Axle temperature question.

The hub getting hot I would say
Possibly a bearing getting ready to fail,
Dragging brake, caused by a slack adjuster perhaps adjusted up to tightly or another issue in the foundation brake.

is differential low on oil?. That would cause a wheel end to get hot. But also the whole differential to get hot.

Front hub if not slinging oil from hub oil cap has to be leaking at the axle seal. Have you cleaned the breather hole in the middle of the rubber plug. If plugged will cause excess pressure to build in hub and push oil out of seal.

 

everything this guy says.
Start with checking for oil at fill hole. Any leaks under that rear? The hubs should be pretty hot. On some long drives. My forward drive can be pretty close to my manual trans temp on long drives. I have gauges for all those temps. So we are talking close to 150 degrees.
Pick up a heat gun and shoot all your hubs after next trip and shoot the middle of the rears. Cheap temp gun should be in your tool box

 

Shoot your drums or discs too just to rule out a dragging brake.

 

Breather holes in the center of rubber plug.

 

Can you find a place to pull over with little traffic, so you can use your Jakes to come to a stop? Then get out and touch them.

Only one side on two different axles sure seems more like a brake problem than a bearing problem.

 

Breather is on the axle housing, somewhere on top. Either looks like a button or has a vent hose attached to it that points down. Axle housing and hubs are all 1 common housing.

 

Pull the plug turn it over. Use a straight pin or a needle. There is a small hole in the center of that little bump on front side.