Cummins ISX11.9 CM2250 – Service Manual 001-054   Piston and Connecting Rod Assembly

Rotate the crankshaft so the connecting rod journal of the connecting rod being installed is at bottom dead center. Refer to Procedure 009-035 in Section 9.

Immerse the piston in a container of clean 15W-40 oil.

Remove the piston from the container. Let the excess oil drain from the piston.

Use a clean, lint-free cloth to clean the connecting rods and bearing shells.

Do not lubricate the backside of the bearing shells. The operating clearance of the bearing will be reduced and the bearing can be damaged during engine operation.

If new bearings are not used, the used bearings must be installed on the same connecting rod from which they were removed.

Install the upper bearing shell into the connecting rod.

The tang of the bearing shell (2) must be in the slot of the cap (1). The end of the bearing shell must be even with the cap mounting surface.

Use Lubriplate™ 105, Part Number 3163086 or equivalent, to coat the entire inside circumference of the bearing shell.

Apply a film of clean 15W-40 oil to the cylinder liner.

Inspect the cylinder liners for reuse. Refer to Procedure 001-028 in Section 1.

Apply a film of clean 15W-40 oil to the cylinder liner.

Use piston ring compressor, Part Number 4919273, to compress the rings.The cylinder block and all parts must be clean before assembly.

Install two guide pins, Part Number 3163097, in the connecting rod.

For pistons that are being reused, the piston, piston pin, and connecting rod must be installed in the same orientation from which they were removed from the engine.

The long side of the connecting rod will be on the left side of the engine and the short side of the connecting rod will be on the right side of the engine when properly installed.

CAUTION  Do not use a metal drift to push the piston into the cylinder liner. The piston rings or cylinder liner can be damaged.

Hold the ring compressor against the cylinder liner. Push the piston through the ring compressor and into the cylinder liner. Push the piston until the top ring is completely in the cylinder liner.

If the piston does not move freely, remove the piston and inspect for broken or damaged rings.

Align the connecting rod with the crankshaft while pushing the piston and connecting rod assembly into place.

Install the bearing shell into the connecting rod cap with the tang (2) of the bearing in the slot (1) of the cap.

Use clean Lubriplate™ 105 multi-purpose lubricant, or equivalent, to lubricate the bearing shell to crankshaft journal mating surface.

CAUTION  Do not damage the fractured split surface on the connecting rod or connecting rod cap while the connecting rod caps are removed. If the fractured split surface is damaged, the connecting rod and connecting rod cap must be replaced to reduce the possibility of engine damage. Incorrect assembly can damage the rod.

NOTE: Make sure that the rod cap is installed only on the connecting rod from which it was removed, and that the rod cap is properly oriented when installing.

NOTE: Both the rod cap and the connecting rod are serialized on one face to make sure of proper orientation.

Install the cap onto the connecting rod.

NOTE: Minimize the number of joint interactions between the connecting rod and rod cap. There is only a finite number of times a connecting rod and rod cap can be assembled and removed before the joint loses its proper interaction.

Lubricate the threads and underside of the head of the connecting rod capscrews with clean engine oil.

Thread the capscrews into the connecting rod and hand tighten.

Tighten the capscrews in numerical sequence.

Measure the connecting rod side clearance.

Connecting Rod Side Clearance

The connecting rod must move freely from side to side on the crankshaft journal. If the rod does not move freely, remove the rod cap and make sure the bearing shells are the correct size. Check for dirt or damage on the crankshaft and the bearing shells.

Repeat the above steps to install the remaining bearing shells and connecting rod caps.