Mercury D1ZZ-6375-A Flywheel Assembly

You can Select Your Vehicle to check if D1ZZ-6375-A fits your vehicle.

Raise the vehicle and support it securely on jackstands, then remove the transmission. If it's leaking, now would be a very good time to replace the front pump seal/O-ring for automatic transmissions. Remove the pressure plate and clutch disc for manual transmission equipped vehicles, and check or replace the clutch components and pilot bearing. Use a center-punch to make alignment marks on the flywheel and crankshaft to ensure correct alignment during reinstallation. Remove the bolts that secure the flywheel to the crankshaft; if the crankshaft turns, wedge a screwdriver through the starter opening to jam the flywheel. Carefully remove the flywheel from the crankshaft, supporting it while removing the last bolt due to its weight. Clean the flywheel to remove grease and oil, inspecting the surface for cracks, rivet grooves, burned areas, and score marks, with light scoring removable using emery cloth. Check for cracked and broken ring gear teeth, laying the flywheel on a flat surface to use a straightedge for checking warpage. Clean and inspect the mating surfaces of the flywheel and crankshaft, replacing the crankshaft rear seal if it is leaking before reinstalling the flywheel. Position the flywheel against the crankshaft, aligning the marks made during removal, noting that some engines have an alignment dowel or staggered bolt holes for correct installation. Apply thread locking compound to the bolt threads before installation, and wedge a screwdriver through the starter motor opening to keep the flywheel from turning as you tighten the bolts to the specified torque. The remainder of installation follows the reverse of the removal procedure.

Remove the transmission by following the appropriate procedures. For a manual shift transmission, take out the clutch pressure plate, cover assembly, and clutch disc. Next, remove the flywheel attaching bolts and take off the flywheel. To install, position the flywheel on the crankshaft flange, coat the threads of the attaching bolts with Loctite or an equivalent, and install the bolts, tightening them in a cross-sequence to the specified torque. For a manual shift transmission, install the clutch disc along with the pressure plate and cover assembly. Reinstall the transmission as per the outlined procedures. For ring gear replacement, applicable only to manual shift transmissions, heat the ring gear with a blow torch on the engine side and carefully knock it off the flywheel without striking the flywheel itself. Heat the new ring gear evenly until it expands enough to fit onto the flywheel, ensuring it is properly seated against the shoulder, and avoid exceeding a temperature of 500 degrees F to maintain the hardness of the ring gear teeth.

Wedge a large screwdriver or prybar between the ring gear teeth and the engine block. It must be positioned so that as the crankshaft moves, the tool bears against the block. Make sure that the tool is not pushing against the oil pan.

Remove the pressure plate and clutch disc. Now is a good time to check/replace the clutch components and pilot bearing.

Use a center-punch to make alignment marks on the flywheel/driveplate and crankshaft.

Inspect the flywheel surface for scoring, heat marks, cracks, and warpage. If any of these conditions exist, the flywheel should be taken to an automotive machine shop to be resurfaced or replaced with a new one. If the flywheel is cracked, it must be replaced with a new one.