The John Deere R77667 Piston is an authentic OEM component designed for specific John Deere engines, including those found in tractors and power units. This piston is crucial for the engine's combustion process, providing reliable and efficient operation. Manufactured to John Deere's stringent quality standards, it ensures precise fitment and durability, contributing to the longevity and performance of the engine. It is compatible with models such as the 4040, 4240, 4440, 4640, 4840, 8430, 8630, 8440, 8640, 4050, 4250, 4450, 4650, 4850, 8450, 8650, 4055, 4255, 4455, 4555, 4755, 4955, 4560, 4760, 4960, 8560, 8760, 8960, 8570, 8770, 8870, 8970, 9100, 9200, 9300, 9400, 9120, 9220, 9320, 9420, 9520, 9620, 9330, 9430, 9530, 9630, 9410R, 9460R, 9510R, 9560R, 9470R, 9520R, 9570R, 9620R, 9470RT, 9520RT, 9570RT, 9620RT, 9470RX, 9520RX, 9570RX, and 9620RX.