I didn't get to the trans shop today, but will try to tomorrow and talk with them about the 1st gear noise.
Did some scanning tonight and the temp gauge is dead accurate. I did see TCC locking up on the scanner.
maybe I need a new cooler or maybe that obnoxious noise is the cause of the heat. The 1st gear noise sounds like a rotor getting turned.

 

Oh! Not what I have. I could not open the videos. The sound of rotors being cut coming from your transmission is very different than your description in the first post of the noise as "noise". If you said that in the first post, I think everyone would have told you to park the truck.

 

Noise is probably cause of the heat or vice versa. I doubt you need a new cooler in this weather lol
that trans is toast.

 

I got down to the shop today and talked to the trans guy. He is going to put a new planetary set in - even he stated it was pretty loud. So, hopefully that will take care of the obnoxious noise. For heat issue, we think it may be a bad temp sensor. Will report after everything gets done. Might be around a week.

 

Just as a point of reference, when I was setting up the transmission temperature gauge in my '96 C3500 when I built it into a wrecker - 20-something years ago - I used an IR temp gun to compare my gauge readings against multiple points all across the transmission. I'd shoot the pan, converter, areas all around the case, etc. easy to see what the hottest temp I could find was since the Fluke I was using (and I suspect many are like this) you can scan all around holding the trigger and it will maintain a "max" reading of the hottest. Actual readings were within 1/2 degrees of the gauge reading. I say all that to offer that you can confirm the transmission temp sender pretty accurately using an IR temp gun.

Richard

 

Pull the dipstick and smell the fluid

 

We did that. There was huge discrepancy, about 60 degrees.


Did that too. It did not smell burned.

 

Your truck has a temperature sensor integrated in the valvebody electrical harness. If I'm seeing your picture correctly, you are using the temperature gauge in your cluster, correct? If so, it should be an accurate reading.

The fact that the fluid doesn't smell burnt is good news...🤞

 

4L80’s have straight cut 1st gears for trucks 8600+ GVWR. Totally normal.

 

Sorry, I didn't follow up on the progress.

The planetaries were all replaced and a new temperature sensor installed in the valve body. So much quieter now in 1st gear. Still a bit of a whine, but very tolerable - radio drowns it out most of the time. New sensor fixed the temp issue, so it now reads correctly.