I recently serviced this vintage Seiko Grand Seiko (GS) Hi-Beat (36000) model 4520-8000 for ClockSavant customer and fellow Instagrammer @haibito, the second of two watches he recently sent for servicing. Looking at the movement once the case back was removed, you would have never imagined the amount of dirt that existed inside the movement on the pivots and wheels. This typically happens when someone adds oil to the movement without cleaning and disassembling it. You cannot add oil to a watch that has not been fully disassembled and cleaned and get a good long-term result. Simply adding oil to a dirty watch will result in dirt mixing with the oil and producing more gunk. I had to clean much of the movement by-hand prior to putting it in the cleaning machine. This adds more time than you might think, it took me about 2 hours to clean each of the parts by-hand multiple times as-required. After servicing the watch is running very nicely once again and is a beautiful example of a vintage Grand Seiko.