BEARING-SPECIAL 1725317 - Caterpillar

3508, 3512, 3516 (Except 25Z, 27Z, 29Z ) Industrial, Marine, And Generator Set EnginesSUPPLEMENT: 11/06/89SERVICE MAGAZINE; SEPTEMBER 19, 1988; PAGE 12; "Bellows-Type Exhaust Seals Used On Water Cooled Turbochargers" on 3508, 3512, 3516 (Except 25Z, 27Z, 29Z) Industrial, Marine, And Generator Set Engines.Gaskets are now used between each of the four new flanges and the turbine housing and exhaust elbow. The illustration should now show that gaskets ARE used where it reads "No Gaskets Used". Also, change Chart A to show that four 7E2940 Gaskets are needed for new parts, and change Chart B to show that two 7E2940 Gaskets and two 7E2943 Gaskets are needed for new parts. The gaskets further help to eliminate exhaust gas leakage at these four connections between the turbine housings and the exhaust elbow inlets.
--------------- END SUPPLEMENT ---------------Description of Change: Bellows-type seals are used in place of the former metal ring seals and couplings on the above engines to connect the water cooled turbochargers to the exhaust elbow. See illustration. [Bellows-type seals and other improvements for the 3516 Engines (25Z, 27Z, 29Z) are announced in the April 25, 1988 Service Magazine, Page 12.] The bellows seals are not as susceptible to minor problems with misalignment.
Assembly of the bellows seals and connecting parts.The former couplings and metal ring seals could become misaligned, causing wear in the exhaust elbow and turbocharger exhaust adapter, resulting in leaking exhaust gases.
Adaptable To: The new bellows seals are in effect with the following engines (other serial numbers are not available): 3508 Marine-96Y8613512 Marine-50Y763, 66Z2763516 Marine-72Z360The new parts, all used together, can be installed on earlier engines with water cooled turbochargers. See Chart A or Chart B as applicable. The former parts are still serviced.