PLUG 1470268 - Caterpillar

3500 Family Of EnginesReference: Service Magazine; January 19, 1987; Page 6; "Fuel Injector Reference For 3500 Family Of Engines".Description of Change: A new one-piece tappet (follower) is now used in the fuel injectors in the 3500 Family of Engines. See illustration. Formerly, the retainer portion of the new tappet was a separate piece from the tappet. Also, the new one-piece tappet assembly uses a spring-loaded pin in place of a bolt to retain the tappet inside the injector body. The new pin design is stronger.
New 9Y2691 Tappet Assembly with the new one-piece tappet and spring-loaded retaining pin.Adaptable To: The new 9Y2691 Tappet Assembly, which includes the new pin, 3J6956 Spring, and ring, can be used as a direct replacement for the former 4W3561 Tappet, retainer, keeper, and bolt in the 11 mm (Type 2) injectors. Part numbers of the injector groups did not change. These part numbers of the Type 2 injector groups are 7C0341, 7C0345, 7C2239, 9Y0052, 9Y1785, 9Y4544, 7C9578, and 7C9576. The 9Y2691 Tappet Assembly is not adaptable to the 10.7 mm injectors (Type 1), which also have a similar one-piece tappet and retainer combination. (See reference article.) The pin and ring in the new tappet assembly are not serviced.