Your search for "trailer bearing" revealed the following:
How to Replace a Trailer Hub, Bearings & Grease Seal
Replacing a trailer hub is straightforward when the spindle is in good condition and the replacement hub actually matches it. The work itself is only half the job. The other half is correctly identifying the bearings, grease seal, bolt pattern, spindle family, hub type, and brake configuration before the old...
GVWR & Trailer Payload Calculator: How Much Can My Trailer Actually Carry?
Two 3,500 lb axles do not automatically make a trailer capable of carrying 7,000 lb of cargo. Trailer capacity involves several different ratings: GVWR, axle capacity, tire capacity, empty weight and the portion of the load carried at the hitch. Enter the numbers you know below. The calculator will show...