I tried the Kopflex KSG coupling grease but it was too thin and exited the coupling very quickly.
To describe the coupling, it is simply an SAE flange mount hydraulic pump. It has a DIN 35-40mm spline input shaft. It spins at up to 2300 rpm and transmits roughly 75-90 horsepower max (average 30ish). Opposite tbe splined end has a cavity with roughly the capacity for half a tube of grease and a plug There are no seals on the splined end. The coupling came from the mfg with what I'm guessing was Kopflex Waverly Torque or a similar moly based product. The datasheet specifically warns against use in high speed couplings. The issue I have is severe fretting wear. I have confirmed all of my dimensions met the requirements of the particular SAE flange mount. I did find the OE coupling to be quite soft, 37C, so I had some produced at 45-48C. The pump shaft is 55C. I am just now putting the harder couplings into service and want to make sure they're protected.
My ultimate goal is to find a grease that reliably provides 1 year of service (3000 hours) without significant wear of the pump shaft or coupling and without relubrication. Better would be to provide 30,000 hours of service because that's when we overhaul, anyways. Mobilgrease 28 has been a great improvement over any other products but I'd like just a bit more performance. I have found Huskey has a full line of polymer thickened greases (kind of like that Falk and Kopflex grease) in NGLI 2. I plan to contact them but am just trolling here for some insight first.
The Molykote pastry lubes are an interesting thought but it seems like the failure would be too rapid if the past lube fails. This component is critical to safe operation of our vessel.