BOSS 3070769 - Caterpillar

Troubleshooting
Note: In the following section, when components are referenced with a number, refer to Illustration 1.Check for any active diagnostic codes for the power train electronic control. Use the built-in electrical diagnostics that are performed with the Computerized Monitoring System and with the electronic control module.Note: This machine is equipped with a power train electronic control. The power train electronic control has a built-in diagnostic system that detects diagnostic codes in the electronic system of the power train.Reference: For additional information on troubleshooting the power train electronic control module (ECM), refer to Service Manual, "Electronic Transmission Control System" for diagnostic procedures for the power train electronic control.Reference: For additional information on troubleshooting the power train electronic control module (ECM), refer to Service Manual, "Caterpillar Monitoring System" for diagnostic procedures.Probable Causes of Transmission Problems
Problem: The transmission does not operate in any speed or the transmission slips in all speeds.Probable causes:
The fuse for the power train control is missing or broken.
There is a problem in the electrical circuit.
Oil pressure is low. This may be caused by any of the following conditions:
Oil level is low.
The oil strainer is dirty. The oil flow circuit has a restriction.
Oil pump failure.
Air leaks on the inlet side of the pump.
There is leakage inside the transmission. The seals around the clutch piston are worn.
Torque converter inlet relief valve (6) is stuck open.
There is a torque converter failure.
There is a mechanical failure in the transmission.
Clutch discs and clutch plates are excessively worn.
The torque converter impeller clutch is not engaged. Problem: The transmission overheats.Probable causes:
Coolant level in the radiator is low.
The machine is being used for the wrong application. There is too much torque converter slip, which is caused by too much load.
Incorrect transmission gear is being used for the load that is on the machine. Shift to a lower gear.
The temperature gauge is faulty.
The oil level is incorrectly high or low.
The oil cooler or oil lines are restricted.
The clutch slips too much. This may be caused by any of the following conditions:
Low oil pressure. Refer to the Problem: The transmission does not operate in any speed or the transmission slips in all speeds.
A clutch is damaged.
Oil flow is low. This may be caused by pump wear or by leakage in the hydraulic system.
There is air in the oil. This may be caused by air leaks on the intake side of the pump.
The magnetic screen for the pump inlet is plugged.
Torque converter inlet relief valve (6) is stuck open. This causes low oil flow through the torque converter.
The clutch or clutches are not fully released. (This is called clutch drag.) This may be caused by any of the following conditions:
Plates warped or discs warped.
The return spring is broken. The return spring is weak. Problem: Pump noise that is not heard normally.Probable causes:
A loud noise at short intervals indicates that foreign material is in the transmission hydraulic system.
A constant loud noise indicates pump failure.
There is air at the inlet side of the pump. Problem: Noise in the transmission that