BUSHING 3S1292 - Caterpillar

3408, 3408B, 3412 Engines In All ApplicationsSUPPLEMENT: 04/09/90SERVICE MAGAZINE; FEBRUARY 26, 1990; PAGE 12; "Improved Head Gasket Used; Service Tips" in 3408, 3408B, 3412 Engines In All Applications.Disregard the last paragraph in the left hand column. Disregard the illustration in the upper right hand column and the NOTE just after it. On Page 13, disregard the last sentence in the first paragraph under "Retightening Head Bolts." And in the second paragraph in the same section, change 2W9784 to 2W7984.
--------------- END SUPPLEMENT ---------------Reference: Service Magazines: November 14, 1988; Page 7; "New Liner Seat Insert Available" for 3400 Family Of Engines equipped with spacer plates.
January 30, 1989; Page 10; "New Head Gasket Available (Used); Head Gasket Replacement Guidelines" for 3406 Family Of Engines.
August 21, 1989; Page 5; "Improved Head Gasket Used; Summary Of Earlier Gaskets And Service Tips" for 3406, 3406B Family of Engines.
Reference: Guidelines For Reusable Parts, SEBF8131, "Spacer Plates For 3406 Family Of Engines."Description of Change: A new 7E7308 Cylinder Head Gasket is used on 3408/3408B Engines and a new 7E7312 Cylinder Head Gasket is used on 3412 Engines in all applications. The new gasket has the following improvements over the former gaskets. ...A thicker fire ring to compensate for the asbestos-free body material. The thicker fire ring and thinner wrap help to prevent leakage of combustion gases, and give a better "crush" on the liner flange when the head is tightened.
...The overlap of the stainless steel fire ring wrap is reduced to give better gasket body loading and minimize the possibility of fluid leaks. The wrap has a tab-style design. This tab design results in a more flexible gasket that requires extra care in handling and storage.
...The rear and front edges of the gasket body are filled with gasket material between the bolt holes to give more support to the fire rings at both ends of the gasket. See illustration.
Locations of the filled-in ends on the new gasket. 7E6000 Gasket for 3406B Engine shown. The added material shown at both ends also makes it possible to identify (from the outside of the engine) the new 7E7308/7E7312 Gaskets from the former 2W7984/2W7985 Gaskets, respectively....This gasket is NOT coated on the cylinder head side. It DOES have a single layer of black Teflon® (PTFE) on the spacer plate side. The PTFE prevents sticking to the aluminum spacer plate.
Adaptable To: The new 7E7308 Gasket is a direct replacement for the former 2W7984 Gasket which has been canceled. The new 7E7308 Gasket is effective with the following engine serial numbers. 3408B Vehicular Engine: 48W293833408B Truck Engine: 28V48373408 Industrial Engine: 67U132263408B Industrial Engine: 6NB7413408B Generator Set Engine: 78Z35923408B Marine Engine: 99U6595The new 7E7312 Gasket is a direct replacement for the former 2W7985 Gasket which has been canceled. The new 7E7312 Gasket is effective with the following engine serial numbers.
3412 Vehicular Engine: 73W112803412 Industrial Engine: 38S146233412 Industrial Engine: 7DB4983412 Marine Engine: 60M40563412 Generator Set Engine: 81Z9356 Any time the new head gasket is to be installed, refer to the following topics so that