7. Spin on Trans Filters
Jeep 45RFE Internal Allison External
8. Trans Pressure Types
Line Pressure
◦ Pressure developed
by pump and
regulated by main
pressure regulator
valve
◦ 50-60PSI @ Idle
Park
◦ 90-150 PSI
depending on gear
and throttle angle
Governor Pressure
◦ Original pressure
developed by pump
but regulated by
Governor
◦ 0 and Stop and
proportional to speed
Throttle Pressure
◦ Original pressure
developed by pump
but regulated by
Throttle Valve
◦ 0-10PSI Closed
Throttle increased as
throttle angle raises
12. Main Pressure Regulator
Located in Pump Assembly
Spring tension determines initial pressure
regulation
Pressure is “bleed off” to lube, converter,
before returning to sump
Pop off valve prevents pump over
pressure
13. Boost Valve
Increases pressure depending on
conditions
Manual gear boost
◦ Boosts pressure in R and 1st
Balance Valve
◦ Balances line pressure
14. Manual Valve
Directs fluid to
appropriate circuit
◦ Hooked to shift lever
◦ Rooster Comb
provides ‘detents’
◦ Must be correctly
aligned
15. Manual Valve
Directs Main Line Pressure
(Low / Reverse Brake)
(Pressure Regulator)
(Downshift Timing Valve)
P, R, and L-
Ranges
2 and L-Ranges
R Range
Line Pressure (from Oil Pump)
D, 2, and L-
Ranges
P R N D 2 L
15
16. Shift Cable Adjustment
• Push in the lock piece of
the transmission control
cable. Push firmly until the
slider lock is engaged.
• After pushing in the lock
piece, be sure the boot is
not deformed.
Adjustment Mechanism
After
Adjustment
16
17. Shifts using Governor & TV 17
To Second Brake (B2)
Governor Pressure
Line Pressure
(From Manual Valve)
Throttle Pressure
Drain
18. Shift Valves
Acted upon to make shifts
◦ Controlled by TV and Governor
◦ Controlled by shift solenoids in electronic
transmissions
Shift Valves 1st
Shift Valve 2nd
Shift Valve 4th
Shift Valve 4-3 down shift
19. Shift Solenoid Shifting
Shift Solenoid
Shifting
Electronic
transmissions use
shift solenoids to
initiate shifts
Shift solenoids
cause valves to
move and EPC
solenoid regulates
pressure
25. Governor Pressure
Governor pressure used to control shift
timing
At a stop governor pressure low (VENTED)
As speed increases governor pressure
increases (VENT CLOSES)
26. Governor Types
Check Ball
◦ Uses weights
and balls to vent
governor
pressure
Spool Valve
◦ Spool Valve
moves up &
down with
weight
movement
Inspection
29. TV (Throttle Valve) Cables
T.V. Cable attached to
throttle linkage
T.V. controls Line
pressure and will
delay shift under hard
throttle
TV Low at closed
throttle
TV High at WOT
Use as Kick Down for
Forced Down Shift
30. Throttle Valve
Throttle Cam
Transmission Throttle Cable
Line Pressure
(From Pump)
To Shift Valve
To Primary
Regulator Valve
To Secondary
Regulator Valve
Downshift Plug
Spring
Throttle Valve
30
Throttle
Pressure
Line Pressure
Detent Regulator
Pressure
32. Vacuum Modulator TV
Vacuum Modulator
controls shift feel and
timing
Used manifold
vacuum to pull on
diaphragm
High vacuum LOW
pressure
Low vacuum HIGH
pressure
Must have Kick Down
rod or cable for
forced down shifts
33. Check Balls
Can be steel or
rubber
Mark locations prior
to removal
Replace rubber balls
during overhaul
35. Throttle Adjustment
Throttle Adjustment Hydraulic Control Transmission
Too Loose
(angle lower than spec)
• Low throttle (line) pressure
• Early and soft shift
Too Tight
(angle greater than spec)
• High throttle (line) pressure
• Late and hard shift
35
38. Valve Bodies
What to look for
Remove all valves and
springs
Check all bores for
wear…ream if
necessary
Check valve body and
case for flatness
Test all electric
solenoids
Vacuum test valves
39. Valve Body Overhaul/Rebuild
Oversize valve kits
available
Reaming tool comes
with kit
Most rebuilders
include Valve Body
overhaul in cost of
transmission repair
