CONE, BEARING 775241 - Caterpillar

Probable Causes
Diagnostic codes
Event codes
Starting aids
Throttle signal
Electrical connectors
Unit injectors
Injection actuation pressure
Fuel supply
Turbocharger outlet pressure sensor
Air inlet and exhaust systemRecommended Actions
Note: If the problem only occurs under certain conditions, test the engine under those conditions. Examples of certain conditions are high engine speed, full load and engine operating temperature. Troubleshooting the symptoms under other conditions can give misleading results.Diagnostic Codes and Event Codes
Certain diagnostic codes and/or event codes may cause poor performance. Connect the Caterpillar Electronic Technician (Cat ET) and check for active codes and/or logged codes. Troubleshoot any codes that are present before continuing with this procedure.Starting Aids
Cold Mode
Use Cat ET to verify that the engine has exited cold mode. If the engine is operating in cold mode, an indicator will be displayed on the top of any of the status screens on Cat ET. Cold mode operation may slow throttle response.Air Inlet Heater
Ensure that the air inlet heater is functioning properly. Refer to Troubleshooting, "Air Inlet Heater Circuit - Test" for additional information.Throttle Signal
Monitor the throttle signal on Cat ET. Verify that the throttle is operating correctly. Refer to Troubleshooting, "Throttle Position Sensor Circuit - Test" for additional information.Electrical Connectors
Check the J1/P1 ECM connector, the J2/P2 ECM connector, the J300/P300 unit injector connector, the connectors for the throttle position sensor, and the associated wiring for damage, abrasion, corrosion, or incorrect attachment. Refer to Troubleshooting, "Electrical Connectors-Inspect" for additional information.Unit Injectors
Perform the Injector Solenoid Test on Cat ET in order to determine if all of the injector solenoids are being energized by the ECM.
Perform the Cylinder Cutout Test on Cat ET in order to identify any injectors that might be misfiring. Refer to Troubleshooting, "Injector Solenoid Circuit - Test" for the proper procedure.Injection Actuation Pressure
Check the engine oil level. Engine oil is used to activate the high pressure hydraulic pump.
Ensure that the engine oil meets the recommendations. Refer to Operation and Maintenance Manual for additional information.
Crank the engine and monitor the injection actuation pressure and the output of the injection actuation pressure control valve. The high pressure oil system is operating properly if the pressure output is a minimum of 6 MPa (870 psi).Fuel Supply
Check the fuel lines for the following problems: restrictions, collapsed lines and pinched lines. If problems are found with the fuel lines, repair the lines and/or replace the lines.
Check the fuel tank for foreign objects which may block the fuel supply.
Check for air in the low pressure fuel supply system if any of the following procedures have been performed:
Replacement of the fuel filters
Service on the low pressure fuel supply circuit
Replacement of unit injectorsNote: A sight glass in the low pressure supply line is helpful in diagnosing air in the fuel. Refer to Testing and Adjusting for more information.
Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.
Purge air from the low pressure fuel supply circuit. Refer to Operation and Maintenance Manual, "Fuel System - Prime" for the correct procedure.
Check fuel