TUBE, 94 DIA 1 1044165 - 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 to dissipate the heat. Keeping the oil cool maintains the lubricating properties of the oil, allows the transmission to perform properly, and extends the life of the transmission components.The engine coolant (antifreeze) and the transmission fluid (TDTO) absorb the heat generated by the engine and transmission. The two fluids carry the heat to a heat exchanger (radiator or cooler) where the oil or antifreeze can be cooled.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 Cooling
Caterpillar Railway Transmissions have lockup clutches that reduce the heat generated by converters in all gears. Under normal operating conditions, the transmission will upshift and downshift to the proper gear ratio. Also, the transmission will spend a portion of the operating time in the converter lockup clutch mode. The lockup clutch reduces the converter cooling requirements. This mode of operation will result in less converter slippage and lower heat generation. The application, ambient temperatures, and horsepower being transmitted will dictate transmission cooling requirements.Temperature Operating Limits
The maximum allowable transmission oil temperatures for normal (continuous) and intermittent conditions are the following:Continuous transmission (pump inlet) ... 95 °C (203 °F)Continuous converter out ... 105 °C (221 °F)Intermittent transmission (pump inlet) ... 99 °C (210 °F)Intermittent converter out ... 125 °C (257 °F)Minimum transmission start temperature ... –20 °C (–4 °F)Transmission Overheating
In the unlikely event that the transmission does over heat, the transmission should be shifted to neutral. And the engine speed should be elevated to high idle until the transmission temperature returns to the proper operating temperature. Elevating the engine speed to high idle causes the engine fan to provide the most airflow across the radiator. Also, the higher engine speed maximizes oil flow through the cooler.Bolt Torques
Standard Bolt Torques
Standard torque values are listed in Tables 1 and 2 below. Non-standard (special) torque values are called out in the specifications section of Specifications, System Operation, Testing and Adjusting, RENR9663. The specifications section takes precedence over the standard torque values listed in the tables below.
The torques in the following tables are based on metric Grade 10.9 or higher fasteners (SAE Grade 8 or higher inch fasteners). Use hardened washers. Split lock washers are not permitted.
Table 1
Inch Nuts and Bolts
Thread Size (Inch) Standard Torque
1/4 12 3 N m (9 2 lb ft)
5/16 25 6 N m (18 4 lb ft)
3/8 47 9 N m (35 7 lb ft)
7/16 70 15 N m (52 11 lb ft)
1/2 105 20 N m (77 15 lb ft)
9/16 160 30 N m (118 22 lb ft)
5/8 215 40 N m (159 30 lb ft)
3/4 370