GumbyRT,
That will be great information to pass along when you perform those check with the actual tool and the thermo gun.
BTW, I heard the ATF fill-tube portion that hides behind the pan is sort-of long and makes it a pain in the rear to remove and install, unless you know of some sort of trick. So, what I heard another did, was to cut about 1&3/4" off that portion and it speeds up the removal and install tremendously.

 

Not sure what you mean by the portion of the fill tube “behind” the pan - the section that’s inside the valve body cover is only a couple inches long. I actually found the fill tube quite useful for removing and installing the cover, but I probably took a different approach than many.

If I’d of done this at work, I could’ve easily accessed everything from underneath on the hoist; but since I did it at home, I cleared the top side too so I had plenty of room to work. I removed the battery, battery tray, wiring harness (disconnected TIPM, PCM, grounds and a few other connectors then folded it over the intake), and coolant reservoir. I probably didn’t have to do all that but I like having room to work, especially when RTV is involved, and it gave me a chance to inspect the wiring harness as well as clean some grounds that aren’t easily accessible.

I can post my pictures later, but here’s my findings with the laser thermometer. There’s plenty more testing that needs to be done with this - unfortunately I only had about 15 minutes as I needed to get back home, so I didn’t spend as much time checking this as I wanted to.

These were taken after about a 10 mile drive. Once at work I shifted through each gear position a couple of times, pausing for a few seconds in each gear (ensures the trans is as full as possible), then allowed the engine to idle while checking the fluid level. After the fluid level was set correctly, I took readings in a few different places and compared them with live data.

At this point in time, I don’t think there’s enough data to conclusively support or reject the use of a laser thermometer to accurately check the fluid level. Besides not having enough time to be more thorough with the data, the trans wasn’t hot enough for Dodge’s recommended hot check (min 180*F), and the cooling fans did kick on a couple of times and I’m not sure how that may have affected the readings.

Here’s what I found (all temps in Fahrenheit)

Location of Measurement - Laser Temp Reading - Live Data

Front of oil pan - 124.8 - 134.35
Trans Case behind oil pan - 123.4 - 134.54
Bottom of valve body cover - 120.9 - 134.54
Top of valve body cover - 134.7 - 134.54
Trans cooler outlet @ trans - 135.6 - 134.73
Top of case near engine/ID tag (what most would call the bell housing) - 168.4 - 135.12
Fluid on dipstick - 83.8 - 137.03

Obviously the closest to live data was the top of the valve body cover - the most inaccurate was the fluid on the dipstick but I think that’s because the dipstick doesn’t ride in the trans, so it quickly lowers the fluid temp before a reading can be done. A traditional dipstick that rides in the trans would probably read differently, or maybe even leaving the dipstick in the trans for a few minutes to adjust to the fluid temp may matter.

There’s MUCH more data needed on this to be conclusive one way or the other, but if I were in a pinch and needing to check it, I’d be ok with reading the temp on the valve body cover. There’s a safe range of about 18 mm no matter what the temp is once it’s above 100, so that could cover a range of temps as well.