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HYDRA-MATIC 6L80 (6 Speed)

6L80 CHECKBALL LOCATION AND FUNCTION
Number 1 Checkball
Number 2 Checkball
Number 3 Checkball
Number 4 Checkball
Number 5 Checkball
Number 6 Checkball
Number 7 Checkball
The number one checkball is located in the upper valve
body, as shown in Figure 25. When the transmission is
operating in Drive 1st, 2nd, 3rd, 4th, 5th or 6th gear, drive
1-6 fluid seats the checkball against the drive braking
passage and enters the 2-6 clutch/1-2-3-4 clutch feed
circuit to apply the 1-2-3-4 clutch.
The number two checkball is located in the upper valve
body, as shown in Figure 25. This shuttle type checkball is
seated against the reverse passage while the transmission
is operating in Park, Neutral and Drive 1st. With the
checkball in this position, shift solenoid 1 fluid enters the
CSV2 enable circuit to the "clutch select valve 2". When
the transmission is operating in Reverse, the checkball
seats against shift solenoid 1 passage to allow reverse fluid
to enter the CSV2 enable circuit and hold the "clutch select
valve 2" in the applied position.
The number three checkball is located in the upper valve
body, as shown in Figure 25. This shuttle type checkball is
seated against the 4-5-6 clutch passage while the
transmission is operating in Park, Reverse, Neutral, Drive
1st, 2nd and 3rd gear. With the checkball in this position,
shift solenoid 2 fluid enters the CSV3 enable circuit to
apply the "clutch select valve 3". When the transmission is
operating in Drive 4th, 5th or 6th gear, the checkball seats
against the shift solenoid 2 passage to allow 4-5-6 clutch
fluid to enter the CSV3 enable circuit and hold the "clutch
select valve 3" in the applied position.
The number four checkball is located in the upper valve
body, as shown in Figure 25. This shuttle type checkball is
seated against the 4-5-6 clutch passage by Pressure
Solenoid 5 fluid, while the transmission is operating in
Park, Reverse, Neutral, Drive 1st, 2nd and 3rd gear. With
the checkball in this position, PS 5 fluid enters the CSV2
latch circuit to hold the "clutch select valve 2" in the
released position. When the transmission is operating in
Drive 4th, 5th or 6th gear, 4-5-6 clutch fluid seats the
checkball against the PS 5 passage to allow 4-5-6 clutch
fluid to enter the CSV2 latch circuit to hold the "clutch
select valve 2" in released the position.
The number five checkball is located in the upper valve
body, as shown in Figure 25. This shuttle type checkball is
seated against the Drive 1-6 passage by 3-5/Reverse Feed
fluid while the transmission is operating in Reverse. With
the checkball in this position, 3-5/Reverse Feed fluid
enters the 3-5/Reverse Supply circuit and is routed to the
number 7 checkball. When the transmission is operating
in Drive 1st, 2nd, 3rd, 4th, 5th or 6th gear, Drive 1-6 fluid
seats the ball against the 3-5/Reverse Feed passage to
allow Drive 1-6 fluid to enter the 3-5/Reverse Supply
circuit.
The number six checkball is located in the upper valve
body, as shown in Figure 25. This "one way orifice
control" type checkball is used to differentiate the flow rate
of fluid between applying and releasing the 1-2-3-4 clutch.
2-6 clutch/1-2-3-4 clutch feed fluid opens the checkball,
while the transmission is operating in Drive 1st, 2nd, 3rd,
4th, 5th or 6th gear. With the ball in this position, 2-6
clutch/1-2-3-4 clutch feed fluid flows freely into the 1-2-3-
4 clutch feed passage. When Park, Reverse or Neutral is
selected after the transmission was operating in Drive,
exhausting 1-2-3-4 clutch feed fluid seats the checkball,
and forces exhausting fluid through orifice number 32,
which allows for a controlled exhaust of the 1-2-3-4 clutch.
The number seven checkball is located in the upper valve
body, as shown in Figure 25. This "one way orifice
control" type checkball is used to differentiate the flow rate
of fluid between applying and releasing the 3-5/Reverse
clutch. 3-5/Reverse Supply fluid pressure seats the
checkball against the 3-5/Reverse Feed passage, while the
transmission is operating in Reverse, Drive 1st, 2nd, 3rd,
4th, 5th or 6th gear. With the checkball in this position, 3-
5/Reverse Supply fluid is forced through orifice number
25 before entering the 3-5/Reverse Feed passage. The
orifice helps control the apply rate of the 3-5/Reverse
clutch when the transmission shifts into Reverse, 3rd or 5th
gear. When Park or Neutral is selected after the
transmission was operating in Drive, or Reverse,
exhausting 3-5/Reverse Feed fluid unseats the checkball.
This allows for a faster exhaust of 3-5/Reverse Feed fluid
and a quick release of the 3-5/Reverse clutch.
AUTOMATIC TRANSMISSION SERVICE GROUP
Technical Service Information
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