SPRING 4N8150 - Caterpillar

3408, 3412, 3508, 3512 Industrial, Marine And Generator Set EnginesDescription of Change: Improvements have been made to the auxiliary sea water pumps used on the above engines. A thicker nut is used for mounting the impeller to allow a higher torque. Also, a new shaft has two cross-drilled holes for the cotter pin instead of the one hole used in the former shaft. The two holes require less adjustment on the nut for aligning the cotter pin with the slot in the nut. With these changes, the torque for the nut has been increased from 60-70 N m (44-50 lb ft) to 160 N m (120 lb ft).Adaptable To: The new 7C3613 Pump Group is a direct replacement for the former 3N7790 Pump Group which is canceled and is adaptable to 3408 Industrial and Marine Engines and 3412 Industrial, Marine and Generator Set Engines. The new 7C3614 Pump Group is a direct replacement for the former 5N2600 Pump Group which is canceled and is adaptable to all of the above engines except 3408 Industrial Engines. The new 7C3493 Shaft and 8C503 Nut replace the former 3N8451 Shaft which is canceled.