Lab test interpretation PPTX 1966559C1 Locking Ring RING, LOCKING, Replaces K261868 ring Fits Case 580K s n J. One New Aftermarket Replacement Locking Ring for Case Construction and Backhoe Loader Equipment This locking ring (also known as a ring nut) is a front differential component used in the front axle assembly of Case (Case International Harvester) backhoe loaders and construction equipment. It secures and retains key differential components within the front axle, maintaining proper preload and alignment in demanding jobsite conditions. Serial Number Note: The product title specifies fitment for the Case 580K beginning with serial number prefix J (JJG series). Verify your machine serial number before ordering to confirm compatibility. Compatible Models Case Backhoe Loaders: 580K (s n prefix J JJG series), 580L, 580M, 580 Super L, 580 Super M Case Construction and Industrial: 580L, 580M, 580 Super L, 580 Super M, 585G, 586G, 588G Case Forklifts: 585G, 586G, 588G Replaces Part Number(s): 1966559C1, K261868 New aftermarket replacement part not remanufactured, not used.