GUARD AS 4931075 - Caterpillar

Illustration 1 g01293483
Piston assembly
The piston is a one-piece piston that is made of forged steel. A large circumferential slot separates the crown and the skirt. The crown and the skirt remain attached by the strut for the pin bore. The 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. Oil returns to the crankcase through holes in the oil ring groove.
Illustration 2 g01293536
Connecting rod
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. Six bolts, which are set at a small angle, hold the rod cap to the rod. This design keeps the rod width to a minimum, so that a larger rod bearing can be used. The connecting rod, the piston, and the liner must be removed as a group. The connecting rod can not be removed without also removing the liner.The connecting rod is a one-piece forging that is fractured hydraulically in order to split the big end cap from the connecting rod. This process produces a rough surface that is accurately matched on each side for improved strength. The rough surface also prevents lateral movement of the mating surfaces.The caps and the rods must stay together as a pair. The caps and the rods cannot be mixed.The connecting rods are different for each side of the engine. The connecting rods must be installed on the correct side of the engine.