NUT-SLOTTED 1K6863 - Caterpillar

Introduction
Caterpillar recommends reading and understanding this procedure completely before attempting any of the repairs that are described.This procedure was developed in order to provide a higher quality and a lower cost repair for a broken crankshaft.Inspection and/or Repair Procedure to Replace Broken Crankshafts in 3406C, C-15, C-16, C15, 3406E, and 3456 Engines
Remove the engine from the chassis.
Remove all the rod caps from all of the connecting rods.
For each connecting rod, inspect the large end of the rod bore, parting line area, all connecting rod caps, hardware seating area, lower shank area, and hardware for damage. Refer to Visual Inspection of Connecting Rods, SEBF8063, "Guidelines for Reusable Parts and Salvage Operations" and Salvage of Non-Serrated Connecting Rods, SEBF8064, "Guidelines for Reusable Parts and Salvage Operations" for more information. Also inspect the bottom ends of each piston skirt and each liner for damage. If there is no indication of damage to the components in the upper end, it is not necessary to inspect the small end of the connecting rod. If the connecting rods are OK for use proceed to Step 4. If the connecting rods are damaged replace the connecting rods with a Reman version. Also, if the piston is damaged, the cylinder pack must be replaced. Refer to ""Alternative Repair Options"" for more information.
Push the piston and the connecting rod up to the top of the liner bore.
Remove the main bearings, thrust plates, and the crankshaft. Remove the oil filter from the engine. In order to inspect the oil filter for evidence of metal debris, the oil filter must be cut open. The oil pump and oil filter base must be disassembled, inspected, and cleaned if debris is present and the debris exceeds three particles (1 mm) per pleat. The oil cooler core must be replaced with a Reman part. Continue to inspect all main bearings for scratches due to debris. Scratches on the main bearing due to debris indicate that metal particles exist on the filtered side of the lubrication system. If scratches due to debris are present on one or more of the main bearings, the complete lubrication system must be flushed.
Inspect the main bearing bore diameter of the cylinder block for damage. If there are no signs of damage proceed to Step 7. If damage is present and the damage is due to a buildup of irregular material, proceed to Step 6.a.
Position the engine in a vertical position in order to avoid contamination from debris. Remove any debris or remove any buildup of a metal ridge from the main bearing bore with a small pencil grinder.Note: Remove enough of the metal buildup in order to allow the new main bearing to fully seat in the bore. Do not use an emery cloth over the large area of the bore. Use magnets to avoid further contamination from debris. It may be necessary to machine the main bore