SHAFT-PINION 8V8035 - Caterpillar

Probable Causes
Plugged oil filter or faulty oil filter
Faulty oil pressure sensor and/or circuit
Malfunctioning of the oil filter bypass valveRecommended Repairs
Check the Oil Filters
Check the oil filter differential pressure. Do not allow the differential pressure to exceed 103 kPa (15 psi). If the oil filter differential pressure is too high, change the oil filter elements.Inspect the oil filters for good condition. Replace any suspect oil filter.Check the Oil Pressure Sensors and/or Circuits
Use the Caterpillar Electronic Technician (ET) to compare the readings of the filtered oil pressure and the unfiltered oil pressure while the engine is OFF. Make sure that the sensors are correctly wired.If the readings are not approximately zero for both of the sensors, troubleshoot the sensor circuit(s). Refer to Troubleshooting, "Analog Sensor Signal".Check the Oil Filter Bypass Valve
An oil filter bypass valve that is stuck in the closed position can cause a high reading for differential pressure when the oil is cold. An oil filter bypass valve that is stuck in the open position can cause a low reading for differential pressure when the oil is hot. Check the operation of the oil filter bypass valve. For more information, refer to Systems Operation/Testing and Adjusting, "Measuring Engine Oil Pressure".If the oil filter bypass valve is faulty, repair the valve, when possible. Replace the valve, if necessary.