0317488 JOHNSON ORIFICE PLUG (72C)

1. Remove the carbon from the top inside surface of the cylinder liners.2. Turn the crankshaft until two pistons are at bottom center.3. Remove bearing caps (1) from the two connecting rods. Put pieces of rubber hose or tape on the threads of the connecting rod bolts as protection for the crankshaft. Put identification on each bearing cap so it will be installed on the correct connecting rod. 4. Push the pistons up until the piston rings are clear of the cylinder liner. Remove pistons (2).
Do not turn the crankshaft while any of the connecting rods are in the engine without the caps installed. Do not damage the cooling tubes when the pistons are removed.
5. Do Steps 1 through 4 for the remainder of the pistons.Install Pistons & Connecting Rod Assemblies
1. Be sure that the pistons are installed with flat surfaces (2) of the connecting rods caps toward each other and the chamfered sides (1) toward the crankshaft. 2. Put clean engine oil on the piston rings and cylinder liners.3. Put two pistons in position opposite of each other in the correct bore of the block. Install pistons (3) with Tool (A). For more detail about checking bearing clearances and installation of connecting rod bearings, see the topic, "Remove & Install Connecting Rod Bearings" in this Manual.4. Check the bearing clearances with Plastigage.5. Put clean engine oil on the bolts. Install the connecting rod caps and nuts finger tight. Make sure the flat side of each cap is toward the other cap. The chamfered side must be toward the crankshaft. Tighten each nut to a torque of 82 8 N m (60 6 lb ft). Put a mark across the nuts and bolts. Tighten each nut an additional 120 5 degrees (1/3 of a turn).
Do not use an impact wrench to tighten the nuts the additional 120 degrees (1/3 of a turn).
6. Check the side clearance between two connecting rods on the same crankshaft journal. Clearance must be 0.28 to 0.84 mm (.011 to .033 in) for new rods.7. Do Steps 1 through 6 for the remainder of the pistons.End By:a. install piston cooling tubesb. install oil pumpc. install cylinder headsDisassemble & Assemble Piston & Connecting Rod Assemblies
Start By:a. remove pistons and connecting rod assemblies 1. Remove bearings (3) from the connecting rod and connecting rod cap.2. Remove retainer ring (1) with Tool (A) (no special Tool necessary).3. Remove pin (2) and connecting rod (4) from the piston. 4. Remove piston rings (5) from the piston with Tool (B). Clean the piston ring grooves on the pistons with an acceptable ring groove cleaning tool. See Use Of Piston Pin Bearing Removal And Installation Tools, Special Instructions, SMHS7295.5. Heat connecting rod (4) in an oven to a temperature of 177° to 260°C (350° to 500°F). Do not use a direct flame to heat the connecting rod. 6. Put connecting rod (4) in position on the base plate of Tool (C). Put a new rod pin bearing (6) on the adapter part of Tool (C). The old bearing is pushed out by Tool (C) as the new bearing is installed.7. Use Tool (C) to push the new bearing into the connecting rod until the push adapter of Tool (C) makes full contact with the connecting rod surface.8. Use a pin boring machine to make the rod pin bearing the correct size. The bore in the new rod pin bearing must be 50.830 0.008 mm (2.0012 .0003 in).9. Check the clearance between the ends of the piston rings. See the topic "Pistons & Rings" in Specifications Manual, SENR5516.10. Install the oil ring spring in the oil ring groove of the piston. The oil ring is to be installed over the spring with the oil ring end gap 180 degrees from the oil ring spring joint. 11. Install the oil ring on the piston with Tool (B).12. Install the second (intermediate) piston ring with the side that has the identification "UP-2" toward the top of the piston. Use Tool (B) to install the ring.13. Install the first (top) piston ring with the side that has the identification "UP-1" toward the top of the piston. Use Tool (B) to install the ring. After the installation of all three piston rings, put the piston rings in position so the end gaps are 120 degrees apart.
The rod and piston group is to be assembled in the engine with the chamfer side of the rod adjacent to the crank pin thrust surface. The opposite side is to thrust against the mating rod on the same crank pin.
14. Put the piston in position on connecting rod (4). Put clean engine oil on pin (2), and install the pin. Install retainer rings (1) with Tool (A). Make sure the retainer rings are in the grooves of the piston.15. Install bearings (3) in the connecting rod and connecting rod cap. Be sure the tabs in back of the bearings are in the tab slots of the connecting rod and connecting rod cap.End By:a. install pistons and connecting rod assemblies