Maybe the other three are too loose?

Technically, we're supposed to be using a dial indicator and getting it close to just a few thousandths. Nobody does this. Slightly loose is a lot better than too tight though.

 

I think you are fine. The likelihood wear and load on each wheel is exactly the same is remote. If things are going south, you will see a good deal more than that.

 

Maybe check your brake adjustment. Perhaps that one wheel is braking more than the others.

 

 

I go by... 20 degrees above ambient air temperature...

then add 20 degrees if the Sun shown on one side for an hour or more....

use brakes as little as possible before doing a Temperature reading.

and 30 degrees more does not mean there is an issue... now over 150-160 is a problem... fyi
my opinion.

 

I think the things that make it so hard to nail down are the multitude of different factors affecting hub temperature. For example, what is the normal variation in factory specs, then there is weight load per bearing, small differences in grease penetration, brake shoe drag, differences in magnet strength, etc. I use an infrared at times, but most often if it burns your hand when you touch the wheel something is wrong. If you set it up correctly, attend to your bearings on schedule, and do not run them too tight, my guess is your are fine.

 

I understand all the variables.. retired auto mechanic.aka drum brakes since 1967... Front and Rear

but a sense of simplicity is needed here.. so the above numbers work for me.
trailer towing something since 1983.....

YES,,, if the hub is painful to touch for a second.. there is an issue...

 

I am actually experiencing a similar issue. I noticed one wheel warmer than the rest on my TT. So I checked and adjusted all 4 brakes so they slightly dragged. Went on a 2 hour trip and all seemed fine on trip down. Towed back home and after backing in driveway walked by wheel and could smell what seemed like brake smell. Took temp of all wheels and all were 110 except the suspect wheel again. It was at 140. So today after speaking with my father. He suggested to jack up wheel and apply brake and check to see how much brake is grabbing compared to others. I used my tiny irwin wood clamp to keep slider on brake controller to 3 bars of output to brakes. The wheel that was hot I could not budge. I then checked the rear wheel and I could move it. It took some effort but I could move it none the less. So I backed off the hot wheel brake to achieve same amount of drag when power applied to brakes. It seems even though I adjusted them to what felt all the same that one wheel seems to grab harder than the others. We have a trip in a couple weeks so I will double check with temp gun to see how it does. I may also do a test run to see how it does.

 

This is great creative problem solving...thanks and please keep us updated with what you find!