Lock-Up Mechanism

The lock-up mechanism causes the input shaft (mainshaft) to rotate at the same speed as the engine crankshaft. Pressurized ATF is drained from between the torque converter cover and the torque converter clutch piston through a fluid passage, causing the torque converter clutch piston to be held against the torque converter housing. Together with the hydraulic control, the PCM optimizes the timing and degree of lock-up using shift solenoid valve D and A/T clutch pressure control solenoid valve C. The lock-up mechanism operates in D and S with sequential sportshift mode (2nd, 3rd, 4th, and 5th gears) and S with automatic shift mode (2nd, 3rd, and 4th gears).