Heat specs

[Lin]

I am not sure if this has been done, but it seems that it would be useful to have a comprehensive list of the normal heat range of different areas and components.  For example, if I pulled over to fuel up after driving for a while I could have a check list and run around with the IR gun to make sure all is well.  What is the range for tire heat, exhaust manifold heat, wheel hubs, exhaust temp, etc.?  I would think that there must be a few other things that should be on the list too.  Does this make sense?

[cody]

Makes perfect sence to me, I'm a rookie when it comes to all this and just to have a ballpark figure to relate to would be very helpfull, for somebody like me, it could prevent an engine failure that I wouldn't know was coming otherwise.

[Bob Gil]

With all the variables I think each person would have to do this for him self.

There are too many things that change with the direction of the air to the surface that you are driving on and the sun. 

Way too many things to consider.

You would have some thinking they were ok when they were in trouble.  Say I was in Texas at noon in June it would not be any where close to some things in North Dakota in the early evening.

Bob

[tekebird]

lots of variables.

last time I drove my 04 tit had tire pressure and temp sensors on it.

wathching that through a 2000 miles trip was something.

cross winds the lee side had a good 15 degree cooler tire.
dessert sun had a effect from sunny to shaded as well but don't recall what it was off hand.

I think you would find that alot of componenets will have a pretty wide acceptable opperating temp range

[Nick Badame Refrig/ACC]

Hi Lin,


I live by the rule of engine temp... Anything hotter then my engine is not good.  Exhaust manifolds and turbo's can

usually get glowing hot and should not be included in this. Just make sure there are no leaks.

Smoke is a bad warning method too...Lol  I think smoke can happen at 215deg.

Hopefully someone here has the exact science!
Nick-

[Lin]

Nick,
     Glad you make the exception for exhaust manifolds.  You had me worried for a moment.

[bobofthenorth]

I don't think you can come up with a "normal" value for a lot of the IR readings.  I look for the steers and the tags on each side to run about the same temp as well as the towed tires on that side.  Drives will always be a little higher and the inside dual usually is a little higher than the outside.  The sunny side of the rig can be 50 degrees higher than the shady side.  I also check the drive hubs and expect both sides to be the same but the absolute temp can vary depending on ambient and how hard you are pulling.

[JackConrad]

     We look at comparing temps as much as actual temp.  Steering hubs should be close to same reading, steering tires should be close. Tag axle tires shoud be close. Drive axle inner tires should be close, etc. These readins have to take in account sun shing on one side, crosswind, etc. Notice we compare apples to apples, oranges to oranges. Since the different axles carry different loads, we do not compare steering to drive to tag.  There are so many variables that it is very difficult to set a specific temp range. Driving in 30 degree temps will give drastically diffenert reading than driving in 100 degree temps. In bright sun, driving on asphalt will give a slightly hotter reading than driving on concrete. Driving in a city with a lot of stoplights will increase the temps.  Jack

[buswarrior]

Every busnut should have an IR gun! Absolutely top notch trouble shooting tool.

In my fooling around with an IR gun, with the above noted variations for sunshine, after highway running, the tires seem to be anywhere 30 to 40 degrees Fahrenheit above ambient. A little higher when the pavement is hot from the sun, a little cooler on a cloudy day. That's in 2 digit conditions. I haven't run in the desert in summertime yet.

The bearings/wheel ends seem to be a little cooler than the tires, but not by far.

Brake drums all depend on how you used them when pulling in. A brake drum close to ambient with the others well above, or the opposite, is cause for concern for brake balance and function.

A hotter brake drum may have an influence to pull the bearing/wheel end up a little, as well as the tire, as all that stuff is against one another.

Side note: The DOT in a number of jurisdictions are experimenting with IR at roadside, looking at passing vehicles in locations that have required brake use, to see either the hot or cold drums, and then inspecting the ones that are irregular. A mixed blessing for a busnut to get caught up in that, I guess?

On tire temps, the devil is that the inner drive tires are prone to showing a little higher temp under some circumstances, but a tire with low air pressure will also show you a higher temp, and it's inner dual duals that have the reputation, deserved or not, of being the ones that let go out on the road, and a low tire on the dual can't be identified as easily as an outside....

Some form of driver's seat tire pressure monitoring coupled with IR Gun use would leave one at complete ease?

happy coaching!
buswarrior

[Dreamscape]

On our short 500 mile trip to and from TBR in checking the inner dual it was 10-15 degrees cooler. Other posts said it should be warmer. Cooler is better, right?

All tires were set at 100 psi cold.

Depending on which side faced the sun while motoring down the road they ranged from 110-120, ambient was about 80. I think that trying to come with a graph of temps would be impossible, too many variables. The temps on the trip to were a little lower than coming home.

I always check the tires, engine and generator while stopping for a break. These IR guns are one of the most handy devices ever invented by man, I love the darn thing.

FWIW,

Paul

[TomC]

Paul-check your tire pressures when cold (this should be done once a week anyway).  Then let us know if your inners are higher pressure then the outers.  Good Luck, TomC