Replacement seals for JD Excavator rotary manifolds (center joint / swivel joint), this is the rotary joint in the center of the undercarriage that supplies oil to the travel motors. Fits these John Deere models. 290D 490D 590D 690D 790D 792DLC 892DLC. For manifold as shown with 20 bearing balls model HCJ-090A, if your center joint has only 18 bearing balls you need this seal kit. Damage to the spool when disassembling the center joint, make sure you hold the housing vertically, upside down (cover with model number tag up) remove the cover, o-ring, snap ring & washer, then push the spindle straight down out of the housing. If you do not do this the bearing balls will drag across some of the sealing surfaces causing expensive damage to the spindle. Do not lay it on its side or push the housing down off the spindle. The balls are an interference fit on the top surface of the spindle so there will be damage there and on the housing from assembly/disassembly, but as long as it doesn’t extend to the sealing surfaces that is OK. To re-assemble stand the spindle vertically on a flat surface upside down, using a rubber mallet (or preferably a press) push the housing down over the spindle, place the bearing balls on the spindle race just before you run out of room to work. Then re-install the washer & snap ring, o-ring & cover. We are Fox Machine, Inc. Pictures are representative, colors may vary, please call if you need more information. Never attempt to service a pressurized cylinder, or a cylinder connected to a load, never use air or hydraulic pressure to disassemble a cylinder.