For trailer hubs at about $35 a pair would have to be your trailers first accessory. You remove existing dust covers by tapping around the outside of it, to work it off.
The left side is the outside showing grease nipple with dust cap. The right is the inside showing nut that retains nipple, dust cap fitted.
Tap on Bearing Buddie in place by using a lump of timber to seat it in. Fill with grease gun, and its done.
How they work is the cap is spring loaded with a grease nipple in it. As the grease is worked and broken down the spring loaded cap squeezes fresh grease into the bearings. Enhancing the life of your bearings and less maintenance in regular repacking. When the grease in the Buddy becomes low you will see that the cap has sunken down. Simply get the grease gun out to refill.
Rubber cover that come with the set I brought.
The cover that was on my trailer fitted nicely over the top. Come to think of it, why wouldn’t I have a set on the box trailer ? Bearing maintenance like anything in salt is important and multiplied.
Update April 2021
Topping up bearing grease after 7 months and found bearing buddies nipple in the first one loose and its mate laying in the cover. Unable to put it back in. I brought another set to replace them.
On close inspection I found why I was unable to screw the old hubs nipple back into buddy. With a couple of small sockets I found one of these loose, so I nipped them both up ready to change out. I will be able to salvage the old set and probably use on my box trailer.
Update January 2023
I found some info a few months ago and pulled this page until I get this straightened out.
Water Craft Zone had a article on this subject the bottom line is IF your trailer has Marine Bearings installed they will NOT be suitable to have Buddies fitted. Marine Bearings come with a triple lip seal when compressed with grease will lift allowing water contamination. The standard car bearings have a single lip and when compressed seals firmer. I have now installed standard car SKF bearings. Link to full story.
PS: I had found the grease nipple off again after a firm tightening ? Will now use loctite on them.
Jet Ski North Queensland 