821280 Mercury NUT (SEA PRO/MARATHON 25/SUPER 15)

Table 1
Required Tools
Tool Part Number Part Description Qty
A 1U-8221 Lifting Sling 2
B 8T-3052 Degree Wheel 1
C 9U-7324 Indicator Bracket 1
7H-1942 Dial Indicator 1
3S-3268 Indicator Contact Point 1
7H-1940 Universal Attachment 1
D - Loctite 5900 -
E - Straight Edge 1
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Clean the crankshaft and inspect the crankshaft for wear and damage. Refer to Specifications, "Crankshaft" for more information. If necessary, replace the crankshaft or recondition the crankshaft.
If necessary, install the crankshaft gear. Refer to Disassembly and Assembly, "Crankshaft Gear - Remove and Install" for the correct procedure.
Ensure that parent bores for bearing shells in the cylinder block are clean. Ensure that the threads for the main bearing bolts in the cylinder block are clean and free from damage.
Clean the main bearing shells and the thrust washers. Inspect the main bearing shells and the thrust washers for wear and damage. If necessary, replace the main bearing shells and the thrust washers. Note: If the main bearing shells are replaced, check whether oversize main bearing shells were previously installed. If the thrust washers are replaced, check whether oversize thrust washers were previously installed.
Illustration 1 g02725177
Install upper main bearing shells (11) to the cylinder block. Ensure that the locating tabs for the upper main bearing shells are seated in the slots in the cylinder block. Note: The upper main bearing shells have a groove and two oil holes.
Lubricate upper main bearing shells (11) with clean engine oil.
Illustration 2 g02725176
Attach Tooling (A) and a suitable lifting device to crankshaft (10). Lift crankshaft (10) into the cylinder block. The weight of the crankshaft is approximately 61 kg (134 lb). Note: Do not damage any of the finished surfaces on the crankshaft. Do not damage the main bearing shells.
Illustration 3 g02725175
Lubricate thrust washers (9) with clean engine oil. Install thrust washers (9) into number six main bearing in the cylinder block. Note: The grooves in the thrust washers must be located against the crankshaft. The thrust washers have a locating tab at one end. Ensure that the locating tabs are correctly seated in the cylinder block.
Illustration 4 g02725203
Install lower main bearing shells (8) into main bearing caps (7). Ensure that the locating tabs for the lower main bearing shells are correctly seated into the slots in the bearing caps. Note: The lower main bearing shells are plain bearings that do not have oil holes.
Lubricate lower main bearing shells (8) and lubricate the journals of the crankshaft with clean engine oil. Install main bearing caps (7) to the cylinder block. Note: Ensure the correct location and orientation of main bearing caps (7). The locating tabs for the upper and the lower main bearing shells should be on the same side of the engine.
Illustration 5 g02725218
Lubricate the threads of bolts (6) with clean engine oil. Lubricate the underside of the heads of bolts (6) with clean engine oil.
Install bolts (6) to main bearing caps (7). Evenly tighten the bolts in order to pull the caps into position. Ensure that the caps are correctly seated. Note: Do not tap the main bearing caps into position as the bearing shells may be dislodged.
Tighten bolts (6) to a torque of 80 N m (59 lb ft). Turn bolts (6) through an additional 90 degrees. Use Tooling (B) to achieve the final torque.
Rotate the crankshaft in order to ensure that there is no binding.
Illustration 6 g01399694
Check the crankshaft end play. Push the crankshaft toward the front of the engine. Install Tooling (C) to the cylinder block and the rear face of the crankshaft. Push the crankshaft toward the rear of the engine. Use Tooling (C) to measure the crankshaft end play. The permissible crankshaft end play is 0.10 mm (0.004 inch) to 0.41 mm (0.016 inch).
Illustration 7 g02724705
If necessary, follow Step 16.a through Step 16.c in order to install the cross over tube assembly from the cylinder block.
Remove bolts