Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Lock-Up Mechanism
The lock-up causes the input shaft (mainshaft) to rotate at the same speed as the engine crankshaft by engaging the torque converter cover with the turbine by the torque converter clutch. Together with the hydraulic control, the PCM optimizes the timing and degree of lock-up. The lock-up mechanism operates in D (during accelerating: 1st, 2nd, 3rd, 4th, 5th, and 6th gears/during decelerating: 2nd, 3rd, 4th, 5th, and 6th gears), S with automatic shift mode (during accelerating: 1st, 2nd, 3rd, 4th, and 5th gears/during decelerating: 2nd, 3rd, 4th, and 5th gears), and S with sequential sportshift mode (during accelerating: 1st, 2nd, 3rd, 4th, 5th, and 6th gears/during decelerating: 2nd, 3rd, 4th, 5th, and 6th gears). The torque converter clutch is in the torque converter. The multi-plate torque converter clutch increases the torque capacity and extends the lock-up area, improving fuel economy.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.