The Lisle Corporation Engine Barring Tool for Cummins, No. 62310, allows the engine crank to be manually adjusted, such as while troubleshooting issues or trying to access torque converter bolts. The tool works on Cummins 3.9L, 8.3L, and B and C series 5.9L and 6.7L diesel engines and is used with a 1/2" square drive.