SEAL-OIL 4J4190 - Caterpillar

Transmission Cooling (General Recommendations)Automatic transmissions generate heat due to converter slippage, charging pump losses, and friction in rotating components. The transmission fluid absorbs this heat and an oil cooler is required in order to dissipate the heat. Keeping the oil cool maintains the lubricating properties of the oil. Cooling the oil also allows the transmission to perform properly and extends the life of the transmission components.The engine coolant (antifreeze) and the automatic transmission fluid (ATF or TDTO) absorbs the heat that is generated by the engine and the transmission. The two fluids carry the heat to a heat exchanger (radiator or cooler). The oil or antifreeze will be cooled at the radiator or cooler.See the Transmission Application and Installation Guide, Engine Application and Installation Guide, and refer to Special Publication, SEBU6250, "Caterpillar Machine Fluid Recommendations" for specific transmission drive train oil and engine fluid requirements.Converter CoolingCaterpillar On-Highway Transmissions have lockup clutches that reduce the heat generated by converters in all gears except first gear and reverse. Under normal operating conditions, the transmission will upshift and the transmission will downshift to the proper gear ratio. The transmission will spend most the operating time in the converter lockup clutch mode. The lockup clutch reduces the converter cooling requirements. If the driver selects first gear hold, the lockup clutch is disabled. This mode of operation will result in continuous converter usage. This mode of operation will result in converter slippage and will generate higher heat loads. The following conditions will dictate transmission cooling requirements: application, ambient temperatures, horsepower being transmitted and length of time in converter drive.
Transmissions that are operated in converter drive for an extended time may over heat. In order to achieve optimum operating temperature, additional cooling capacity may be required to avoid damage to the transmission.
Temperature Operating LimitsThe maximum allowable transmission oil temperatures for normal (continuous) and intermittent (testing) conditions are the following:Continuous sump ... 93 °C (200 °F)Continuous converter out ... 121 °C (250 °F)Intermittent sump ... 121 °C (250 °F)Intermittent converter out ... 149 °C (300 °F)Oil Temperature GaugesIf the OEM chooses to use a color coded converter outlet temperature gauge, the following requirements and recommendations apply:Green - Safe zone is below 121 °C (250 °F)Yellow - Caution zone is 121 °C (250 °F) - 149 °C (300 °F)The following requirement applies:Red - Warning zone above 149 °C (300 °F)If the OEM chooses to use a color coded sump temperature gauge, the following recommendations apply: Green - Safe zone is below 93 °C (200 °F)Yellow - Caution zone 93 °C (200 °F) - 121 °C (250 °F)The following requirement applies:Red - Warning zone above 121 °C (250 °F)
Operators may use the Yellow zone on an intermittent basis for short time intervals. Operation above the Red line for short periods of time can result in damage to the oil and the transmission.
Transmission OverheatingIn the unlikely event that the transmission does over heat, the transmission should be shifted to neutral. Also, the engine speed should be elevated to