Ford XL2Z-6100-BA Piston And Connecting Rod Assy

The connecting rod bolts/nuts on V6 engines (push rod and SOHC) are "torque-to-yield" design and are NOT reusable; once removed, they must be replaced with new ones. Before installing the piston/connecting rod assemblies, ensure the cylinder walls are clean, the top edge of each cylinder is chamfered, and the crankshaft is in place. Remove the cap from the number one connecting rod, noting the marks made during removal, and clean the bearing surfaces with a lint-free cloth. For the connecting rod bearing oil clearance check, clean the back side of the new upper bearing insert and lay it in place, ensuring the bearing tab fits into the notches. Repeat this for the rod cap without applying lubricant. Position the piston ring gaps at intervals around the piston, lubricate the piston and rings with clean engine oil, and attach a piston ring compressor, leaving the skirt protruding to guide the piston into the cylinder. Rotate the crankshaft until the number one connecting rod journal is at BDC and apply engine oil to the cylinder walls. Insert the piston/connecting rod assembly into the cylinder bore, ensuring the arrow or notches on the piston face the front of the engine, and gently tap the top edge of the ring compressor to ensure contact with the block. Tap the piston with a wooden hammer handle while guiding the connecting rod into place on the crankshaft journal, avoiding any force that could break a ring or the piston. After installation, check the connecting rod bearing oil clearance before permanently bolting the rod cap in place by laying a piece of Plastigage on the journal and installing the rod cap, ensuring the mating marks align. Tighten the nuts or bolts to the specified torque in three steps, using a thin-wall socket to avoid erroneous readings. Remove the nuts and detach the rod cap carefully to avoid disturbing the Plastigage, then compare the width of the crushed Plastigage to the scale to obtain the oil clearance. If the clearance is not as specified, check for dirt or oil between the bearing inserts and the connecting rod or cap, and recheck the journal diameter. After scraping off any Plastigage material, install new rod bolts/nuts on SOHC V6 engines, ensuring the bearing faces are clean and applying a uniform layer of clean moly-base engine assembly lube. Slide the connecting rod back into place, install the rod cap, and tighten the new nuts to the specified torque, ensuring alignment with the recess in the rod. Repeat the procedure for the remaining pistons/connecting rods, keeping the bearing inserts and connecting rods clean, ensuring the correct piston/rod assembly for each cylinder, and lubricating the cylinder walls and bearing faces. After all assemblies are installed, rotate the crankshaft to check for binding, and finally, check the connecting rod end-play, comparing it to the specifications to ensure correctness; if new rods or a new crankshaft were installed, resizing may be necessary if the end play is inadequate.

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

Look for scoring and scuffing on the thrust faces of the skirt, holes in the piston crown, and burned areas at the edge of the crown. These issues indicate overheating or abnormal combustion, which caused excessively high operating temperatures. The cooling and lubrication systems should be checked thoroughly.