Remove the transmission and then take out the 6 bolts that attach the flywheel to the crankshaft flange, noting that the bolt holes are spaced unevenly to ensure the flex plate is installed correctly. Inspect the flex plate for cracks and replace it if necessary. Check the crankshaft flange and flex plate for any burrs or nicks, which should be removed with a mill file. Install the flex plate and torque the bolts to the proper specifications. To check flex plate run-out, mount a dial indicator on the engine block and measure at 3 attaching bosses, ensuring that crankshaft end play is held in one direction; run-out should not exceed .015 inches. If run-out exceeds this limit, tap the high side of the flex plate with a mallet or similar tool to correct it. If the issue persists, remove the flex plate and inspect the flywheel flange for burrs.