YOKE-1550 7I4187 - Caterpillar

3400 Family Of EnginesDescription of Change: A new drain plug which is designed to accept a rubber O-ring seal is used in the oil pan groups. The new plug and O-ring seal are able to withstand the thermal and vibratory effects better than the former plug and gasket. This will allow the new plug and seal to remain tightened to the correct torque under normal operating conditions. The former gasket design was similar to a flat washer consisting of fiber material encased in a copper sheath. The torque on the former drain plug and gasket will normally decrease from thermal cycling, and should be tightened to the specified torque of 70 15 N m (50 10 lb ft) at each oil change.Adaptable To: The new 9X6451 Drain Plug and 619458 (Viton®) O-ring Seal replace the former 1W7573 Drain Plug and 2A3398 Gasket, when used together. However, the new 9X6451 Drain Plug does NOT have a 1/2 inch square drive, and must be tightened to the same torque as the former drain plug. For the effectivity of this change, see the chart. Also available for use with the former 1W7573 Drain Plug is the 5B3265 Gasket (solid copper) which will retain the correct amount of torque, but may not seal well if the mating surface is worn or damaged. Also, galling may result if the 5B3265 Gasket is over-tightened during installation. Lubricate the new 619458 O-ring Seal with the oil being sealed prior to installation.
This illustration shows both locations of the new parts in the oil pan group used in 3406B Truck Engines. Typically, only one new drain plug and O-ring seal are used in the remaining groups. (1) 619458 O-ring Seal. (2) Drain Plug.