Cummins N14 – Crankshaft – Inspection

Visually inspect the machined surfaces for scratches or nicks.
Use a fine crocus cloth to remove the nicks and scratches.
NOTE: If scratches or nicks can be felt with a fingernail after the crankshaft has been polished with a crocus cloth, the
crankshaft must be replaced or reconditioned.

Visually inspect the threaded capscrew holes for damage.
Use one of the following methods to repair any threaded holes:
1. Use a tap to clean the burrs from the threads.
2. Use a thread repair insert.
If necessary, refer to the Alternative Repair Manual, Bulletin No. 3379035, for repair instructions.

NOTE: A maximum of 50 percent of the threaded holes per crankshaft end can be repaired.

Visually inspect the crankshaft gear for cracks and broken or chipped teeth.

Where the front and the rear crankshaft seals contact the crankshaft, the maximum allowable wear is 0.13 mm
[0.005 in].

Measure the crankshaft gear fit area outside diameter (if the gear has been removed).

Measure the front oil seal area outside diameter.

Measure the rear oil seal area outside diameter.

Crankshafts which are ground oversize in the thrust face width are normally marked on the rear counterweight.
Crankshafts which are ground undersize in the connecting rod or the main bearing journals are normally marked
on the front counterweight.

Measure the connecting rod journals outside diameters.

Measure the main bearing journals outside diameter.

Measure the thrust face width.

The crankshaft can be ground undersize if the bearing journals or the thrust distance is not within specifications.
Always grind all the journals when one is not within specifications.
Oversize rod bearings, main bearings, and thrust bearings are available.
Refer to the Alternative Repair Manual, Bulletin No. 3379035, for grinding specifications and instructions.

Refer to the Alternate Repair Manual, Bulletin No. 3379035, for procedures to magnetically check for cracks
in the crankshaft and gear.

Use clean 15W-40 oil to lubricate the entire crankshaft to prevent rust.