Process for measuring temps with IR gun

[LCA078]

As I'm learning my new-to-me M923, I want to ensure the operating temps of the engine and tranny are within limits (and my dash gauges are accurate-ish). I'm assuming I can run the truck on a road about 5-10 mins then just take my IR gun and hit the block in multiple places to measure engine temp. Same with the Allison, right? Maybe even run around to the hubs, axles, and brakes to verify nothing is hot? Am I missing anything?

I doubt by the time i get the hood opened I can do useful temp readings on the exhaust header so not asking about EGTs which I'd only be worried about under a good load.

And looks like there's a type in the TM about engine temps... should be 175-195deg I'm assuming.

 

[162tcat]

Unless you have reason to not trust the gauges, your over analyzing it. Checking the hubs is a good idea though. Honestly, it's not a bad idea to repack or at least physically check the wheel bearings.


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[FullSpecial]

If you're going to check your gauges, aim at the base of the temp senders.

 

[LCA078]

Unless you have reason to not trust the gauges, your over analyzing it.

Yeah, I get it's being anal but it's only a five min check for a great peace of mind that i'm not toasting anything- especially since I'm responsible for repairs and not Uncle Sam. I read a few posts about engine temp gauges being off (too high) and freaking out the owner. After I feel good about the gauges I'll probably never worry about them again. And reading the temp near the temp sender to 'gauge the gauge' is a solid idea.

I did see a bit about hitting each cylinder to verify they're balanced. A hot/cold cylinder may mean something to diagnose.

 

[Jbulach]

Wes has general operating temps of just about everything in the parts spread sheet sticky.

 

[CMPPhil]

Gives you some data points to reffer back to

Hi

Though I don't have a 5 Ton I do have three old and heavy MVs, I've been using an IR gun to check a number of points on the truck as part of my post run check. Made up a check page with list wheels, hubs, engine oil pan, radiator transmission, etc. (I'll post my check sheet if anybody is interested.)

When I come back from a long drive I go through the log sheet writing down temp of each point, while the trucks are idling down the list makes me look at the trucks in a systematic look at the trucks. With the sheet showing me what the previous readings right there anything out of line sure sticks out. Interesting some of the things that will jump out at you, one tire hotter than the others low air preassure, hotter or colder brake drum dragging brake or out of adjustment. Transmission, transfere case, pumpkins hotter check the lube level.

So I look at a systematic check as being a health check on the truck.

Cheers Phil

 

[162tcat]

Yeah, I get it's being anal but it's only a five min check for a great peace of mind that i'm not toasting anything- especially since I'm responsible for repairs and not Uncle Sam. I read a few posts about engine temp gauges being off (too high) and freaking out the owner. After I feel good about the gauges I'll probably never worry about them again. And reading the temp near the temp sender to 'gauge the gauge' is a solid idea.

I did see a bit about hitting each cylinder to verify they're balanced. A hot/cold cylinder may mean something to diagnose.

If you want piece of mine, check the wheel bearings and all fluid levels. I'd be far more concerned about that than I would about the engine and trans as long as the fluid levels are normally, gauges are reading within spec and nothing smells funny. Being "anal" with the temp gauge on things won't replace actual maintenance and physical checks. I've seen plenty of loose wheel bearings on RRAD trucks, even found one without the outer lock nut! RRAD was very hit and miss. Lots of trucks with airlines installed incorrectly, poor quality repairs and just plain shotty work. I'd be willing to bet most of them were better off before they went through the RRAD process.


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[Ajax MD]

Where can you shoot the wheel bearings with everything fully assembled? The only place I can think of, is the center of the brake backing plate and possibly the hub center on the outside.

 

[CMPPhil]

Where can you shoot the wheel bearings with everything fully assembled? The only place I can think of, is the center of the brake backing plate and possibly the hub center on the outside.

Hi

What you are looking for is a difference one side to the other, particularly if appears suddenly like one trip to the next. I shoot the outer hub and the swivel ball housing. I didn't follow up once on a 10 degree jump in front hub next trip smoke and with loose hub nut. See http://canadianmilitarypattern.com/How close can you come to loosing a wheel.htm for the rest of the story.

Once you have norms for your truck your looking sudden changes. Of course one of the temps you take is air temp, like the front fenders.

Cheers Phil

 

[LCA078]

I've been using an IR gun to check a number of points on the truck as part of my post run check.

I appreciate the post-run check, especially on older equipment as seals eventually wear out, lubrication oils seep out, grease breakdown, etc. It takes no more than a few seconds to walk around and feel (IR gun) each hub, look for leaks, smell for burning/odd smells, listen for heat crackling/pings, etc. and catch a small service item before it turns into major repair item. Maybe pre- and post-run checks were just beat into me from my time in the service but I do agree they are useful.