0435143 JOHNSON ENGINE COVER, Jo., 8R

1. Turn the crankshaft until the timing mark "C" on crankshaft gear (2) is in alignment with the timing mark "C" on camshaft gear (1) as shown. To keep the engine timing correct during removal and installation of the crankshaft, put a mark on the teeth of the fuel injection pump drive gear and idler gear at location (A). Put a mark on the teeth of the idler gear and camshaft gear at location (B). The engine timing will be correct when the marks at locations (A) and (B) are in alignment and the timing marks on the crankshaft and camshaft gears are in alignment. 2. Install a 3/4"-16 NF bolt in the gear end of the crankshaft. Install two 5/8"-18 NF bolts in the flywheel end of the crankshaft. Fasten a nylon strap and a hoist to the crankshaft as shown.3. Remove main bearing cap bolts (4) and main bearing caps (3) from the engine. 4. Remove thrust bearings (5) from each side of the rear main bearing.
Be careful not to damage the crankshaft journals when the crankshaft is removed.
5. Remove crankshaft (7) from the cylinder block. The weight of the crankshaft is approximately 65 Kg (143 lb.).
If new main bearings are not to be installed during crankshaft installation, put identification marks on the original bearings as to their location in the engine.
6. Remove crankshaft main bearings (6) from the cylinder block and from the main bearing caps.7. Check the condition of the main bearings and crankshaft. Make reference to Guideline For Reusable Parts: Main And Connecting Rod Bearings, Form No. SEBF8009 and Visual Inspection Of Crankshafts, Form No. SEBF8043. 8. Use tooling (A), and remove crankshaft gear (2) from the crankshaft.Install Crankshaft And Gear
1. Heat crankshaft drive gear to a maximum temperature of 315° C (600° F). Install drive gear (2) on the crankshaft with the "C" mark on the gear toward the pulley end of the crankshaft. 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 (A) 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") the readings may be low by 0.013 to 0.025 mm (.0005 to .0010"). 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.
Make sure the upper and lower halves of the main bearings are installed so the bearing tabs fit into the notch in the cylinder block and main bearing caps.
2. If the bearings were removed from the engine, clean the surfaces in the cylinder block for the main bearings. Install upper main bearing halves (6) (bearings with the oil hole) in the cylinder block.3. Fasten a nylon strap and a hoist on the crankshaft (7), and put it in position in the cylinder block with the "C" marks on the camshaft drive gear and crankshaft drive gear in alignment. Install the bearings dry when the clearance checks are made. Put clean engine oil on all the bearings for final assembly.4. Check the main bearing clearances with Plastigage (A) as follows:a. Put a piece of Plastigage (A) in position as shown.
Make sure the part number on the main bearing cap is toward the front of the engine and the number on the main bearing cap is the same as the number on the cylinder block on the left side of each main bearing cap.
Do not turn the crankshaft when Plastigage (A) is in position.b. Install main bearing caps. Put clean engine oil on the bolt threads and the face of the washers, and install the bolts. Tighten the bolts to a torque of 40 4 N m (30 3 lb.ft.).c. Put a mark on each bolt and main bearing cap; then tighten the bolts 90° moe.d. Remove the main bearing caps. Measure the Plastigage. The main bearing clearance must be 0.076 to 0.165 mm (.0030 to .0065 in.). The maximum permissible clearance with used bearings is 0.25 mm (.010 in.). 5. Put clean engine oil on thrust bearing (5) for the rear main bearing. Install a thrust bearing