Any help on keeping these on the hubs. I have to tap them back on every 50 to 100 miles. I have replaced them, theu go on tight. help

Is it all hubs or one in particular?

maybe try applyng a bead of orange RTV silicone around the lip of the bearing buddy before you tap it in. clean both surfaces with brake clean to get any grease off before you apply the RTV.

I have seen when you have a out of balance tire or the bearings get loose, this will happen..

May be applying too much grease and forcing the cap off .

Might need to replace those BB's, as they eventually lose their sealing capability after being taken off/on several times to re-pack your wheel bearings.

BB makes a stainless steel version and they're a bit more durable and won't wallow out their edge so quickly as the standard steel version.

just curious. why would you want to remove them to pack your bearings?
isn't that the purpose of having them on?

Most boat/trailer mfr's recommend you re-pack your trailer bearings at least every three to five years, regardless of Bearing Buddy application.

Some folks re-pack every single year, overkill in my opinion.

Ongoing pumping of grease into BB's is a common problem for blowing out rear seals in trailer hubs...too much grease with nowhere to go!

When you blow out the rear seals, water intrusion and bearing failure is likely.

Re-packing every few years allows you to clean the bearings of old grease, re-pack with new grease, and inspect bearing and race condition (pitting, rust, grooves, etc), thus allowing preventative maintenance BEFORE you're left stranded on the side of the road.

could possibly see the good in that.
BB's used correctly should keep ya from overfilling and blowing the seals,but i would imagine there are some who might just put too much in.
usually repack mine whenever pads are needed,but i put a lot of miles on the trailer.

you might try a light sand blasting on just the lip,it will raise the surface of the lip plus give it a rough texture

This may be a dumb question.......but when was the last time you repacked or checked your wheel bearings? (other than tapping a bearing buddy on and pumping it full of grease)
I have heard of the cotter pin coming out and the spindle nut backing up, causing the bearing buddy not to seat correctly.

lonestar also makes a good point, more isn't always better.

Just somethings you might want to check before getting out the sand blaster...........