GASKET 4W7435 - Caterpillar

Overhaul Intervals
Some factors that are important for determining the overhaul intervals include the following considerations:
Performance of preventive maintenance
Use of recommended lubricants
Use of recommended coolants
Use of recommended fuels
Proper installation
Operating conditions
Operation within acceptable limits
Engine load cyclesGenerally, engines that are operated at a reduced load and/or speed achieve more service life before an overhaul. However, this service life is for engines that are properly operated and maintained.Other factors must be considered for determining a major overhaul:
The total amount of fuel consumption
The service hours of the engine
An increase of oil consumption
An increase of crankcase blowby
The wear metal analysis of the lube oil
An increase in the levels of noise and vibration
The total number of engine startsAn increase of wear metals in the lube oil indicates that the bearings and the surfaces that wear may need servicing. An increase in the levels of noise and vibration indicates that rotating parts require service.Note: Oil analysis may 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.Service Hours and Fuel Consumption
Experience has shown that maintenance intervals are most accurately based on fuel consumption. Fuel consumption corresponds more accurately to the engine load.Use the actual records of fuel consumption, when possible. If the actual records are not available, use the following procedure to estimate the fuel consumption.Use gallons, hours, or load cycles, WHICHEVER OCCURS FIRST, to determine Overhaul.Operating at greater than 800 m (2625 ft) altitude and 40° C (104° F) ambient conditions for an extended time, may decrease overhaul intervals. Contact your Cat dealer for assistance.
Table 1
Overhaul Schedule
Fuel Consumption 4542492 L (1200000 US gal) 4542492 L (1200000 US gal) 4542492 L (1200000 US gal) 4542492 L (1200000 US gal)
Load Factor < 25 Per Cent 25 - 30 Per Cent 30 - 50 Per Cent > 40 Per Cent
Service Hours 24000 21000 18500 16000
Load Cycles(1)(2) 192000 192000 192000 192000
(1) To illustrate engine capability, a load cycle has been defined as an increase of at least an 80 per cent rated power followed by a decrease of at least 80 per cent rated power. Load cycles of less than 80 per cent rated power may also impact the engine overhaul interval, requiring your specific operating profile to determine your appropriate interval.
(2) Determining the appropriate overhaul interval will require understanding of the locomotive operating profile including total operating hours, amount of fuel burned, load factor, load cycles, and total number of engine starts. Caterpillar requires the use of data recorders to help determine the operating profile and to set appropriate intervals for a fleet on a given route. Changes in operating profiles (a different deployment or change in the