IDLER & BEARING AS 7T8940 - Caterpillar

Table 1
S O S Oil Analysis Guidelines    
Test Parameter     Guideline    
Oxidation     (1)    
Soot     (1)    
Sulfation     (1)    
Wear Metals     Trend Analysis and Cat Wear Table (1) norms    
Water     0.5% maximum    
Glycol     0%    
Fuel Dilution     4% maximum    
Viscosity - engines by "ASTM D445" measured at
100° C (212° F)     +/-3 centistoke (cSt) change from new oil viscosity.    
Total Base Number (TBN) by "ASTM D2896"     50% of new oil TBN    
Total Acid Number (TAN) by "ASTM D664"     2.0 greater than new oil TAN or 3.0 maximum    
( 1 ) Acceptable values for these parameters are proprietary to the S O S Oil Analysis program.Consult your Caterpillar dealer for complete information and assistance about the S O S Oil Analysis program.Obtaining S O S Oil Samples
Before you obtain an S O S oil sample, operate the engine until the oil is warm and the oil is well circulated. Then obtain the S O S oil sample.In order to obtain a good oil sample, do not take the oil sample from the drain stream. The drain stream method can allow a stream of dirty oil from the bottom of the compartment to contaminate the sample. Likewise, never dip an oil sample from an oil container or pour a sample from a used filter.
Always use a designated pump for oil sampling, and use a separate designated pump for coolant sampling. Using the same pump for both types of samples may contaminate the samples that are being drawn. This contaminate may cause a false analysis and an incorrect interpretation that could lead to concerns by both dealers and customers.
There are two ways to obtain S O S oil samples. The following methods are listed in the order that is preferred:
Use an in-line sampling valve for pressurized oil systems.
Use a sampling gun that is inserted into the sump.Use of the in-line sampling valve is the preferred method. This method provides samples that are less likely to be contaminated. Whenever you obtain the samples, obtain the samples from the same point. This makes the samples more representative of the oil that is in the system.In order to obtain an oil sample from the engine compartment, it may be necessary to increase the engine's speed. Normally, the oil sample is taken at low idle. If the flow rate is too low, increase engine speed to high idle in order to obtain the oil sample.Refer to the Operation and Maintenance Manual, "Maintenance Interval Schedule" for the proper interval.Sampling Interval
Take the oil samples as close as possible to the standard intervals. In order to receive the full value from S O S oil analysis, you must establish a consistent trend of data. In order to establish a pertinent history of data, perform consistent oil samplings that are evenly spaced.
Table 2
Compartment     Engine    
Recommended Sampling Interval    
24140 kilometers (15000 miles)
(1)    
Sampling Valve