Infrared Thermometer

I would pick up an inexpensive one from an auto shop,40.00$ should get you one good enough for what you need. I work in a calibration lab and the difference now days between an expensive fluke and a cheap one is not more than a few degrees accuracy.

You will find one that is a lot hotter than the others so it's mostly a relative temperature thing.
When I had an issue with a brake dragging, the hubs were all at about 110 and the bad one was at 165~175.

I have an Infrared, but still use my hand on tires and hubs because its faster.

I have found the sun side of the vehicle to be about 10deg warmer.

VTR wrote:


I am told using one can really avert a problem before it happens.

Thoughts

IMHO you were told wrong.

I have gunned thousands of tires at the track when we race. I will tell you right now that the chances of gunning a hub at just the right time before the bearings smoke are slim to none if not impossible. Brakes will add so much heat to the hubs that the temps will be all over the board.

IOW's you are wasting you time.

If it makes you feel good, go for it; but that's all it will do.

With all due respect Turtle, I am in agreement with Scott. If one hub is hotter than the others, then that hub has a problem....brakes, bearing....something. The actual temps are probably irrelevant, but a significant difference between them definitely signifies a problem.

Ron

I look for the difference between tires/hubs. If three are within a few degrees of each other and one is 50 degrees hotter, I've got a potential problem.

The first several times you use it will not tell you much as you are looking for something out of the ordinary. I temp my tires on the sidewall near the tread and rarely will I have a temp over 140. Hubs can be 100-120 if you have not used the brakes much before measuring. For less than $10 you can buy a nice enough one.
All kind of uses and one that will surprise you is to point it straight up on a clear day and see how low of a temp you can get... -30F in the winter which is around 30,000'.

I got one from harbor freight a few years ago for about $30. seems to work well enough. I agree that what you are looking for is one brake, tire, or hub that is significantly different than the others. I was able to diagnose a brake that was not working as well as the other three on a trailer. Had one cold drum and the other three warm and within a few degrees of each other. Besides it's fun to point the thermometer at lots of other things, like the electric heater, extension cords that are overloaded, the dog's belly.....lots of fun uses. It's a neat educational tool also for kids and grandkids.

Gmw, you sold me. I can check my cat when he hasn't moved for hours.