no oil in wheel hub

Most modern trailers are oil filled. Grease is old skool that no one needs. OP needs to get to a loves to make sure.

 

And since you are in mountain country look for blue haze when you smell burning. That is your early warning.

Then look at the drum surface itself to see if its cracking covered like a danish icing. That means the drum needs to be replaced. Its destroyed essentially.

I quit worrying about hubs in general when they stopped using the rubber cap versions approximately 1998 on, I knew enough to keep a eye on the wheels for splatter that looks like a old 70's paint spinning toy that spins a paper you spray paint on. It goes straight to the outer edges of same.

 

You can actually smell the brakes before there's haze. If you stop for whatever reason before the haze. Like at a traffic light. Or you've reached destination.

I can smell em anyways.

And if it's oil. I can usually smell it when I've stopped. If its the truck.

 

Lots new trailers have grease packed bearings. It's an option, you can spec either or.
I'm sure the OP has grease.

My advice is if you dont know what your looking at and have no clue, take it to someone who does .

 

For something like this, send us a good image. Any time you have a question about components where there might be confusion about hardware, images are critical for getting meaningful responses.

 

You are definitely right on...Many trailers are packed with a synthetic grease that that is actually drawn to to heat. No liquid level will show on the hub sight glass or in the bottom of the grease well. If they were dry of liquid or "soap" type grease...well , you took a fine time to leave me ole wheel""

 

Hendrickson axles with the TireMaxx inflation system use sealed synthetic grease hubs, usually guaranteed for five years.
Mine has the HXL5 hubs, now six years old, still working good.
As it happens, just ten minutes before getting on this forum. I felt my hubs when parked for the night. Most were stone cold, a couple were just slightly warm. That’s after running two hours at 63 mph grossing 137,000 lbs.

 

To add. I stand against each drive wheel in the morning and lean straight over both duals and then look straight down vertically top of brake drum to bottom of brake drum.

What I am looking for is failure of bearings themselves that spit small parts and crushed races or brake pads coming out of the edge of the drums they are in.

 

You have grease packed bearings. No cap, still has plastic window though. Greased bearings must be sealed. That’s why. If you’re worried about them running dry, check backside of axle, look for leaks. They’ll usually only seep, when s seal is bad. Grease holds up good.Check again for heat, just in case. Compare each side of each axle.Air ride trailer, rear brakes work harder, spring ride, front brakes work harder. Keep in mind, when comparing heat levels. You may have a bearing starting to go bad, But grease is and stays good for years.

 

One small note...if you have the new disc brakes...grease seal leakage will show between the rims or to the front...not the back.