Patent 7717244 was granted and assigned to Sonnax on May, 2010 by the United States Patent and Trademark Office.
A replacement torque converter cover designed to withstand mechanical stresses generated in the torque converter lock-up clutch of ALLISON transmissions when such transmissions are utilized with diesel engines and other high-torque truck engines. The original equipment cover includes through-drilled holes for receiving unitary threaded stud pins, which function to attach the cover to the engine crankshaft externally and to drive the lock-up clutch piston internally during operation. The present replacement cover provides a lock-up clutch piston interface wherein such through-drilled holes and unitary threaded stud pins are eliminated, which substantially reduces stress concentration and mechanical fatigue in the replacement cover. In comparison to the unitary threaded stud pins of the original equipment cover, the present replacement cover provides separate threaded stud and drive pin components respectively, which are installed at radially offset positions on opposite sides of a modified radial wall having an increased axial thickness and improved durability.