0320115 JOHNSON THRUST WASHER

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 lists average ranges of fuel consumption and service hours for a load factor of approximately 60 percent.
Table 1
Maintenance Interval Schedule
Service Hours and Fuel Consumption for the 3508B Industrial Engine (1)
Interval Rated 1601 to 1800 RPM
250 Service Hours 32,000 L (8500 US gal)
500 Service Hours 64,000 L (17,000 US gal)
1000 Service Hours 128,000 L (34,000 US gal)
2000 Service Hours 257,000 L (68,000 US gal)
3000 Service Hours 386,500 L (102,000 US gal)
6000 Service Hours 774,000 L (204,000 US gal)
Top End Overhaul 7500 Service Hours
1,000,000 L (264,000 US gal)
Second Top End Overhaul 15,000 Service Hours
2,000,000 L (528,000 US gal)
Major Overhaul 22,500 Service Hours
3,000,000 L (792,000 US gal)
(1) Fuel consumption is based on a load factor of approximately 60 percent.Use the actual records of fuel consumption, when possible. If the actual records are not available, use the following procedure in order to estimate the fuel consumption.
Estimate the average percent of the load for the operation of the engine.
Refer to the fuel consumption data in the Technical Marketing Information (TMI) for your engine. This will determine the fuel consumption for the percent of the load that was estimated in Step 1. Use this figure as variable "F" for the equation in Table 2. For more information about the Technical Marketing Information (TMI) for your engine, consult your Caterpillar dealer.
Table 2
Equation For Calculating Overhaul Intervals
F/R = H
“F” is the estimated total amount of fuel consumption of the engine.
“R” is the rate of fuel consumption in liters per hour or gallons per hour.
“H” is the number of estimated hours until the overhaul interval. Oil Consumption as an Overhaul Indicator
Oil consumption, fuel consumption, and maintenance information can be used to estimate the total operating cost for your Caterpillar engine. Oil consumption can also be used to estimate the required capacity of a makeup oil tank that is suitable for the maintenance intervals.Oil consumption is in proportion to the percentage of the rated engine load. As the percentage of the engine load is increased, the amount of oil that is consumed per hour also increases.The oil consumption rate (brake specific oil consumption) is measured in grams per kW/h (lb per bhp). The brake specific oil consumption (BSOC) depends on the engine load. Consult your Caterpillar dealer for assistance in determining the typical oil consumption rate for your engine.When an engine's oil consumption has risen to three times the original oil consumption rate due to normal wear, an engine overhaul should be scheduled. There may be a corresponding increase in blowby and a slight increase in fuel consumption.Severe Operation
Severe operation is the use of an engine that exceeds current published standards for that engine. Caterpillar maintains standards for the following engine parameters:
Horsepower
Range of rpm
Fuel consumption
Fuel quality
Altitude
Maintenance intervals
Selection of oil
Selection of coolant
Environmental qualities
InstallationRefer to the standards for your engine or consult your Caterpillar dealer in order to determine if your engine is operating within the defined parameters.Severe operation can accelerate component wear. Engines that are operating under severe conditions may need more frequent maintenance intervals for the following reasons:
Maximum reliability
Retention of full service lifeBecause of individual applications, it is not possible to identify all of the factors which can contribute to severe operation. Consult your Caterpillar dealer about the maintenance that is needed for your specific engine.The following factors can contribute to severe operation: environment, improper operating procedures and improper maintenance practices.Environmental Factors
Extreme Ambient Temperatures
Extended operation in environments that are extremely cold or hot can damage components. Valve components can be damaged by carbon buildup if the engine is frequently started and stopped in very cold temperatures. Extremely hot inlet air reduces the performance capabilities of the engine.Note: See this Operation and Maintenance Manual, "Cold Weather Operation" topic (Operation Section), or see Supplement, SEBU5898, "Cold Weather Recommendations".Cleanliness
Unless the equipment is cleaned regularly, extended operation in a dirty environment and in a dusty environment can damage components. Built up mud, dirt, and dust can encase components. This can make maintenance difficult. The buildup can contain corrosive chemicals. Corrosive chemicals and salt can damage some components.Improper Operating Procedures
Extended operation at low idle
Minimum cool down periods after high load factor operation
Operating the engine beyond the guidelines for the engine rating
Operating the engine at loads that are greater than the rated load
Operating the engine at speeds that are greate