AST 211 - Automatic Transmission Repair

Theory Hours: 30

Lab Hours: 90

Learning Outcomes:  

  1. Understand and demonstrate general transmission and transaxle operation and diagnosis.

a) Identify and interpret transmission/transaxle concern, differentiate between engine performance and transmission/transaxle concerns; determine necessary action.

b) Research applicable vehicle and service information fluid type, vehicle service history, service precautions, and technical service bulletins.

c) Diagnose fluid loss and condition concerns; determine necessary action. d) Check fluid level in a transmission or a transaxle equipped with a dip-stick.

e) Check fluid level in a transmission or a transaxle not equipped with a dip-stick.

f) Perform pressure tests (including transmissions/transaxles equipped with electronic pressure control); determine necessary action.

g) Diagnose noise and vibration concerns; determine necessary action.

h) Perform stall test; determine necessary action.

i) Perform lock-up converter system tests; determine necessary action.

j) Diagnose transmission/transaxle gear reduction/multiplication concerns using driving, driven, and held member (power flow) principles.

k) Diagnose electronic transmission/transaxle control systems using appropriate test equipment and service information.

l) Diagnose pressure concerns in a transmission using hydraulic principles (Pascal’s Law).

Applies to Automotive Service Technology, A.A.S.  Outcomes A, B, C, D, E, and F.

  2. Understand and demonstrate in-vehicle transmission/transaxle maintenance and repair procedures

a) Inspect, adjust, and replace external manual valve shift linkage, transmission range sensor/switch, and park/neutral position switch.

b) Inspect for leakage; replace external seals, gaskets, and bushings.

c) Inspect, test, adjust, repair, or replace electrical/electronic components and circuits including computers, solenoids, sensors, relays, terminals, connectors, switches, and harnesses.

d) Drain and replace fluid and filter(s).

e) Inspect, replace and align powertrain mounts. 

Applies to Automotive Service Technology, A.A.S.  Outcomes A, B, C, D, E, and F.

  3. Understand and demonstrate out of vehicle transmission and transaxle repair procedures

a) Remove and reinstall transmission/transaxle and torque converter; inspect engine core plugs, rear crankshaft seal, dowel pins, dowel pin holes, and mating surfaces.

b) Inspect, leak test, and flush or replace transmission/transaxle oil cooler, lines, and fittings.

c) Inspect converter flex (drive) plate, converter attaching bolts, converter pilot, converter pump drive surfaces, converter end play, and crankshaft pilot bore.

d) Describe the operational characteristics of a continuously variable transmission (CVT).

e) Describe the operational characteristics of a hybrid vehicle drive train.

f) Disassemble, clean, and inspect transmission/transaxle.

g) Inspect, measure, clean, and replace valve body (includes surfaces, bores, springs, valves, sleeves, retainers, brackets, check valves/balls, screens, spacers, and gaskets).

h) Inspect servo and accumulator bores, pistons, seals, pins, springs, and retainers; determine necessary action.

i) Assemble transmission/transaxle.

j) Inspect, measure, and reseal oil pump assembly and components.

k) Measure transmission/transaxle end play or preload; determine necessary action.

l) Inspect, measure, and replace thrust washers and bearings. 

m) Inspect oil delivery circuits, including seal rings, ring grooves, and sealing surface areas, feed pipes, orifices, and check valves/balls.

n) Inspect bushings; determine necessary action.

o) Inspect and measure planetary gear assembly components; determine necessary action.

p) Inspect case bores, passages, bushings, vents, and mating surfaces; determine necessary action.

q) Diagnose and inspect transaxle drive, link chains, sprockets, gears, bearings, and bushings; perform necessary action.

r) Inspect, measure, repair, adjust or replace transaxle final drive components.

s) Inspect clutch drum, piston, check-balls, springs, retainers, seals, and friction and pressure plates, bands and drums; determine necessary action.

t) Measure clutch pack clearance; determine necessary action.

u) Air test operation of clutch and servo assemblies.

v) Inspect roller and sprag clutch, races, rollers, sprags, springs, cages, retainers; determine necessary action.

Applies to Automotive Service Technology, A.A.S.  Outcomes A, B, C, D, E, and F.