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

WARNING  When using solvents, acids, or alkaline materials for cleaning, following the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

WARNING  Some solvents are flammable and toxic. Read the manufacturer’s instructions before using.

CAUTION  Do not use emery cloth or sandpaper to remove carbon from the cylinder liners. Aluminum oxide or silicon particles from emery cloth or sandpaper can cause serious engine damage. Do not use any abrasives in the ring travel area. The cylinder liner can be damaged.

Use a fine, fibrous, abrasive pad such as Scotch-Brite™ 7448, Part Number 3823258 or equivalent, and solvent to remove carbon from the cylinder liners as needed.

Rotate the crankshaft so that two of the connecting rods are at bottom dead center. Refer to Procedure 009-035 in Section 9.

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.

Do not remove the capscrews at this time.

Loosen the connecting rod capscrews.

Hit the connecting rod capscrews with a rubber hammer to loosen the rod caps.

Remove the capscrews and the rod cap. Note the corresponding rod and rod cap as well as the orientation of the rod cap.

Be careful not to damage the fractured split connection.

DO NOT set the rod cap down on the fractured split face.

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

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.

Remove the bearing shell from the rod cap and mark the cylinder number and the letter “L” on the flat surface of the bearing tangs.

Install two of the capscrews back into the rod finger tight.

Use a T-handle piston pusher. Push only against the head of the capscrew, to push the rod up far enough to allow the upper bearing shell to be removed.

DO NOT push against the fractured split face of the rod.

Use caution not to scratch or damage the journal with the rod, capscrew, or piston pusher.

Remove the bearing shell and mark the cylinder number and the letter “U” on the flat surface of the bearing tangs.

Use both hands to remove the piston and connecting rod assembly.

The piston and connecting rod assemblies must be installed in the same cylinder from which they were removed to provide for proper fit of worn mating surfaces if parts are reused.

Use a tag to mark the cylinder number from which each piston and connecting rod assembly was removed.

Pistons that are reused must be installed in the same orientation as when removed from the engine. Mark the front side of the piston and piston pin with layout ink, or equivalent, after removal.

Place the connecting rod and piston assemblies in a container to protect them from damage.

The two pieces of the connecting rod can not be rubbed together. This will damage the mating surfaces. Use care to not drop either piece of the connecting rod. Fracture split connecting rods must only be handled if the two pieces of the connecting rod are torqued to the correct specification, or completely separated.