SHAFT AS 3043266 - Caterpillar

3500 Family Of EnginesReference: Service Magazine; October 30, 1989; Page 12; "Exhaust Manifold Gasket Removed From Between Exhaust Sleeve And Manifold Section" for 3500 Family Of Engines; D11N, 776B Tractors; 777B, 785, 789 Trucks.Description of Change: Several changes have been made to the exhaust manifold in the area of the expansion sleeves and bolts. The gasket between the sleeves and the flange on the manifolds has been removed. See the reference article and the illustration.
New 7C4015 Exhaust Manifold Sleeves (made from powdered metal) replaced the former 7N4902 Exhaust Manifold Sleeves (made from cast iron). New 3H6740 Bolts (which are made from a stainless steel alloy) replace the former 5P2755 Bolts. See Chart A for the effective serial numbers for these changes.
A new 8C8491 Washer has been added under the bolt head to eliminate galling of the sleeve surface. The galling could cause a loss of bolt torque. Also, a new 7E2599 Exhaust Manifold Sleeve is used. The new sleeve is slightly thinner than the former sleeve. This will ensure that the new bolt will project completely through the locknut with the additional thickness of the new washer. See Chart B for effective serial numbers for these changes.
Adaptable To: The part numbers for the improved 7C8133, 7C8144, 7C8155, 7N8641, 7N8723, 8N0367, 8N7721, 8N9515, 1W5936, 1W7566, 9Y0020, and 9Y6455 Exhaust Manifold Groups have not changed. The 7C4015 Exhaust Manifold Sleeve and 3H6740 Bolt were direct replacements for the former parts. The 8C8491 Washer and 7E2599 Exhaust Manifold Sleeve are adaptable to first production when used together. See the illustration for the typical location of the new parts.
Location of the new parts. (1) Sleeve. (2) Washer. (3) Bolt. Typical location of the former gasket (arrow).