Usage:
3406B/C (3ZJ, 4CK, 5KJ) Truck Engines
The new 1007408 Camshaft Assembly directly replaces the former 7W3797 Camshaft Assembly. The new camshaft assembly uses the 1007409 Camshaft. The camshaft has polished cam lobes to improve the surface finish of the lobes. This improved finish will increase the life of the camshaft and the cam roller followers. See Chart A.
The camshaft drive gear is now pressed on the camshaft at room temperature. The nose or press length on the camshaft has been modified to allow the gear keyslot to engage the key in the camshaft before the press begins. Installing the camshaft gear at room temperature removes the possibility of the hardness of the gear being reduced if the camshaft drive gear was heated incorrectly for assembly. See Chart B.
