SHAFT 1766997 - Caterpillar

3516 (25Z, 27Z, 29Z) Marine, Industrial And Generator Set EnginesDescription of Change: A new watercooled exhaust manifold is used on the right hand side of high speed 3516 Engines. The new manifold is 300 mm (11.8") longer to reduce residual stresses near the rear end. Residual stresses in the former manifold caused some manifolds to crack. Bellows assemblies are now used to connect the turbochargers to the exhaust manifold. The bellows assemblies will seal under a wide variety of conditions. The former couplings and metal ring seals could become misaligned, causing wear in the exhaust elbow and turbocharger exhaust adapters. The misalignment could also cause exhaust gas leakage.
Because the right hand turbocharger was moved to the rear, a new exhaust elbow is used. Also, the RH air cleaner is moved 300 mm (11.8") to the rear. The exhaust elbow outlet remains in the same location.
A parts service exhaust elbow is available to adapt the bellows assemblies to the former RH exhaust manifold, which is shorter.
Retainers have been added to both air pipes between the turbocharger and aftercooler to provide positive retention for the pipes in the turbocharger housing.
Adaptable To: The new 7C9236 Exhaust Manifold Assembly, 7C9234 Bellows Assembly and 7C9922 Exhaust Elbow are effective with 29Z858 on the 3516 Marine Engines. The new manifold replaces the former 4W1695 Exhaust Manifold Assembly and the new exhaust elbow replaces the former 1W5532 Exhaust Elbow when all the parts are used together as shown in Chart A. The new parts shown in Chart A are adaptable to earlier 3516 Marine Engines and also to 3516 Industrial Engines (27Z) and 3516 Generator Set Engines (25Z) when equipped with watercooled exhaust manifolds.
Illustrations 1, 2, 3 and 4 show the locations of the new parts in the exhaust manifold group, the air lines group, the turbocharger group, and the turbocharger oil lines group.
Illustration 1. New parts for the exhaust manifold group.
Illustration 2. New parts for the air lines group.
Illustration 3. New parts for the turbocharger group.
Illustration 4. New parts for the turbocharger oil lines group.The new 7C9923 Exhaust Elbow can be used with the 7C9234 Bellows Assemblies for parts service on all earlier 3516 Engines which are equipped with the shorter watercooled exhaust manifold on the right hand side. Chart B shows the new and former parts when adapting only the parts service exhaust elbow and the bellows assembly to the above engines.