1. Valvebody Basics

2. Transmission Hydraulic Pressures Mainline Pressure Throttle Pressure Governor Pressure

3. Pressure Regulation • Regulator Valve • Variable Regulated Pressure Building to Max Pressure

4. Pressure Regulator Valve • Bleeds off pressure when maximum pressure is reached. • Exhausts back to sump • If left unregulated can damage components

5. Mainline Pressure(“line pressure”) • Regulated Mainline Pressure is source for all flow • Controlled by pressure regulator • Applies bands and clutches • Feeds Valve Body valves • Applies pressure to one end of pressure regulator valve

6. BOOST PRESSURE • Boosted Mainline Pressure • Boost Valve to raise pressure at low rpm and high engine load • Other pressures are used to modify regulated pressure

7. Throttle Pressure(“modulated pressure”) • Engine Load Sensing • Mechanical • Vacuum • Works against governor pressure • Primary Shift Control signal • Always less or equal to mainline pressure

8. Mechanical Throttle Valve Operation

9. Throttle Valve OperationLow Pressure

10. TV Valve PressureHigher Pressure

11. Vacuum Operated Throttle Valve(vacuum modulated) Page 68c

12. Road Speed signal Opposes TV pressure to control shift points Driven by output shaft Higher speeds = Higher pressure Governor Types Gear Driven Spool Valve Type Check-ball Type Shaft Mounted Valves allow fluid to not bleed off the higher speed you go. Governors stick sometimes and can be cleaned Governor Pressure

13. Centrifugal Governor Operation Spool Valve operated

14. Shaft Mounted Governor

15. Check ball style Governor

16. Shifting and Shift Operations • Manual Valve • Throttle Valve • Downshift Valves • Governor Valve • Spool Valve design • Check-ball design • Shaft Mounted governors

17. Manual Valve Operation • Positioned manually by gear selector lever • Lever moves valve to one of several detent positions • Directs mainline pressure to correct shift valves and apply devices

18. Shift Valve Operation • Shift Valves are: • Flow directing • Switching valves • Spool Type valves • Governor Pressure on one end • Throttle Pressure on other end with spring assist • Blocks or allows fluid flow • Valves must move instantly

19. Shift Valve Operation -When speed is high, governor pressure is higher than throttle pressure. -Allows mainline pressure to pass through and cause a upshift When Vehicle speed low Throttle pressure and spring Pressure are higher than Governor pressure

20. Valve Body(The Brain)

21. Hydraulic CircuitLow Gear • 1 – 2 Shift valve controls upshifts and downshifts between • first and second gears • 2 –3 shift valve controls upshifts and downshifts between second and third gears

22. Hydraulic CircuitSecond Gear

23. Hydraulic CircuitThird Gear