My boat probably gets dunked in the water about 30-40 times (x2 for in and out) per year so that means I have about 40 trips in in the past two seasons. I have bearing buddies and give them a squirt or two a couple times per year. I look for leaks or anything unusual as well as feel the hubs after traveling for excess heat. Total mileage per year is in the 1000's. How often should I have the bearings repacked on my double axle bunk? Thoughts?
push the outside edge of the bearing buddy zerk/plate and make sure it "wobbles" - tellin you it's holding a light pressure of grease. If when you grease it the plate has worked it's way all the way back and isn't "plump" with grease then that tells you your grease wasn't pushing out - and that allows water to get IN.
Also never put so much in that the plate comes all the way forward and jams into the front - because that allows the grease pressure to blow out the seals.
Bottom line - try to keep the spring functioning as a constant "pressurizer" by keeping the zerk/plate position about half way fore/back by greasing often enough to keep it there - since that is how the bearing buddy was designed to function.
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Also - after a while your plate seals in the buddy will get crappy and the buddy will lose pressure after just a few weeks and your always having to scrape a tablespoon of grease out of the hole... that's when you install a new set of buddies (or at least the zerk/plate portion) so that it keeps pressure longer.
Mine lasted about 10 years - then I had to replace the buddies. When I replaced the buddies I replaced the back bearing seals and re-packed the bearings (that were in great condition).