GASKET 7N4251 - Caterpillar

Assembly Procedure
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 or 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 g01341312
Use Tooling (B) to install oil control ring (3) over 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.
Illustration 2 g01341306
Illustration 3 g01341313
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) or bush (8) is replaced, ensure that the height grade of the connecting rod is correct. Refer to Specifications, "Connecting Rods" for further information.
Lubricate bush (8) in the connecting rod and lubricate the bore for the piston pin in piston (4) with clean engine oil.
Place the piston on a suitable surface with the crown downward. Install connecting rod (6) and piston pin (7) to piston (4). Ensure that square (14) on the piston, and slot (13) on the connecting rod are in the correct position. See illustration 3. 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 locating tab for the upper bearing shell is correctly seated in the slot in the connecting rod.
Install lower bearing shell (10) into connecting rod cap (11). Ensure that the locating tab for the lower bearing shell is correctly seated in the slot in the connecting rod cap.
Repeat Step 2 through Step 8 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