Dodge 5.9L Cummins Diesel Cam Gear Retainer. Required for trucks running 13mm injection pumps, also recommended for trucks running high hp with 12mm injection pumps. Prevents the cam gear from "walking" off the cam. This retainer is for cams that are already PRE-DRILLED (or that you will drill and tap) for a retainer. This comes with a 7/16-14 threaded bolt. threaded hole needs to be atleast 1" deep.