Wheel Bearing Temperature

[honda03842]

Today we drove from Sutherlin to Silverton, OR, about 150 miles. WHen we arrived I grabbed my infra-red thermometer, removed the hub caps and measured the trailer tire and trailer wheel hub temperatures, primarily becaus I had never done it before.

Both the tires and hubs were about 85F give or take a couple of degrees. The ambient temperature while driving was in the mid 60s.

Has anyone taken similar measurements. To me they seemed OK, particularly because they were virtually the same from side to side.

[Darwin Maring]

We do the same thing, the same way using a Harbor Freight infra-red thermometer and the IR thing works extremely well. You will see a higher reading on the tire temp on the side where the sun shines on both the camper and truck. A well worth unit to have and you can find them when they have a special sale for $35 or less.

I also have radio sending units on the valve stems of the camper and the truck. I can read them on a receiver in the truck and the units will send a Warning should the air pressure goes down 2 lbs or if the tire heats up. They work really well and contrary to what others on this forum have stated in the past, they DO NOT leak air out of the tire.

[Eddie Longest]

Darwin is right on, the tires get hotter on the sunny side. I have used a IR thermometer for about 6 years. 10 -15 degrees above ambient temp. is a good rule of thumb. It seems the spread is more with higher ambient temps. My highest reading was on the sunny side of my trailer with an abient temp of 98F the hubs read 118F running 65mph on the interstate.
Eddie

[honda03842]

Eddie, so it seems you get about 20F above ambient. That's similar to what I read.

Darwin, I also have sending units on my trailer valve stems and it's reassuring to know about the temp and pressure back there but I had never checked the hub.

Normally I see a difference from sun side to shadow side, though most of the driving day they were both in shadow.

[Eddie Longest]

Norm
I do most of my camping in the fall, winter and spring when the temp. is usually below 85F and the differance is usually 10-15 degrees above ambient. The time I did check the temp. when the ambient was in the high 90s I did see about a 20 degree increase. When towing in the winter around freezing the diff. is usually only about a 5-10 deg. increase. I guess you can say the diff. increases as the as the ambient temp. increases.
But the old stand by rule still applies if you can't touch the hub for a couple of seconds after towing for a while you need to check out your bearings or lighten the load on your trailer.
Eddie

[honda03842]

We haven't seen any thing above the 70s since we reached the NW last April but once we hit th mid-West and some higher temps I'll take another reading of the bearings to see how they behave at warmer temps.

[Daniel A.]

I did a 200 mile run with my trailer and pulled into a rest stop checked the wheels just touching the hub.
One side was cool the other it was ten minutes before I could touch it.
I quickly ruled out the bearings as I had an issue with the brakes grabbing when I hooked up.
Once home I decided to check and pulled the wheels, driver side brake had been dragging not releasing properly and given that cob webs were in the housing of the other side it was not working.
In the end I replaced the complete brake assemblies with never adjust Dexter and replaced the hubs as the seals were gone anyway.
I could have just put new seals and other parts in but looking at the complete assemblies that were on I figure a small investment to bring everything back to new was better.
The bearings looked good no signs of heat.

The point is heat could also be brakes.

[Raz]

I am unable to take hub temperature measurements. My trailer came with alloy wheels. They are aesthetically pleasing and bolted right to the brake drum they serve as a wonderful heat sink. Thus, a catch 22. To measure the hub temperature I would need to remove the wheel. But to remove the wheel I must let it cool off.

[Darwin Maring]

When using your hand as a thermometer, use the back of the hand/fingers as it is many more times sensitive than the palm side but DO NOT let it touch what you are checking so you will not get burnt. All U have to do is get close. Try it to believe it.

Daniel: You did the right thing. The labor is the really hard part so going the extra mile will save you in the long run.

Here is a site where you can get an inexpensive IR Thermometer.

Digital InfraRed Thermometer with Laser Sight - Random Color (-32'C~380'C/26'F~716'F) - Worldwide Free Shipping - DX

[Darwin Maring]

Raz, Aim the IR Thermometer at the middle of the cap and if there is a significant difference in temp between the other side and/or the temp of the tow vehicle hubs you may have a problem.

[Carol H]

Originally Posted by Darwin Maring

When using your hand as a thermometer, use the back of the hand/fingers as it is many more times sensitive than the palm side but DO NOT let it touch what you are checking so you will not get burnt. All U have to do is get close. Try it to believe it.

Thats how I do it when I stop for gas. After doing it a few times you soon get to know what the norm is vs the feel of to much heat that goes with something not being right. In my experience if all is good you should actually be able to comfortable put your hand over the cap, if something isnt right you will not be able to comfortable putting your hand on the cap and you will probable feel the extra heat before you do that & burn yourself ;-))

[Bruce H]

I check my trailer wheel and hub temps by feel at every gas or rest stop. I have experienced too many problems and I like to intercept them before they become full blown failures. You soon learn what a normal warm feels like. If one of them is hot figure out what the problem is before you go back out on the road. Most of the time a hot hub is either a bearing failing or a stuck brake. The exception is if you applied the trailer brakes hard when slowing for your stop. That will heat them up.