BRACKET AS- 3581147 - Caterpillar

Testing The Oil Supply To the Interaxle Differential
Test the supply pressure for the transfer gear. Refer to Systems Operation/Testing and Adjusting, "Power Train Pressures".Select the interaxle differential lock and test the pressure of the oil at the test point. Refer to Systems Operation/Testing and Adjusting, "Power Train Pressures".If both pressures are below the specification, there is a possibility that the relief valve is not functioning correctly. Replace the relief valve and test the oil pressures again.Testing The Solenoid
To test function of solenoid (1) in the solenoid and relief valve group, run the engine at low idle. Test the pressure at the test point. Refer to Systems Operation/Testing and Adjusting, "Power Train Pressures". Observe the gauge and select the interaxle differential lock. If a rise in the pressure is noted, then the solenoid is allowing oil to the interaxle differential lock. If a pressure rise is noted, the solenoid and the related electrical circuit are functioning correctly.If there is no rise in the pressure, then the solenoid plunger is not moving.If a pressure rise is not noted, use a tag wire to check that the solenoid coil is energized. If the tag wire is attracted to the solenoid, the coil is energized. The problem is in the solenoid cartridge. The problem could be a bent solenoid stem, a screen that is dirty or plugged, or a spring that is weak or broken.If the tag wire does not indicate that the solenoid coil is energized, the problem may be in the electrical circuit.Test the interaxle differential lock. If the solenoid does not function correctly, the problem may be the interaxle differential lock switch or with the wiring harness of the machine.If the solenoid does not appear to function, disconnect the connector for the solenoid valve. Check the resistance of the windings of the coil in the solenoid. The resistance of the windings in the solenoid should be 32.6Ω 1.6Ω.If the resistance of the windings is outside the specifications, replace the solenoid.Pressure In The Interaxle Differential Lock
If the solenoid and relief valve group functions correctly and pressure is correct, interaxle differential lock failure could be from leaking seals of the clutch. A failure could also be a result of damage to the internal components of the interaxle differential. Inspect the oil filter and the magnetic screen for debris that may indicate damage to the internal components of the clutch for the interaxle differential. Refer to Systems Operation, Testing and Adjusting, "Visual Inspection".