Bulldog BD-558217 Seal Kit is a genuine Bulldog hydraulic seal kit engineered for the hoist cylinder on the Caterpillar 777D off-highway truck. Bulldog's official catalog lists this BD-558217 kit under the Hoist category for the 777D, with fit notes referencing configurations such as 2YW and 1 UP. In a Bulldog catalog entry, BD-558217 is shown with dimensions listed as 9.500S and 5.500S, a convention used to denote bore and stroke specs in that catalog. This BD-series seal kit sits within Bulldog’s broader lineup of Caterpillar-compatible hydraulic seal kits for truck hoists and other heavy equipment applications.
