31330322 Volvo.Penta Main bearing

Table 1
Required Tools
Tool Part Number Part Description Qty
A 1P-1857 Retaining Ring Pliers 1
B 1U-6683 Ring Expander 1
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Ensure that all components are clean and free from wear and damage. If necessary, replace any components that are worn or damaged.
If the original piston is assembled, follow Step 2.a through Step 2.e in order to install the piston rings.
Position the spring for oil control ring (3) into the oil ring groove in piston (4). The central wire must be located inside the end of the spring.
Illustration 1 g02090036
Position the oil control ring with the word "TOP" in the upward position and use Tooling (B) to install oil control ring (3) over the piston and the spring. Note: Ensure that the central wire is 180 degrees from the ring gap.
Use Tooling (B) to install intermediate compression ring (2) into the second groove in piston (4). The word "TOP" must be upward. The chamfer on the inner face must be downward.
Use Tooling (B) to install top compression ring (1) into the top groove in piston (4). The word "TOP" must be upward.
Position the piston ring gaps at 120 degrees away from each other. Note: A new piston assembly is supplied with new piston rings.
Removal of the piston pin bushing in the connecting rod must be carried out by personnel with the correct training. Also special machinery is required. For more information refer to your authorized Caterpillar dealer.
If connecting rod assembly (6), the bush for piston pin (8), connecting rod cap (11), and bolts (12) or the bush for piston pin (8) is replaced, refer to Specifications, "Connecting Rods" for further information.
Illustration 2 g02513777
Illustration 3 g02514076
Illustration 4 g02514164
Aligning the connecting rod bearing in the center of the connecting rod
Lubricate the bush for piston pin (8) in connecting rod (6) with clean engine oil.
Lubricate the bore for the piston pin in piston (4) with clean engine oil.
Place piston (4) on a suitable surface with the crown downward. Position connecting rod (6) with the forged Mark (X) to the square (13) on the piston.
Install piston pin (7) to piston (4). Note: If the piston pin cannot be installed by hand, heat the piston to a temperature of 45° 5°C (113° 9°F).
Use Tooling (A) in order to install circlips (5) to the piston pin bore in piston (4). Note: Ensure that the circlips are seated in the grooves in the piston.
Install upper bearing shell (9) into connecting rod (6). Ensure that the bearing is centralized in the connecting rod. Refer to 4.
Install lower bearing shell (10) into connecting rod cap (11). Ensure that the bearing is centralized in the connecting rod. Refer to 4.
Repeat Step 2 through Step 10 for the remaining piston and connecting rod assemblies. Note: Fracture split connecting rods should not be left without the connecting rod caps installed. After the assembly procedure for the piston and connecting rod is completed, carry out the installation procedure as soon as possible. Refer to Disassembly and Assembly, "Piston and Connecting Rods - Install" for the correct procedure.End By:
Install the pistons and the connecting rods. Refer to Disassembly and Assembly, "Piston and Connecting Rods - Install" for the correct procedure.