COVER-ROCKER ARM 9Y0015 - Caterpillar

Illustration 1 g02182227
(1) Top ring
(2) Intermediate ring
(3) Oil control ring
(4) Piston pin bore
(5) Piston pin
(6) Piston pin retainer The piston is a two-piece, articulated design. The piston consists of a forged, steel crown and a cast, aluminum skirt. The two pieces of the piston assembly are connected to the piston pin. The two pieces of the piston assembly pivot about the piston pin. The steel crown carries all three piston rings. Oil from the piston cooling jets flows through a chamber which is located directly behind the rings. The oil cools the piston which improves the life of the rings. The pistons have three rings which include two compression rings and one oil ring. All the rings are located above the piston pin bore. The oil ring is a standard ring. Oil returns to the crankcase through holes in the oil ring groove.The connecting rod has a taper on the pin bore end. This taper gives the rod and the piston more strength in the areas with the most load. Four bolts, which are set at a small angle, hold the rod cap to the rod. The design keeps the rod width to a minimum. A larger rod bearing is used and the rod can still be removed through the liner.