also is directed to the Reverse and Law control valve and pasts through thevalveasservo release oil to the lowspeed downshift
timing valve. The low speed downshih timing valve is held
open against the spring by increased modulator oil pressure. The oil passes through the valve and
is directed
to the top of the low band sewo. to act with the servo piston spring and force the sel~o piston downward. releasing the low band.
The second clutch is on, the third clutch is on, the band is released. The transmikn is in drive range third gear