hot to the touch drop axle, need help!

I have one of my two drop axles very hot to the touch. I am not sure if it is due to a bad wheel seal (mechanic said the inner wheel seal was leaking...but it had oil in it the entire trip) or a bad slack adjuster holding up the brake (this has happened before), or too much pressure applied to the axle from the control. I am definately concerned and would like to address this before it becomes a major issue. However I do not want to throw parts at it. Mechanic months ago said it had a leaking inner wheel seal, but other than old dried crud on the brakes I am not seeing fresh oil (after topping off the hub) and it seems to be holding the oil i put in. I did back off the brakes and it seemed to have been cooler. Then i adjusted the slack adjuster back to the proper setting and the wheel seemed hot again. I was also told that I might be applying too much pressure to the drop axle and that would cause the heat issue, but the problem seems much more noticable on the one axle (both are a noticably hot compared to the other rims/hubs). Any advice before I have a mechanic throw parts at it that likely wont fix it... Also after adjusting the slack back to what i believe to be the proper setting the truck did roll on its own in neutral so i assumed i had the brakes adjusted right(?). I'm leaning towards a bad bearing (wheel does spin), or bad slack adjuster?, or who knows what else.... i'm really not a mehcanic

 

ya thats what i'm trying to avoid. rather just fix whatever the specific problem is. Trying to find a way to narrow down the problem.

 

i dont know if i should laugh or get nervous reading that advice! Hot is a warning before massive problems begin is my montra.

hard part i'm having with the diagnosis is that the wheel in the up position will not spin as its hitting the bottom of my bed. so i have to run around the truck once i put the axle in the up position to quick test it for spin (it does spin... or at least *did spin once i dramatically backed off the slack adjuster.... i have since readjusted it back to where i thought spec should be).

 

"bad brake adj" that is something I had not considered. is that expensive part and difficult to replace? the rim/wheel did seem less hot after i dramatically backed off the slack ...sooo perhaps it readjusted itself back to a problematic adjustment?