The part is installed longitudinally in the engine block. It operates the valvetrain via tappets, pushrods, and rocker arms, controlling the opening of the intake and exhaust valves and—depending on the engine configuration—the operation of the injectors.
Important: do not confuse part 4004556 with 4004556-20, which some catalogs identify as a different camshaft. To order the correct part, you must compare the number with the engine’s CPL and ESN.
The cam follower lever operates directly with the camshaft. The lever’s roller follows the cam profile and transfers the movement to the valve train.
During replacement, it is also advisable to check: the roller surface; the roller pin; lever side play; bushings and lever shaft; camshaft lobes; for the presence of pitting, scoring, or uneven wear.
In fact, Cummins and suppliers require the ESN and CPL to confirm compatibility prior to sale.