Caterpillar 4P-2656 Piston Ring

Cat 4P-2656 is an OEM compression piston ring with a 120.65 mm gage diameter, cataloged as 4P-2656 in Caterpillar's parts catalog. This ring is designed for Caterpillar diesel engines and commonly appears in piston ring packs alongside 4P-2657 and 4P-2658 for certain G-series engines, such as those used in the G3306 family, where the 120.65 mm bore size defines the ring's fitment. CAT’s official parts pages confirm 4P-2656 as a piston ring with the 120.65 mm gage diameter, and cross-reference materials show it alongside related catalog numbers, indicating a shared bore-size family. Replacement sources also list 4P-2656 under the same OEM reference, including the M-4P2656 listing from Interstate-McBee as a direct Caterpillar piston ring counterpart and a compression-ring listing from third-party suppliers. Use this part when your engine requires a 120.65 mm gage diameter piston ring in a CAT ring-pack configuration; verify your engine model and bore compatibility before ordering.