COVER 2850823 - 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
Engine speedGenerally, engines that are operated at a reduced load and/or speed achieve more service life before an overhaul. However, this is for engines that are properly operated and maintained.Other factors must also 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 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: It is possible for oil analysis to 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.Using Fuel Consumption For Calculating the Overhaul Intervals
Experience has shown that maintenance intervals are most accurately based on fuel consumption. Fuel consumption corresponds more accurately to the engine load. Table 1 list average ranges of fuel consumption and service hours for a load factor of approximately 60 percent.High Displacement Engines
Table 1
Service Hours and Fuel Consumption for 3516C High Displacement Engines(1)
Interval Rated Up to 1300 RPM Rated 1301 to 1600 RPM Rated 1601 to 1800 RPM
250 Service Hours 44000 L (11600 US gal) of fuel 53000 L (14000 US gal) of fuel 81500 L (21500 US gal) of fuel
500 Service Hours 88000 L (23200 US gal) of fuel 106000 L (28000 US gal) of fuel 162500 L (43000 US gal) of fuel
1000 Service Hours 176000 L (46500 US gal) of fuel 212000 L (56000 US gal) of fuel 327400 L (86500 US gal) of fuel
2000 Service Hours 352000 L (93000 US gal) of fuel 424000 L (112000 US gal) of fuel 654500 L (173000 US gal) of fuel
3000 Service Hours 528700 L (139500 US gal) of fuel 636700 L (168000 US gal) of fuel 984000 L (260000 US gal) of fuel
6000 Service Hours 1056000 L (279000 US gal) of fuel 1272000 L (336000 US gal) of fuel 1968500 L (520000 US gal) of fuel
Top End Overhaul 11000 Service Hours 9000 Service Hours 7500 Service Hours
2460500 L (650000 US gal) of fuel
Major Overhaul 22000 Service Hours 18000 Service Hours 15000 Service Hours
4921000 L (1300000 US gal) of fuel
(1) Fuel consumption is based on a load factor of