18710 Mercruiser CAP, OIL FILLER - SCREW TYPE CAP

The rocker shaft assemblies and push rods do not have to be removed to remove the crankshaft, but bent push rods can be the result if they are not removed.
1. Put the engine in position as shown. The weight of the engine is approximately 4100 kg (9000 lb.). The counterweights do not have to be removed from the crankshaft if the piston and connecting rod assemblies have been removed from the engine. 2. Put identification marks on counterweights (1), and remove them from the crankshaft. 3. Remove bearing caps (2) from the connecting rod, and push the connecting rods away from the crankshaft. Use wire to hold the upper half of the connecting rods away from the crankshaft. 4. Remove the center main bearing cap, and remove two thrust plates (3) from each side of the main bearing.
Typical Example5. Use two of the bolts that hold the flywheel to the crankshaft, and install a bolt in each end of the crankshaft. Fasten a hoist to the crankshaft as shown.6. Remove the remainder of main bearing caps (5), and remove crankshaft (4) from the cylinder block. The weight of the crankshaft is 367 kg (807 lb.). 7. Remove the upper halves of the bearings from the cylinder block and the connecting rod assemblies.8. If necessary, remove bolts (7) to remove gears (6) from each end of the crankshaft.Install Crankshaft
1. If gears (1) were removed from the crankshaft, install the gears on each end of crankshaft (2). The upper halves of the main bearings have an oil hole in the center of the bearing.2. Install the upper halves of main bearings (3) in the block.3. Put the upper halves of rod bearings (4) in position in the connecting rod assemblies. Install the bearings dry when clearance check are made. Put clean engine oil on the bearings for final assembly.If the crankshaft journals and bores for the block and rods were measured at disassembly and found to be within specifications, no further checks are necessary. However, if the serviceman still wants to measure the bearing clearances, Plastigage is recommended. Lead wire, shim stock or use of a dial bore gauge can damage the bearing surface.The serviceman must be very careful to use Plastigage, tool (B) correctly. The following points must be remembered:...Make sure that the backs of the bearings and the bores are clean and dry....Make sure that the bearing locking tabs are properly seated in their slots....The crankshaft must be free of oil where the Plastigage touches it....If the main bearing clearances are checked with the engine upright or on its side, the crankshaft must be supported. Use a jack under an adjacent crankshaft counterweight and hold the crankshaft against the crown of the bearing. If the crankshaft is not supported, the weight of the crankshaft will cause incorrect readings....Put a piece of Plastigage on the crown of the bearing half that is in the cap. Do not allow the Plastigage to extend over the edge of the bearing....Install the bearing cap using the correct torque-turn specifications. Do not use an impact wrench. Be careful not to dislodge the bearing when the cap is installed....Do not turn the crankshaft with the Plastigage installed....Carefully remove the cap but do not remove the Plastigage. Measure the width of the Plastigage while it is in the bearing cap or on the crankshaft journal. Do this by using the correct scale on the package. Record the measurements....Remove the Plastigage before reinstalling the cap.When using Plastigage, the readings can sometimes be unclear. For example, all parts of the Plastigage are not the same width. Measure the major widths to make sure that they are within the specification range. Also, experience has shown that when checking clearances tighter than 0.10 mm (.004 in) the readings may be low by 0.013 to 0.025 mm (.0005 to .0010 in). Out-of-round journals can give faulty readings. Also, journal taper may be indicated when one end of the Plastigage is wider that the other. For complete details concerning measuring bearing clearances, see Engine Bearings And Crankshafts, Form No. SEBD0531.
Typical Example Make sure the work "FRONT" on the end of the crankshaft is toward the front of the cylinder block when the crankshaft is installed.4. Fasten a hoist to crankshaft (2) with two flywheel bolts. Put the crankshaft in position in the cylinder block.5. If necessary, check the main bearing clearances with Plastigage (B) as follows:a. Put the main bearings in position in the main bearing caps. Make sure tab on the back of the bin the tab groove in the main bearing cap. the main bearing cap.b. Put a piece of Plastigage in position on the crown of the crankshaft. The main bearing caps must be installed with the word front and the cast part number toward the front of the cylinder block. Each cap has a number on the bottom surface and must be installed in the same position as the correct number on the side of the block pan rail.c. Put 334-0519 Grease on the thread of the main bearing cap bolts.d. Put the main bearing caps in position, and install the bolts that hold them. Tighten the bolts in the number sequence shown to a torque of 136 14 N m (100 10 lb. ft.). Hand tighten each bolt again in the number sequence 180° 5° of a turn more. Do not turn the crankshaft when the Plastigage is in position.e. Remove the main bearing caps, and measure the Plastigage. The main bearing clearance must be 0.122 to 0.241 mm (.0048 to .0095 in.). 6. Put clean engine oil on thrust plates (9). Install thrust plates (9) on each side of the center main bearing.7. Put the main bearing caps in position, and tighten the bolt as in Step 5d.8. Check the crankshaft end play with tool (A). The end play must be 0.17 to 0.63 mm (.007 to .025 in.). 9. Remove the wire that holds the upper half of the connecting