Mercury E3AZ-6303-B Crankshaft Assembly

Crankshaft installation is the first task in engine reassembly, assuming the engine block and crankshaft have been cleaned, inspected, and repaired. Position the engine with the bottom facing up, then remove the main bearing cap bolts and lift out the caps, laying them out in order for correct reinstallation. If old bearing inserts remain, remove them and clean the main bearing surfaces with a lint-free cloth, ensuring they are spotless. Clean the backs of the new main bearing inserts and place one half in each main bearing saddle in the block, with the corresponding half in the main bearing cap, ensuring proper alignment of tabs and oil holes without using lubrication. Install the flanged thrust bearing in the appropriate bearing saddle for the engine type. Clean the bearing faces and crankshaft main bearing journals, checking the oil holes for dirt. Once the crankshaft is clean, carefully position it in the main bearings, and check the main bearing oil clearance using Plastigage, placing it on each crankshaft main bearing journal. Clean the bearing faces in the caps, install them in their respective positions with arrows pointing forward, and tighten the main bearing cap bolts in three steps to the specified torque without rotating the crankshaft. Remove the bolts and lift off the caps, keeping them in order, and compare the crushed Plastigage width to the scale for clearance verification. If the clearance is incorrect, check for dirt or oil interference before considering different bearing inserts. Carefully scrape off any Plastigage material, lift the crankshaft out, clean the bearing faces, and apply a thin layer of moly-base grease or engine assembly lube to each bearing surface, including the thrust faces. Lay the crankshaft back in place, clean the bearing faces in the caps, apply lubricant, and install the caps with arrows pointing forward, tightening bolts finger tight. Tighten all but the thrust bearing cap bolts, pry the crankshaft forward against the thrust surface, and maintain pressure while tightening the thrust bearing cap bolts to the specified torque, then recheck all cap bolt torques. For manual transmission models, install a new pilot bearing in the crankshaft end, rotate the crankshaft by hand to check for binding, and ensure the effort required is not excessive. Finally, check the crankshaft endplay with a feeler gauge or dial indicator, ensuring it is correct if the thrust faces are not worn and new bearings are installed, and install a new one-piece rear main oil seal if equipped. If removed, install the Woodruff key in the front of the crankshaft, filling the keyway chamfer cavity with Loctite 518 or equivalent.

Gently pry or push the crankshaft all the way to the front of the engine.Slip feeler gauges between the crankshaft and the front face of the thrust main bearing to determine the clearance.The thrust bearing is the number 5 bearing saddle on 4.9L engines and in the number three bearing saddle on V6 and V8 engines.

Check the rest of the crankshaft for cracks and other damage. It should be magnafluxed to reveal hidden cracks, a procedure typically handled by an automotive machine shop.

Check crankshaft endplay again and verify that it is correct.

The 4.6L engines have a more complex crankshaft removal and assembly procedure because of the number of bolts used to fasten the main cap to the cylinder block. There are two main cap bolts, two jack screws, and two side bolts on each of the number one through number four main caps.