Advanced Auto Tech Worksheet Name Auto Trans & Transaxle Chapter 40 Pages 1173 1215 107 Points Due Date 1. Automatic transmissions are operated by hydraulics as well as electronics to select according to engine speed, powertrain load, vehicle speed, and other factors. 2. The number of forward gears offered in current vehicle ranges from to and there are also continuously variable designs (CVT) with no fixed ratio. All offer at least one overdrive ratio for mpg. 3. The is a one piece, welded unit, fluid coupling between the engine & trans that multiplies the twisting motion of the crankshaft & passes it through to the transmission. 4. The T/C is connected to the crankshaft flange through a metal that holds the starter ring gear. A flywheel is not needed because the T/C has enough mass to provide inertia. 5. A standard torque converter consists of 3 basic parts:,, &. 6. The impeller is the input or member of the T/C and it always spins at engine rpm. (T/C pump) 7. The turbine is the output or member Of the T/C and is splined to the trans input shaft. 8. The stator is the member or torque multiplier of the T/C & operates on a 1 way clutch. 9. The torque converter is often used to drive the front pump of the transmission. 10. There is no direct connection between the impeller & turbine & they never achieve the same speed. They only come close during the coupling point at highest rotary flow. 11. flow is ATF flow around the circumference of the T/C. flow is ATF flow occurring from the impeller to the turbine & back to the impeller. (draw a vortex here) 12. Highest vortex flow takes place at the highest multiplication, when the speed difference between the impeller and turbine is the greatest. Highest rotary flow is at the coupling stage. 13. The contains a one way clutch that is splined to the stator support on the front pump. 14. The sprag or roller clutch in the stator is generally known as an clutch. 15. As a vehicle begins to move, the stator 1 way clutch is. If it were not locked, the vehicle would have a severe loss of power. So a T/C can be the cause of doggy acceleration. 16. The stator one way roller or sprag clutch when the impeller & turbine reach the coupling (nearly the same speed) stage. 17. A stator roller clutch that is at all times (couldn t freewheel) would limit top end. 18. A torque converter eliminates the 10% slippage between impeller & turbine @ coupling.
19. ATF to apply the lockup clutch piston in the T/C is fed through a hollow (input) shaft. 20. The controls T/C lockup clutch (TCC) operation by switching solenoids that control ATF flow. 21. A gearset has a sun gear, a carrier with planetary pinions & an internal ring gear. 22. The gear is located in the center of the planetary gearset. It can be either spur or helical. 23. Planetary gears rotate on needle bearings & are held in a framework. 24. The or internal ring gear surrounds the whole gearset adding strength to it. 25. Power through a planetary gearset depends on which members are held, driven, or at rest. The best advice to remembering this is to keep you eye on the planetary carrier. 26. If the carrier is driven, (output) the result is a in speed & a gain in torque. 27. If the carrier drives, (input) the result is an in speed & a loss of torque. 28. If the carrier is held, the result is. 29. If two members of the planetary gearset are locked or held together a 1:1 drive results. 30. When no member of the planetary gearset is held, a condition exists. 31. A planetary gearset is simply two planetary gearsets connected together. 32. A compound planetary gearset shares a common sun gear between the front & rear or input & reaction gearsets. The most commonly used compound planetary gearset. 33. A compound planetary gearset shares a common ring gear between the front & rear or input & reaction gearsets. 3 long pinions & 3 short pinions are used in the carrier. 34. planetary gearsets are those located in series, but not sharing a component like the Simpson & the Ravigneaux do. (front carrier locked to rear ring & front ring locked to rear carrier)
35. The system connects a simple planetary set on to a Ravigneaux set to achieve 6, 7, or 8 forward speeds! Electronic controls have made this intense design practical for use. 36. Honda has a based transaxle that is automatically shifted with gears as in a manual transaxle, but they are electro hydraulically put into action. 37. The CVT or has no fixed forward speeds and relies on a steel belt that changes effective diameter to achieve variable drive ratios. 38. The Nissan CVT is a design based on discs & rollers. 39. vehicles use planetary gear based CVTs. 40. Transmissions use &, wet, multi disc and one way sprag or roller clutches to hold planetary gearset members and achieve their gear ratios. 41. A band (also called brake band) can wrap around the outside diameter of clutch drums to it from rotating in either direction. Bands apply with hydraulic servo pressure & lock to the case. 42. Bands may be or flexible and may also be either or double wrap types. 43. ATF fluid pressure is used to a servo. With pressure released, springs un apply servos. 44. A servo that uses fluid pressure to both apply & un apply it is called a servo. 45. Overrunning (one way) clutches have the advantage of engagement. 46. Multiple disc clutch plates are applied by fluid pressure acting on clutch. These clutch plates are released or unapplied by pressure when fluid pressure is released. 47. A clutch pack consists of clutch plates or discs that are externally splined, plates which are lined on both surfaces & internally splined, and a very thick, top pressure plate. 48. Clutch plates must be perfectly. Friction plates are lined w/ paper fibers, graphite & ceramics. 49. bearings, thrust washers made of synthetic materials, and steel thrust washers coated with low friction materials are used to control axial play inside of automatic transmissions. 50. Many different types & sizes of are used to hold assemblies together. 51. gaskets are used to direct fluid flow or seal off passages. They never get sealer on them! 52. gaskets are used on irregular surfaces like the oil pan. Sealer is occasionally used on them. 53. A seal is used between two non moving parts. A seal is used between two parts that move in relation to each other. 54. A seal is designed to prevent all fluid leakage between parts. A non positive seal is designed to allow a controlled amount of leakage, typically to allow lubrication.
