BOLT 0S1621 - Caterpillar

Refer to this Operation and Maintenance Manual, "Maintenance Recommendations" to determine the maintenance interval for a major overhaul.The need for a major overhaul is determined by several factors.
An increase of oil consumption
An increase of crankcase blowby
The total amount of fuel consumption
The service hours of the engine
The wear metal analysis of the lube oil
An increase in the levels of noise and vibrationAn increase of wear metals in the lube oil indicates that the bearings and the surfaces that wear may need to be serviced. An increase in the levels of noise and vibration indicates that rotating parts require service.Note: Oil analysis can indicate a decrease of wear metals in the lube oil. The cylinder liners may be worn so that polishing of the bore occurs. Also, the increased use of lube oil will dilute the wear metals.Monitor the engine as the engine accumulates service hours. Consult your Cat dealer about scheduling a major overhaul.Note: The driven equipment may also require service when the engine is overhauled. Refer to the literature that is provided by the OEM of the driven equipment.A major overhaul includes all the work that is done for the top end overhaul. A major overhaul includes more parts and labor. More parts and labor are required to rebuild the engine.For the major overhaul, all the bearings, seals, gaskets, and components that wear are disassembled. The parts are cleaned and inspected. If necessary, the parts are replaced. The crankshaft is measured for wear. The crankshaft may require regrinding. Alternatively, the crankshaft may be replaced with a Cat replacement part.Your Cat dealer can provide these services and components. Your Cat dealer can ensure that the components are operating within the appropriate specifications.Inspection of Components
Inspect the following components according to the instructions that are in Cat reusability publications. Refer to Guidelines for Reusable Parts and Salvage Operations, SEBF8029, "Index of Publications on Reusability or Salvage of Used Parts".
Aftertreatment - CEM housing and mounting structure
Aftertreatment - DEF nozzle
Aftertreatment - dosing cabinet
Aftercooler core
Camshaft
CEM
Crankshaft
Dosing cabinet
Driven equipment (alignment)
Engine cylinder block
Engine control module
Exhaust bellows shields
Flywheel
Front gear train (gears)
Oil suction screen
Rear gear trainInspect the camshaft for damage to the journals and the lobes.Inspect the crankshaft for any of the following conditions:
Deflection
Damage to the journals
Bearing material that has seized to the journalsCheck the journal taper and the profile of the crankshaft journals. Check these components by interpreting the wear patterns on the following components:
Rod bearing
Main bearingsNote: If the crankshaft or the camshaft are removed for any reason, use the magnetic particle inspection process to check for cracks.Replace the crankshaft vibration damper if any of the following conditions occur:
Engine failure due to a broken crankshaft
Excessive wear of the front bearing for the crankshaft
Excessive wear of the gear train that is not caused by a lack of lubricationInspect the gears of the gear train and inspect the gear train bushings for the following conditions:
Worn gear teeth
Unusual fit
Unusual wearIn addition to the inspection of components, inspect the alignment of the driven equipment. See the Application and Installation Guide for the