• a. The speed gear pump burns out; the oil level of transmission oil tank is too low or too high; the primary filter screen of the transmission oil sump is blocked or the filter element is blocked; oil supply volume of the oil circuit is so little that the system fails to offer enough fluid flow to release the heat, which then results in over high oil temperature.
• b. The engine belt is loose; air exhaust volume is insufficient; the oil fluid radiation is slow; the water level of water tank is relatively low, or the pipelines in the engine oil cooler break which causes the coolant volume insufficient and the cooling slows down. If oil is found in the water tank, it can be generally concluded that the pipeline of the oil radiator breaks.
• c. Since the fuel supply system is shared by the transmission and the torque converter, if the pressure of each shift in the transmission is too low (less than 0.8MPa), the friction disc of the gear position in the transmission will slip, give out heat, and also cause over high oil temperature.
• Troubleshooting: adjust the transmission pressure to 1.08-1.47MPa.
d. When 24 rollers in the overrunning clutch (two-shaft assembly) are fixed and mechanical friction is generated, the oil temperature may also have a sharp increase though the system pressure is normal.
• Troubleshooting: replace the two-shaft assembly.
• e. The rotary oil seal which is positioned at the mating face of the inner hole of transfer gear and the guide roller seat is damaged; the large amount of operating oil is leaking inside the torque converter and directly flows back to the oil sump (inside the transmission), which will also cause a sharp increase in oil temperature of the torque converter.
• Troubleshooting: replace the rotary oil seal.
• f. Improper operation, too frequent engine throttle increase, long-time overload operation of the loader, or excessive time of operation under braking condition which may also lead to drastic increase in oil temperature.