SHAFT 3W4566 - Caterpillar

Problem: The oil level is too low
Probable Cause
There is a leakage in the oil lines. See "Check: Check for oil leakage.". Add oil before you perform any tests.Problem: There is an indication of water in the oil
Probable Cause
Failure of the torque converter oil coolerProblem: There is an indication of air in the oil
Probable Cause
There is a leakage in the oil lines. See "Check: Check for oil leakage.".Problem: Rubber particles are found
Probable Cause
Seal failure
Hose failureProblem: Shiny steel particles are found
Illustration 1 g03028758
(1) Gear pump for the torque converter Probable Cause
Mechanical failure of the torque converter section (1) of the gear pump. See "Check: Check the torque converter oil filter."
Mechanical breakdown of the oil pump drive.Problem: Aluminum particles are found
Probable Cause
Mechanical failure of the torque converter. See "Check: Check the suction screen."Problem: Black fiber is found
Probable Cause
There is a worn lockup clutch in the torque converter. See "Check: Check the suction screen."Check: Check the oil level in the transmission case.
Illustration 2 g03028759
(2) Oil level sight gauge for the transmission Check the oil level in the transmission case. Look for air or water in sight gauge (2). Many problems in the torque converter are caused by low oil level or air in the oil. The transmission oil must be at operating temperature and the transmission must run in NEUTRAL to circulate oil in the lines, cooler, and planetary before an accurate oil level reading can be taken. See the Operation and Maintenance Manual, SEBU8133 for the correct type of oil.Check: Check for oil leakage.
Inspect all oil lines, all hoses, and all connections for damage or for leaks. Look for evidence of an oil leak under the machine.
Illustration 3 g00687600Note: If oil can leak out of a fitting or out of a connection, air can enter the system. Air in the system can be as harmful as having too little oil.Check: Check the torque converter oil filter.
Illustration 4 g03028736
(3) Transmission oil filter
(4) Bypass valve Remove torque converter oil filter (3). Inspect the filter for foreign material.Note: Torque converter oil filter (3) has an oil filter bypass valve (4). Oil filter bypass valve (4) allows oil to bypass the oil filter element whenever the pressure difference between the inlet oil and the outlet oil at the oil filter gets too high. Any oil that does not go through the filter element flows directly into the hydraulic circuit. Unfiltered oil may cause sticking valves and restrictions in valve orifices.The pressure bypass valve (4) in the torque converter oil filter (3) senses the difference in inlet and outlet pressure. The bypass valve (4) is set to open when the differential pressure between inlet and outlet exceeds 520 21 kPa (75 3 psi).Check: Check the suction screen.
Illustration 5 g03028739
(5) Cover for the suction screen Make sure that the oil has been drained from the hydraulic oil tank and from the torque converter for the next check.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared