pumps

1. Pump
Pressure Regulation
and
Control Valve Bodies

2. Pump Types
 Gear & Rotor
 Crescent/Internal
& External
 Vane

3. SCREEN FILTERS
 Screen type has
very fine mesh
screen
 Can be cleaned
 Screen can tear
when plugged due
to pump pulses

4. Surface Filter
 Collect debris on
surface of filter
 Can be pleated as
well
 Longer life than
screen due to
increased surface
area

5. PLUGGED FILTERS
ATMOSPHERIC
PRESSURE
15 psi
12 PSI PUMP
SUCTION

6. DEPTH FILTERS (FELT)
•MORE EXPENSIVE
•LASTLIFETIME
•SPLITCASE
TRANSMISSIONS

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

9. Static & Dynamic Pressures
Static Pressure Dynamic Pressure
SRV LMod

10. Pump & Regulation

11. Spool valve terminology
Face
Land
Valley

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

20. Downshift/Kick-Down Plug
1-2 Shift Valve 2-3 Shift Valve 3-4 Shift
Valve
Detent
Regulator
Pressure
Downshift
Plug
Throttle CamTransmission
Throttle
Cable
20

21. GOVERNOR THERORY
25mph

22. GOVERNOR THERORY
35mph

23. GOVERNOR THERORY
48mph

24. GOVERNOR THERORY
60mph

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

27. Governor Valve
Drain
Governor
Pressure
Line Pressure
Outer Weight
Inner Weight
Stopper
Governor Driven Gear
Governor
Valve
Differential Drive
Portion
27

28. Governor Pressure
Drain
Governor
Pressure
Line Pressure
Low Speed Middle and High Speed
Outer Weight
Inner Weight
Stopper
Drain
Governor
Pressure
Line Pressure
28

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

31. TV Cable Adjustment
 TV cables must be
adjusted to proper
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

34. Check Ball
Line Pressure
(from shift
valve)
To Clutch
Slows apply. ↑
Speeds release. ↓
34

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

36. Valve Bodies

37. Valve Body
Components
• Valve body
• Separator plate
• Separator plate gasket
• Shift solenoids
• TFT (trans fluid temp)sensor

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

40. Valve Body Rebuild Kits

41. New Valve Bodies
 Very costly
 Approximately $300-$1500
 Usually replaced under warranty due to
high cost