Patent ID: 8590987

Claim:
An idler of an undercarriage assembly for a track-type machine, the undercarriage assembly including at least two links interconnected by a pin and a bushing, the bushing being rotatable relative to the pin and the links, wherein at least one of the links includes a link rail wear surface, the link rail wear surface being positioned an original wear surface height from the bushing, the idler comprising: a lower surface configured to initially contact and wear against the link rail wear surface until the at least one of the links including the link rail wear surface wears to a predetermined point, and an upper surface configured to contact and wear against the bushing after the at least one of the links including the link rail wear surface wears to the predetermined point, the upper surface being positioned radially outward of the lower surface by an original upper surface height, wherein the original upper surface height is sized between approximately 70% and approximately 90% of the original wear surface height, such that the upper surface contacts the bushing after the at least one of the links including the link rail wear surface wears to the predetermined point and can continue to contact the bushing until the at least one of the links including the link rail wear surface is approximately 100% worn.