They cant hurt but I seriously doubt they do any good. There are 2 bearings in
there. The "buddy" does a good job on the front one but the back one needs it
too. Unless you blow the seal (not good) and force the grease all the way
through, your not getting it to the rear bearing. Having them re-packed each
year is the best advice. If you truely want to eliminate 99% the problems and
maintenance associated with regular bearings, replace them with oil filled
hubs. You can get these at West Marine. No more problems then.