Cummins Piston & Rings, .040, 4089977

1.00mm oversized Piston Kit
replaces: 4089977, 3966676

Kit includes:1 qty 3949842 Piston2 qty 3901706 Piston Pin Retainer1 qty 3934047 Piston Pin1 qty 4089182 Piston Ring Set
Our pistons are manufactured from special materials like eutectic aluminum, ductile iron and steel alloy. Surface treatments such as anodizing and nitriding are typically used in the ring grooves and crown area for durability. Anti-friction coatings like tinning, phosphate and graphite provide scuff protection during initial engine break in. HDP pistons are designed and manufactured to meet or exceed the most rigorous and stringent specifications.