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Fig. 550: Overdrive Range, First Gear OVERDRIVE RANGE, SECOND GEAR As vehicle speed increases and other operating conditions are appropriate, the PCM de-energizes 1-2 Shift Solenoid (SS) Valve De-energized (turned OFF) by the PCM, the normally open solenoid opens and signal A fluid 2-3 Shift Solenoid (SS) Valve Energized (ON) as in first gear, the 2-3 shift solenoid valve blocks signal B fluid from exhausting IMPORTANT: The actuator feed limit (AFL) fluid continues to feed the signal A fluid circuit through orifice #25. However, the exhaust port
2008 Chevrolet Silverado 1500 2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
through the solenoid. This maintains signal B fluid pressure at the solenoid end of the 2-3 shift 1-2 Shift Valve Without signal A fluid pressure, spring force moves the valve into the upshift position. D4 fluid is 1-2 Shift Checkball (#8) The 2nd fluid pressure seats the #8 checkball, flows through orifice #16, and fills the 2nd clutch 2-4 Servo Assembly The 2nd clutch fluid pressure moves the #8 checkball, flows through orifice #16 and fills the 2nd 1-2 Accumulator The 2nd clutch fluid pressure also moves the 1-2 accumulator piston against the spring force and Accumulator Valve The accumulator fluid forced out of the 1-2 accumulator is orificed (#30) to the end of the 2-3 Shift Valve Train The signal B fluid pressure from the 2-3 shift solenoid valve holds the valve train in the downshift 3-4 Relay Valve and 4-3 Sequence Valve Spring force holds these valves in the downshift position (first, second and third gear positions).
2008 Chevrolet Silverado 1500 2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
in preparation for a 3-4 upshift. 3-2 Downshift Valve Spring force holds the valve closed, blocking the 2nd fluid and the 2nd clutch fluid. This valve is 3-2 Control Solenoid Valve In second gear, the PCM energizes the normally closed solenoid. This opens the AFL fluid circuit 3-2 Control Valve The 3-2 signal fluid pressure moves the valve against the spring force. This action does not affect 3-4 Shift Valve Signal A fluid pressure exhausts and spring force moves the valve into the downshift position Torque Converter Clutch TCC Solenoid Valve Under normal operating conditions, in Overdrive Range-Second Gear, the PCM keeps the
2008 Chevrolet Silverado 1500 2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Fig. 551: Overdrive Range, Second Gear OVERDRIVE RANGE, THIRD GEAR As vehicle speed increases further and other vehicle operating conditions are appropriate, the 2-3 Shift Solenoid (SS) Valve De-energized (turned OFF) by the PCM, the solenoid opens and actuator feed limit signal B fluid Note: AFL fluid continues to feed signal B fluid to the solenoid through orifice #29. However, 2-3 Shift Valve Train AFL fluid pressure at the 2-3 shift valve moves the valve train toward the solenoid. In the
2008 Chevrolet Silverado 1500 2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Content .. 1177 1178 1179 1180 ..
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