For Rotate Engine Flywheel To Lock Engine At "TDC" To Check High Pressure Fuel Pump Timing. Part Type :Repair Tool. This repair is easier than you may think. Anyone yes, including you, can do it! Application: 4024, 4039, 4045, 4239, 4276, 6359, 6619, 6059, 6068, 6076, 6081, 6090, 6105, 6125 and 6135 Engines.