Cummins ISX11.9 CM2250 – Service Manual 004-999   Cam Followers/Tappets – Overview

There are two identical cam follower assemblies, front assembly for cylinders 1 through 3 and rear assembly for cylinders 4 through 6. The cam follower assemblies are interchangeable and the cam followers are interchangeable as well. These assemblies mount inside the cylinder block.

NOTE: The shaft is not symmetric. The flat end of the shaft must be facing down for correct installation into the cylinder block.

ISX11.9 cam followers are not rebuildable in the field due to the fit between the pin and lever. Liquid nitrogen is required to shrink the pin sufficiently to slide it through the bores in the lever.

Thorough cleaning of the cam follower is difficult after an engine has experienced a dust-out (intake air contamination) or oil contamination from metal debris. Debris left in the cam follower may prevent the roller from rotating, resulting in damage to the camshaft lobe and cam follower. It is recommended to replace the cam followers after an  engine has experienced a dust-out (intake air contamination) or oil contamination from metal debris.