Mercury 1L8Z-6375-AA Flywheel Assembly

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Raise the vehicle and support it securely on jackstands, then remove the transaxle. If it's leaking, now would be a very good time to replace the transaxle input shaft seal or torque converter-to-transaxle seal. Remove the pressure plate and clutch disc from manual transaxle equipped vehicles, and check or replace the clutch components. Use a center-punch to make alignment marks on the flywheel/driveplate and crankshaft to ensure correct alignment during reinstallation. Remove the bolts that secure the flywheel/driveplate to the crankshaft; if the crankshaft turns, wedge a screwdriver through the starter opening to jam the flywheel. Carefully remove the flywheel/driveplate 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 check for warpage with a straightedge. Clean and inspect the mating surfaces of the flywheel/driveplate and the crankshaft, replacing the crankshaft rear seal if it is leaking before reinstalling the flywheel/driveplate. Position the flywheel/driveplate 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, then wedge a screwdriver through the starter motor opening to keep the flywheel/driveplate from turning while tightening the bolts in a criss-cross pattern to the specified torque. The remainder of installation follows the reverse of the removal procedure.

To remove the transaxle, first check components like oil seals and replace them if necessary. For manual transaxle models, remove the clutch and inspect or replace the clutch components and release bearing. Make alignment marks on the flywheel and crankshaft to simplify replacement, as the bolt holes are slightly offset. Hold the flywheel/driveplate stationary while unscrewing the bolts; use a transaxle mounting bolt and a wide-bladed screwdriver to prevent turning. Remove each bolt in turn, ensuring new replacements are obtained for reassembly due to the severe stresses they endure. Carefully remove the heavy flywheel, noting that the driveplate for automatic transaxles is lighter. Clean the flywheel to eliminate grease and oil, inspecting for cracks, rivet grooves, burned areas, and score marks, with light scoring removable using emery cloth. Check for cracked and broken ring gear teeth and verify warpage with a straight-edge. Clean the mating surfaces of the flywheel and crankshaft, replacing the oil seal if leaking, especially in high-mileage engines. While the flywheel is off, clean its inboard face and the crankshaft speed/position sensor. For installation, ensure the engine/transaxle adapter plate is in place, align the flywheel/driveplate on the crankshaft using the marks made during removal, and install new bolts, tightening them by hand. Lock the flywheel using the disassembly method, tightening the bolts in a diagonal sequence and gradually increasing to the final torque in two or three stages. The remainder of reassembly follows the reverse of the removal process.

In order to do this, some of the related components such as oil seals will have to be (checked and) replaced or (checked and) if necessary. In manual transaxle vehicles demount the clutch and check and renewal of its components as required. It would be prudent to scratch lines on the flywheel/drive plate and the crankshaft so that when assembling the car the next time it would be easier to align because the bolt holes are slightly offset. To immobilise the flywheel/drive plate, have assistance for turning the screw on the lower end with a screwdriver, or use a piece of angle-iron pressed against the transaxle mounting bolt. Unwind also and slide out each bolt because they are often replaced with new ones whenever using them again since they work under high stress. It is important not to drop the flywheel/drive plate while taking it off, so needs to be done very carefully. For inspection, examine driveplates for any signs of crack as well as elongation of bolt holes and examine ring gear teeth for any signs of damages. Remove grease or oil from the flywheel and examine for cracks and warpage, and check the mating surfaces for leaks it is recommended that the oil seal be replaced. As it is necessary to clean the inboard face of the flywheel and the tip of the sensor, you should do it when the flywheel is off. When installing, make sure the engine/transaxle adapter plate is installed, rotate the flywheel/drive plate and align with the marks made when removing, use new bolts, torque by hand. Secure the flywheel/drive plate as described above for removal, then install new bolts and tighten, in a diagonal pattern, to the specified torque. The balance of the installation works in the sequence if the removal process.

Remember that the flywheel is very heavy and should not be dropped.

Lock the flywheel/driveplate by the method used on disassembly. Working in a diagonal sequence to tighten them evenly, increase to the final amount in three stages, and tighten the new bolts to the specified torque.

Install the new bolts, tightening them by hand. Secure the flywheel into position with the new bolts.