ATG 345 - GM Automatic Drivetrains

1. Perform proper shop safety procedures.
   1. Apply work area safety skills.
   2. Demonstrate personal safety working habits.
   3. Practice safe tool and equipment usage.
   4. Follow manufacturer’s repair procedures.
   5. Follow manufacture and government warnings and regulations.
2. Automatic Transmission/Transaxle Design and Operation.
   1. Describe basic automatic transmission operation.
   2. Describe the basic laws of physics involved with an automatic transmission operation.
   3. Classify automatic transmissions according to the power train configuration.
   4. Identify the major components in a torque converter and explain their purpose.
   5. Describe the design and operation of the hydraulic controls used in modern transmissions.
   6. Identify the major apply components in an automatic transmission.
   7. Identify the components in a basic planetary gear set and describe their operation.
   8. Describe the purpose and operation of common friction and reaction members.
3. General Drivetrain Diagnosis-Automatic Transmission/Transaxle.
   1. Identify and interpret transmission/transaxle concern, differentiate between engine performance and transmission/transaxle concerns; determine necessary action.
   2. Research applicable vehicle and service information fluid type, vehicle service history, service precautions, and technical service bulletins.
   3. Diagnose fluid loss and condition concerns; determine necessary action.
   4. Check fluid level in a transmission or a transaxle equipped with a dip-stick.
   5. Check fluid level in a transmission or a transaxle not equipped with a dip-stick.
   6. Perform pressure tests (including transmissions/transaxles equipped with electronic pressure control); determine necessary action.
   7. Diagnose noise and vibration concerns; determine necessary action.
   8. Perform stall test; determine necessary action.
   9. Perform lock-up converter system tests; determine necessary action.
   10. Diagnose electronic transmission/transaxle control systems using appropriate test equipment and service information.
   11. Diagnose pressure concerns in a transmission using hydraulic principles (Pascal’s Law).
4. In-Vehicle Transmission/Transaxle Maintenance and Repair.
   1. Inspect, adjust, and replace external manual valve shift linkage, transmission range sensor/switch, and park/neutral position switch.
   2. Inspect for leakage; replace external seals, gaskets, and bushings.
   3. Inspect, test, adjust, repair, or replace electrical/electronic components and circuits including computers, solenoids, sensors, relays, terminals, connectors, switches, and harnesses.
   4. Inspect, replace and align powertrain mounts.
5. Off-Vehicle Automatic Transmission/Transaxle Repair.
   1. Remove and reinstall transmission/transaxle and torque converter; inspect engine core plugs, rear crankshaft seal, dowel pins, dowel pin holes, and mating surfaces
   2. Inspect, leak test, and flush or replace transmission/transaxle oil cooler, lines, and fittings.
   3. Inspect converter flex (drive) plate, converter attaching bolts, converter pilot, converter pump drive surfaces, converter end play, and crankshaft pilot bore.
   4. Disassemble, clean, and inspect transmission/transaxle.
   5. Inspect, measure, clean, and replace valve body (includes surfaces, bores, springs, valves, sleeves, retainers, brackets, check valves/balls, screens, spacers, and gaskets).
   6. Inspect servo and accumulator bores, pistons, seals, pins, springs, and retainers; determine necessary action.
   7. Inspect, measure, and reseal oil pump assembly and components.
   8. Measure transmission/transaxle end play or preload; determine necessary action.
   9. Inspect, measure, and replace thrust washers and bearings.
   10. Inspect oil delivery circuits, including seal rings, ring grooves, and sealing surface areas, feed pipes, orifices, and check valves/balls.
   11. Inspect bushings; determine necessary action.
   12. Inspect and measure planetary gear assembly components; determine necessary action.
   13. Inspect case bores, passages, bushings, vents, and mating surfaces; determine necessary action.
   14. Diagnose and inspect transaxle drive, link chains, sprockets, gears, bearings, and bushings; perform necessary action.
   15. Inspect, measure, repair, adjust or replace transaxle final drive components.
   16. Inspect clutch drum, piston, check-balls, springs, retainers, seals, and friction and pressure plates, bands and drums; determine necessary action.
   17. Measure clutch pack clearance; determine necessary action.
   18. Air test operation of clutch and servo assemblies.
   19. Inspect roller and sprag clutch, races, rollers, sprags, springs, cages, retainers; determine necessary action.
   20. Assemble transmission/transaxle.
   21. Describe the operational characteristics of a continuously variable transmission (CVT).
   22. Describe the operational characteristics of a hybrid vehicle drive train.