Page 43 - Hydra-matic 6 Speed RWD Technician's Guide (October 2005)

HYDRAULIC CONTROL COMPONENTS

VALVES LOCATED IN THE UPPER CONTROL VALVE BODY

Actuator Feed Limit Valve (325): 3-5 Reverse Clutch Boost Valve (329):
The pressure control solenoids and the shift solenoids cannot PCS 3-5 reverse clutch fluid pressure acts on a differential area
support more than a given fluid pressure. In order not to over- moving the 3-5 clutch boost valve against the 3-5 clutch boost
pressurize the solenoids, the actuator feed limit valve regulates valve spring (330). 3-5 reverse clutch fluid passes through the
line fluid pressure into the actuator feed limit fluid circuit. valve and enters the 3-5 reverse clutch feedback circuit. As
When pressure exceeds a given pressure, the valve limits flow PCS 3-5 reverse clutch fluid pressure is increased to a given
into the circuit, keeping pressure below the given value. Force value, the 3-5 reverse clutch boost valve opens the 3-5 reverse
from the actuator feed limit valve spring (324) and orificed clutch feedback circuit to exhaust. This results in the 3-5 reverse
actuator feed limit fluid pressure acting on the end of the valve clutch regulator valve moving to the full feed position sending
regulate line pressure as it passes through the valve and enters full 3-5 clutch reverse feed pressure (full line pressure) to the
the feed limit circuit. Actuator feed limit pressures will nor- clutch.
mally equal line pressure when line pressure is below the cali-
brated limiting values.
3-5 Reverse Clutch Regulator Valve (336):
• Stuck in the released position would cause high actuator Responds to orificed PCS 3-5 reverse clutch fluid pressure act-
feed fluid pressure resulting in harsh shift conditions and ing on one end of the valve and it is biased by 3-5 reverse clutch
damaged components. spring force and orificed 3-5 reverse clutch feedback fluid pres-
• Stuck in the applied position would cause low actuator sure on the other end of the valve. When applied, it regulates
feed fluid pressure resulting in no/slipping shift orificed 3-5 reverse clutch feed fluid pressure as it passes through
conditions. the valve and enters the 3-5 reverse clutch fluid circuit during
Drive 3rd, 5th and reverse gear ranges. When in the released
CBR1/C456 Clutch Regulator Valve (327): position, it allows 3-5 reverse clutch fluid to exhaust through
The CBR1/C456 clutch regulator valve responds to orificed the valve into the exhaust backfill fluid circuit. Also, when in
PCS CBR1/456 clutch fluid pressure acting on one end of the the released or regulating position, actuator feed limit fluid passes
valve and biased by spring force and CBR1 feedback fluid through the valve and enters the PS1 fluid circuit. PS1 fluid is
pressure on the other end of the valve. When applied it regu- then routed to pressure switch 1 and opens the switch.
lates orificed line pressure as it passes through the valve and
enters the CBR1/456 clutch feed fluid circuit during Park, Re-
verse, Neutral, 1st (Engine Braking), 4th, 5th and 6th gear 1-2-3-4 Clutch Regulator Valve (337):
ranges. In Drive 1st, 2nd and 3rd gear ranges, the valve is in Responds to orificed PCS 1-2-3-4 clutch fluid pressure acting
the released position to allow CBR1 feedback fluid and CBR1/ on one end of the valve and it is biased by 1-2-3-4 clutch
456 clutch fluid to be open to exhaust backfill. Also, when in regulator valve spring (326) force and orificed 1-2-3-4 clutch
the released or regulating position, drive 1-6 fluid passes through feedback fluid pressure on the other end of the valve. When
the valve and enters the PS5 fluid circuit. PS5 fluid is then applied, it regulates orificed 1-2-3-4 clutch feed fluid pressure
routed to pressure switch 5 and opens the switch. as it passes through the valve and enters the 1-2-3-4 clutch fluid
circuit during Drive 1st (engine braking), 1st, 2nd, 3rd and 4th
gear ranges. When in the released position, it allows 1-2-3-4
4-5-6 Boost Valve (329): clutch fluid to exhaust through the valve into the exhaust back-
PCS CBR1/456 clutch fluid pressure acts on a differential area fill fluid circuit. Also, when in the released or regulating posi-
moving the 4-5-6 clutch boost valve against the 4-5-6 clutch tion, 1-2-3-4 clutch feed fluid passes through the valve and
boost valve spring (330). CBR1/456 clutch feed fluid passes enters the PS4 fluid circuit. PS4 fluid is then routed to pressure
through the valve and enters the CBR1 feedback circuit. As switch 4 and opens the switch.
PCS CBR1/456 clutch fluid pressure is increased to a given
value, the 4-5-6 clutch boost valve opens the CBR1 feedback
circuit to exhaust. This results in the CBR1/456 clutch regulator 1-2-3-4 Clutch Shuttle Valve (338):
valve moving to the full feed position sending full line pressure Responds to orificed 1-2-3-4 clutch default fluid pressure acting
to the clutch. on the end of the valve to force the 1-2-3-4 clutch regulator
valve to move to the applied position against spring force and 1-
2-3-4 clutch feedback fluid pressure. In the event of an electri-
2-6 Clutch Regulator Valve (334) and cal, TCM or other failure which puts the transmission in default
2-6 Clutch Regulator Gain Valve (335): mode, orificed 1-2-3-4 clutch default fluid pressure would move
Responds to orificed PCS 2-6 clutch fluid pressure acting on the shuttle valve and 1-2-3-4 clutch regulator valve to the apply
the 2-6 clutch regulator valve gain valve at one end of the valve position. If this event occurs, the transmission would operate in
and it is biased by spring force and orificed 2-6 clutch fluid Drive 3rd or 5th gear, dependent on when the failure occurs.
pressure on the other end of the valve. It regulates orificed 2-6 The transmission will also operate in Park, Reverse and Neutral.
clutch/1234 clutch feed fluid pressure as it passes through the
valve and enters the 2-6 clutch fluid circuit during Drive 2nd
and 6th gear ranges. In 6th gear, 456 clutch fluid pressure acts 1-2-3-4 Clutch Boost Valve (329):
on the 2-6 clutch regulator gain valve to lower the PCS pressure PCS 1-2-3-4 clutch fluid pressure acts on a differential area
to the valve output pressure ratio. This allows for better control moving the 1-2-3-4 clutch boost valve against the 1-2-3-4
of the 5-6 shift. When in the released position it allows 2-6 clutch boost valve spring (330). 1-2-3-4 clutch fluid passes
clutch fluid to exhaust through the valve into the exhaust back- through the valve and enters the 1-2-3-4 clutch feedback circuit.
fill fluid circuit. Also, when in the released or regulating posi- As PCS 1-2-3-4 clutch fluid pressure is increased to a given
tion, 2-6 clutch/1234 clutch feed fluid passes through the valve value, the 1-2-3-4 clutch boost valve opens the 1-2-3-4 clutch
and enters the PS3 fluid circuit. PS3 fluid is then routed to feedback circuit to exhaust. This results in the 1-2-3-4 clutch
pressure switch 3 and opens the switch. regulator valve moving to the full feed position, sending full 1-
2-3-4 clutch feed pressure (full line pressure) to the clutch.

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