Mercury 8L2Z-6108-E Piston And Pin Assembly

Before the piston and connecting rod assemblies can be removed, the cylinder heads, oil pan and oil pump have to be taken off on 5.0L engines depending on the type of engine that will be overhauled. First, look for any sharp edges at the extremes of ring travel, the ring travel and those should be gotten rid of by use of a reamer before you attempt to remove the piston and connecting rod assemblies since tearing of the pistons may occur. After that level off the ridges turn the engine upside down in such a way that the crankshaft is on the top. Measure the endplay of the connecting rods with the help of dial indicator or feeler gauges; if the endplay of the rods is more than the service limit specified, then it may be necessary to fit new connecting rods. Label the connecting rods and caps to distinguish them from one another; alternatively, back off the cap nuts the last half turn before they are ready to come off. Withdraw the connecting rod cap together with the bearing insert-be careful not to let the bearing insert fall. When the connecting rod has studs with nuts, it is advisable to cover the crankshaft journal and cylinder wall with plastic or rubber hose in order to remove the piston. Force the complete connecting rod and piston assembly out through the top of the engine by means of a wooden or plastic hammer handle respectively , and make sure that all ridges are got rid of. Proceed in the same manner for each of the other cylinders which are also present in the apparatus. Upon removal, align and replace the connecting rod caps and bearing inserts back into the rightful rods fastening the cap nuts loosely so as not to harm the bearing of the rod . As it will cause difficulty in reassembly of the pistons with the connecting rods retain the two as a single unit.

After the cylinder ridges have been removed, turn the engine so the crankshaft is facing up.

Remove the cap from the end of the number one connecting rod, remove the original bearing inserts, and wipe the bearing surfaces of the connecting rod and cap with a clean, lint-free cloth. They must be kept spotlessly clean.