Over the years I have run a number of semi tractors with lots of gauges including both rear axles and tranny temp. None of them were anywhere close to 300*. It's been quite some time since I drove one with full gauges and the current rig I drive occasionally has minimal. So I can't recall where the red line is but I can say fairly confidently I would not be running it very far if I were seeing that type of trans or rear axle temps.

Tranny temps should run 60-80* above ambient air temps...

If its 100 out you should expect to see 160-180*... Towing heavy with the TC unlocked you could see 200-220*

Nothing to get excited about up to about 225* or so, then and only then would I worry about pulling over and leaving the truck running to cool it down (in N or park)

Winter, I will rarely see over 130, Summer I will regularly see 180-190*.

Yes, you can have your tranny too cold and run into issues.

i drive big rig which has over 20 freaking guauges, and i think the rear and front rear and trans run around 180. 300 does sound hot, but the gauge may not be very accurate???

thanks guys

trannie temp
 

Can anyone tell me what the tft_v temp reading is on this tunner all so has a tft reading what i should be looking at transmission

OOOO boy you guys are only getting around 180 degrees on your tranny temp?? Im pushing 200* sometimes. I mean then again I am in cali where it gets pretty hot and pulling a 26ft weekend warrior through some pretty steep grades out towards Glamis. do any of you have any good tips on driving with a load?

Cooler now
 

I run a 22 foot Weekend Warrior with ATV, Dirt Bike, 110 gallons of fresh water, along with more junk than three families need. It's only about 9k lbs but on a 90 degree day my tranny temps were on the higher end of 200 degrees-F. Last year I pulled the stock cooler and put in a 6.0 cooler (almost 3 times larger). The stock cooler was only slightly bigger than my power steering cooler...I couldn't believe it.:dang: Anyway, I pulled my trailer on a 90 Plus day (with A/C running for the wife) and the warmest temperature I saw was 130 to 137 degrees-F. Granted, I wasn't on a big hill but there was an upward grade for a long pull. The extra cooling made a huge difference. :tu: