| Component or System | Oil Change Interval | Sampling Interval | Sampling Valve |
| Engine | 250 Hours | 250 Hours | No |
| Hydraulics | 500 Hours | 500 Hours | Yes |
| Final Drive Planetary | Initial 50 Hours and 500 Hours | Initial 50 Hours and 500 Hours | No |
| Differential | 500 Hours or 3 Months | 500 Hours or 3 Months | No |
| Propel Transmission | 500 Hours or 3 Months | 500 Hours or 3 Months | No |
| Rotor Transmission | 500 Hours or 3 Months | 500 Hours or 3 Months | Yes |
| Rotor Drive Differential | 500 Hours or 3 Months | 500 Hours or 3 Months | Yes |
 | |
| Illustration 1 | g00755426 |
The oil sample for the engine oil is obtained through the crankcase drain valve.
 | |
| Illustration 2 | g00755418 |
The hydraulic oil sampling valve is located next to the propel pump.
 | |
| Illustration 3 | g00755432 |
The oil sample for the final drive planetary is obtained when the planetary oil is changed through the drain plug. Use the procedure for changing the oil for the final drive to drain and refill the final drive planetary.
 | |
| Illustration 4 | g00755433 |
The oil sample for the differential is obtained when the differential oil is drained through the drain plug. Use the procedure for changing the oil for the differential to drain and refill the differential.
 | |
| Illustration 5 | g00761614 |
The oil sample for the propel transmission is obtained when the oil for the propel transmission is drained through the drain plug. Use the procedure for changing the oil for the propel transmission to drain and refill the propel transmission.
 | |
| Illustration 6 | g00755436 |
The oil sampling valve for the rotor transmission is located on the oil cooler for the rotor.
 | |
| Illustration 7 | g00755435 |
The oil sampling valve for the rotor drive differential is located on the oil cooler for the rotor.
Consult your Caterpillar dealer for complete information and assistance in establishing an S·O·S program for your equipment.
More Frequent S·O·S Sampling Improves Life Cycle Management
Traditionally, the suggested S·O·S sampling intervals have been at each oil change, 250 hours for engines, or every 500 hours for all other compartments. A sampling interval of 250 hours is recommended for all compartments.
Application
A 500 hour sampling interval does not give advanced notice of failures in some high load conditions and in some high temperature conditions. A 250 hour sampling interval provides more data between oil change intervals. This increases the chance for detecting a potential failure.
Determining Superior Oil Change Intervals
Sampling compartments at every 250 hours provides information on oil performance in order to determine the best utility of a particular oil. Sampling more often can allow closer monitoring of component wear rates. For detailed information on extending oil change intervals, please see your Caterpillar dealer.
Optimizing Component Life
A decreased sampling interval provides better trends of data. A decreased sampling interval enables close monitoring of wear patterns on components. This will ensure full component life.