0311415 JOHNSON SCREW.IDLE STOP

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.
Illustration 1 g02319675
If the original piston and rings are to be reused, follow Step 2.a through Step 2.e in order to install the piston rings to the piston.
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.
Position the oil control ring with the word "TOP" in the upward position. 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. Note: Ensure that the top compression ring is installed with Chamfer (W) in the upward position.
Position the piston ring gaps at approximately 120 degrees away from each other. Note: A new piston assembly is supplied with new piston rings.
Illustration 2 g02210673
Illustration 3 g02090053
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), bushing (8) and piston pin (7) are replaced, refer to Specifications, "Connecting Rods" for more information.
Lubricate bushing (8) for piston pin (7) in the connecting rod 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 forged Mark (X) to square boss (14) on the piston. Ensure that slot (13) on the connecting rod is in the correct position. See Illustration 3.
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 locating tab for the upper bearing shell is correctly seated in slot (13) 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.
Fracture split connecting rods should not be left without the connecting rod caps installed. Temporarily install connecting rod cap (11) and bolts (12) to connecting rod (6) when the assembly is out of the engine. Ensure that the etched number on connecting rod cap matches the etched number on connecting rod. Ensure the correct orientation of the connecting rod cap. The locating tab for the upper bearing shell and the lower bearing shell should be on the same side. Tighten bolts (12) to a torque of 20 N m (177 lb in).
Repeat Step 2 through Step 10 for the remaining piston and connecting rod assemblies. End By:
Install the pistons and the connecting rods. Refer to Disassembly and Assembly, "Piston and Connecting Rods - Install" for the correct procedure.