Usage:
3406B (7FB) Truck Engines
Description of Change: A new fuel injection pump retaining bushing with a phosphate coating is now used on the above engines. The phosphate coating has a built-in lubricating quality that reduces friction. The coating will help maintain a constant load on the components at assembly. Previously, inadequate joint loading caused fretting on the surfaces between the bonnet and the plunger assembly. See illustration.
Location of components.
Adaptable To: The new 7C6617 Bushing is a direct replacement for the former 8N656 Bushing. The new 7C6617 Bushing can be identified by its charcoal black color. The former 8N656 Bushing had a gold color. Torque specifications for the new bushing is 230 ± 15 N·m (170 ± 10 lb. ft.), compared to 215 ± 15 m (160 ± 10 lb. ft.) for the former part.