55. 3 major types of rubber seals used are, seals, & seals. 56. 3 types of metal seals used are end, end, and end seals. 57. One piece seals need special installation tools but scarf cut seals can easily be replaced. 58. The last set of gears in a drive train is called the. Transaxles have the final drive gears (differential) located inside of the case. 59. Pascsal s basic law of hydraulics states that exerted on a confined liquid is transmitted undiminished and equally in all directions with equal force on all areas. F = P x A 60. Since fluids cannot be, they work well to increase force when conducting fluid pressure through a circuit operating a piston with a larger surface area from one with a smaller area. 61. The ATF circulating in the transmission the parts, lubricates parts, cleans parts and flows under pressure through passages causing valve movement, and the application of clutches & servos. 62. The main ATF reservoir is the. Fluid level is typically checked with a. 63. All fluid reservoirs must have an air to allow atmospheric pressure to act on the fluid. 64. Excessive heat (above 175 F) causes ATF to break down so are essential components. 65. The is responsible for control & distribution of pressurized fluid. 67. ATF flows through precisely machined and fluid passages (worm passages) in the cast iron or aluminum valve bodies. 68. plates & transfer plates between the valve body & case with seal off passages. 69. Check ball valves, poppet & spool valves are used to,, direct & regulate fluid flow. 70. Each spool valve has a valley that forms a fluid pressure chamber, used to cover or uncover fluid flow ports, and a reaction area on which fluid & spring pressure acts. 71. The pressure source in the transmission is the oil while the contains the control valving to regulate & direct the pressure & flow of fluid to servos & clutches. 72. Pump pressure (called main line pressure) is a variable depending upon engine and the operation of a main pressure regulator valve. 73. 3 basic pump designs in use are the,, and types. 74. A pressure valve maintains proper fluid pressure in the transmission. 75. Many transmissions now have pressure control solenoids to regulate pressure. (EPC)
76. The is an output shaft mounted, speed sensitive device that develops a pressure that gets directed against a shift valve to demand an upshift. 77. Both the vacuum & the valve are load sensitive devices used to increase main line so that clutches & bands can be held tighter while demanding uphift. 78. The valve is the only spool valve that gets controlled directly by the driver through the gear selector linkage. PRNDL 79. It can be said that the demands downshifts & allows upshifts. (based on load MAP) 80. It can be said that the demands upshifts & allows downshifts. (based on speed VSS) 81. A circuit provides a downshift (lower gear) when the driver requires more power. 82. Shift feel is controlled by the at which each reaction member is applied or released, the at which each is pressurized or exhausted, & the of the apply & release. 83. slow down application rates without decreasing the holding force of the device. 84. Some transmissions use restrictive instead of accumulators in line to a servo or clutch piston to allow for gradual increase of fluid flow and smooth engagement of a band or clutch. 85. Shift is different than shift feel. Shift timing is determined by throttle & governor pressures acting on shift valves. 86. Shift can be used to time the shifts and to also provide shift feel through pulse width modulation of fluid into controlling members. 87. Hydraulic circuit and clutch & band application charts are used to diagnose improper operation prior to service.