Denis,denis barden wrote: ↑Mon Mar 07, 2022 5:41 pmBearing Buddies IMO are the same as Shiney Lures and Braid=Wank
Ive had them before and thay leak salt water in over time where as a correctly fitted cap doesnt-The grease inside is designed to melt when warm and lubricate the bearing-No need for full grease under pressure from a bearing buddy.
I'm afraid I've got the Wank factor
Seriously though the principle of the Bearing Buddies makes a lot of sense to me, and it should not be possible for water to enter if they are used PROPERLY, no matter how much time passes. It's all about positive pressure. If you have an inflated football, stick a small needle in it, and push it underwater, what happens ??? You see air bubbles leaking out. You do not get water going through the pin hole and into the football. With Bearing Buddies the most important thing is checking the spring is loaded up just before launching the boat. Due to the spring pressure, the bearing housing is then under positive pressure so it should literally be impossible for water to enter when the pressure inside the bearing housing is greater than the water pressure outside. The trailer hub would have to go deep enough so the water pressure was greater than the pressure inside the hub for any water to get in. Personally I like the idea of the spring being compressed more rather than less, as more spring compression means more force and thus more positive pressure.
With Bearing Buddies the hub is supposed to be completely filled with grease. Any included air is supposed to gradually make it way out when it finds an exit (such as where the Bearing Buddy is pressed into the hub, air can gradually get out but the gap is too thin for the grease to squeeze through). As any air makes it's way out, the spring will extend until it bottoms out, then you no longer have positive internal pressure. That's when water could get in especially if warm hubs are suddenly submerged, the hub cools, the grease & any air contracts, and there may even develop a slightly negative pressure that can suck water in. That's why they need to be regularly checked to ensure the spring is compressed.
I'd bet there's not a great deal of users would take a grease gun with them and if necessary pump some grease in the Bearing Buddies just before launching. I check my Bearing Buddy springs are loaded up just before leaving home, then I check again just before putting the trailer in the water.
I'm a mechanical fitter and did not like the idea of hubs being completely filled with grease. Sealed bearings for instance are never fully packed with grease, maybe half filled and the rest is air. However, the rotational speed of wheel hubs is probably not too fast to cause heating issues due to churning the grease around. I've recently installed new bearings, seals and Bearing Buddies and totally packed the hubs with zero air. Half an hour run at 100 Ks on a hot day and the hubs were only tepid.
