807356 Mercruiser SCREW, (.312-18 x 2.680)

start by:a) remove oil pump1. Check the main bearing caps for identification for their location and direction in the block. The caps must be installed in the same location and direction from which they were removed. 2. Remove No. 2 through No. 6 bearing caps (1). Remove thrust bearings from No. 4 main bearing cap. 3. Remove the upper halves of main bearings by the installation of tool (A) in oil hole (2) in the crankshaft. Turn the crankshaft in the direction which will push the end of the bearing with a tab out first.
If the crankshaft is turned in the wrong direction, the tab of the bearing will be pushed between the crankshaft and cylinder block. This can cause damage to either or both.
4. Remove the lower halves of the bearings from the caps.5. Install new bearings in the caps. Put clean engine oil on the bearings.6. Put clean engine oil on the upper halves of the bearings. Install the upper halves of the bearings in the cylinder block with tool (A). Be sure tabs (3) on the back of the bearings fit in the grooves of the caps and cylinder block.7. Check the bearing clearance with wire (B). Put wire (B) on the bearings. Make sure the crankshaft is held up against the upper main bearings before the bearing clearance is checked. The wire will not hold the weight of the crankshaft and give a correct indication. Do not turn crankshaft when lead wire is in position to check clearance. Be sure the main bearing caps are installed so the numbers on the side of the cylinder block are the same as the numbers on the bearing caps, and the arrows (4) on the bearing caps are toward the front of the cylinder block.8. Install the bearing caps for No. 2 through No. 6. Put clean engine oil on the bolts. Install the bolts and tighten bolts, at end with tab first, to a torque of 190 10 lb.ft. (260 14 N m). Turn the bolts an extra 120° 5° first at the end opposite of the tab. Remove the bearing caps for No. 2 through No. 6. Remove wire (B) from the caps. Check the thickness of wire (B) to find the bearing clearance. The bearing clearance must be .0036 to .0073 in. (0.091 to 0.185 mm) with new bearings. The maximum permissible clearance with used bearings is .010 in. (0.254 mm). 9. Put clean engine oil on the threads of the bolts. Install bearing caps (5) for No. 2 through No. 6 main bearings. Install the bolts and tighten the bolts, at the end with the tab first, to a torque of 190 10 lb.ft. (260 14 N m). Put a mark on the bolts and caps. Turn the bolts at opposite end of tab first an extra 120° 5° from the mark.10. Remove the No. 1 and No. 7 main bearing caps. Do Steps 3 through 9 for the No. 1 and No. 7 caps.11. Install the thrust bearings for No. 4 main bearing. Install the thrust bearings with the side that has the identification "BLOCK SIDE" toward the cylinder block. 12. Check the end play of the crankshaft with tool group (C). Be sure the dial indicator is against a machined surface. The end play is controlled by the thrust bearings of No. 4 (center) main. The end play with new bearings must be .006 to .020 in. (0.152 to 0.508 mm). The maximum permissible end play with used bearings is .035 in. (0.89 mm).end by:a) install oil pump