Mercury 2L2Z-6108-MA Piston And Pin Assembly

You can Select Your Vehicle to check if 2L2Z-6108-MA fits your vehicle.

Check the piston-to-bore clearance by measuring the bore and the piston diameter. Measure the piston across the skirt, at a 90-degree angle to, and in line with, the piston pin. Subtract the piston diameter from the bore diameter to obtain the clearance. If it's greater than specified, the block will have to be rebored and new pistons and rings installed.

Remove the connecting rod cap and bearing insert together. On 4.6L engine connecting rods, the method used to manufacture and machine the rod cap is unique; they "fracture" (break) the cap from the rod to give a perfect match upon reassembly. Don't drop the bearing insert out of the cap.

Clean the back side of the new upper bearing insert, lay it in place in the connecting rod, and make sure the tab on the bearing fits into the recess in the rod. Do not hammer the bearing insert into place and do not lubricate the bearing at this time.

Ensure no dirt or oil was between the bearing inserts and the connecting rod or cap when the clearance was measured, and recheck the journal diameter.

Rotate the crankshaft until the number one connecting rod journal is at BDC (bottom dead center) and apply a coat of engine oil to the cylinder walls.

Remove the bearing insert and push the connecting rod/piston assembly out through the top of the engine. Use a wooden or plastic hammer handle to push on the upper bearing surface in the connecting rod. If resistance is felt, double-check to make sure that all of the ridge was removed from the cylinder.

Measure the piston ring side clearance by laying a new piston ring in each ring groove and slipping a feeler gauge in beside it. Check the clearance at several points around the groove. Use the correct ring for each groove as they are different. If the side clearance is greater than specified, new pistons will have to be used.

Use your fingernail to feel if a ridge has formed at the upper limit of ring travel, which is about 1/4-inch down from the top of each cylinder. If ridges are present due to carbon deposits or cylinder wear, they must be completely removed with a special tool called a ridge reamer before removing the pistons. Follow the manufacturer's instructions with the tool, and do not let it cut into the ring travel area more than 1/32-inch.

The piston/rod assemblies should be cleaned with solvent and dried with compressed air, if available. It is important to ensure that the oil return holes in the back sides of the ring grooves are clear.

Lay a piece of Plastigage on the number one connecting rod journal, install the rod cap, and then remove it to compare the width of the crushed Plastigage to the scale printed on the Plastigage envelope.