The standard "marine" bearing seal is the root of most bearing problems. Even the so called "terrestrial" seal is better. The best system is oil filled hubs, the "Durahub" system. With oil you can see if you have a problem.
However, a simple solution is to switch the inner seals to the Guest brand. (I have no connection).
The DuraHub oil conversion includes a spring loaded seal "Guest" Brand, No 28560 if you have the "Holden" bearings (40 mm axle shaft). For the "Ford" or "Slimline " bearings it is no 28600. These seals will also work with grease. Add a set of "Bearing Buddies" which are grease nipples for topping up your grease from the hub, and you will have much more reliable wheel bearings.
The Guest and terrestrial seals turn with the hub. The marine type is supposed to be fixed to the axle, but it usually just screws itself out of the hub.
Trailer Wheel Bearings
Trailer Wheel Bearings
Ian B
Ex Investigator 563 #50 Yara
Ex Investigator 563 #50 Yara