Replacement seals for John Deere 790 Excavator and 792 Feller Buncher rotary manifold (center joint / swivel joint) NOT FOR 790D OR 790E , this is the rotary joint in the center of the undercarriage that supplies oil to the travel motors. 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, 3 retaining bolts, bearing plate, lower bearing balls, then push the spindle straight down out of the housing. If you do not do this the upper 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. 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 lower bearing balls, bearing plate, retaining bolts, o-ring & cover. We are Fox Machine, Inc.