I bought a Harbor Freight trailer and put it together to make a kayak trailer when carrying all four kayaks. Looks like I'll use it mostly when solo as well since it's so much easier than loading into the truck.
In the kit the hubs came caked with some type of blue grease. I'd read where many came with nothing or something that more resembled olive oil. I didn't know the quality of this blue grease so I removed it when putting the trailer together with carb cleaner and repacked with Lucas bearing grease and installed the OEM dust caps back on. Drove it this way on short (less than 20 miles) trips for about a week and a half. Everytime I got somewhere I put my hand on the hub and it was always ambient temp.
Don't intend on backing this trailer down into the water, but just in case it ever happened I order and installed Bearing Buddys. Yesterday was the maiden voyage and I dropped the kids off at school which was about 8 miles and the hub was ever so slightly warm, not so much warm but I could feel it was warmer than ambient temp. About 6 miles to launch and they felt the same.
Trailer sat at launch in 66 deg until 5ish PM and I drove 11 miles home and they were by no means hot, but I could feel a difference. It was only 11 miles. I'd driven more miles at faster speeds with OEM dust caps and couldn't feel a temp change by hand.
Is this something to worry about? Planning a trip to fish and don't want to worry about the hubs the whole way. I KNOW they're packed and there's plenty of grease.