Flexplate

Flexplate (Part 3918160), engineered as the primary rotating connection between a Cummins diesel engine and an automatic transmission torque converter. Flexplates serve the same basic purpose as flywheels in manual transmissions but are specifically designed to flex slightly to accommodate the forces associated with automatic transmissions, helping transfer engine torque smoothly to the drivetrain. It’s commonly used on Cummins B-Series and related engines paired with automatic transmissions. If the flexplate is cracked, warped, or damaged, it can lead to starting problems, vibration, driveline noise, and failure of mating components.