N14 Base Engine Troubleshooting and Repair Manual – 001-014   Connecting Rod

Remove the piston and connecting rod assemblies from the engine.
Refer to Procedure 001-054 in Section 1.

NOTE: The piston and connecting rod assemblies
must be installed in the same cylinder number from which they were removed, to make sure there is a correct fit of worn mating surfaces if parts are used again.

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

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow 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.

WARNING  When using a steam cleaner, wear safety glasses or a face shield, as well as protective clothing. Hot steam can cause serious personal injury.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

Use a nylon bristle brush to clean the oil drillings.

Steam clean or use solvent to clean the connecting rods.

Dry with compressed air.

Inspect the rods and the caps for damage.

Replace the rod if the “I-beam” is nicked or damaged.

Inspect the connecting rod and the cap for fretting damage on the mating surfaces.

The rod and the cap
must be replaced as an assembly if any fretting damage is visible on either piece.

Inspect the rod pin bore bushing for damage or misalignment of the oil passage and the bushing.

Replace any piston pin bushing that has evidence of scoring, galling, or scuffing. Replace any bushing that has turned.

Special tools and precision machining are required to replace bushings. If Cummins® approved tools and procedures are
not available, the connecting rod
must be replaced.

CAUTION  The rod cap alpha characters must match the alpha characters on the connecting rod and must be installed with the characters aligned to prevent damage to the connecting rods and crankshaft.

Install the connecting rod caps and the capscrews.

Refer to Procedure 001-047 in Section 1.

Measure the rod crankshaft bore inside diameter.

If any of the measurements are
not within the specifications, the rod
must be repaired or replaced.

Measure the piston pin bushing inside diameter.

If any of the measurements are
not within the specifications, the rod
must be repaired or replaced.

The bushing
must be precision machined after installation. If machining capability is available, the bushing can be replaced. Refer to the Alternative Repair Manual, Bulletin 3379035.

Remove the capscrews and the rod caps.

NOTE: Refer to the Engine Shop Manual to measure the bend and twist of the rods.

Measure the connecting rod capscrew outside diameter.

Install the piston and connecting rod assembly.
Refer to Procedure 001-054 in Section 1.