Mine is running 190-196 on the highway at 70 with the cruise set and OAT's in the low 50's. Is that in line with others? It's freaking me out now because it revved up between the 1-2 shift tonight.

Also asking because the 06 Duramax I had ran 165-170 unless it was in the 90's and I was driving in heavy stop-and-go traffic.

 

Sounds normal. I was at 192 coming home from work at 4am yesterday. Air temp was 23F.

 

I wonder if if has anything to do with the gas v.s. diesel. I have a big block with the allison, and the trans temp runs noticeably warmer than on my duramax.

 

Mine runs 190-198 pretty consistently. Had it since May so I've ran it through the summer months too. Even pulling my Kubota up hills (About 5,000 lbs+trailer,) it never went over 198. Takes a while to get up to temp lately, been in the 20's and 30's lately here in PA.

 

Mine runs 190-195 pulling something or not.

 

Everytime I've checked its running at 198 on the nuts. I have yet to pull anything so the temps are with no extra loads on the truck. Note: just on my second tank of gas.

 

I know this question was asked awhile ago but I have some new data.

I just returned from a 700 mile trip pulling my 30ft 5th wheel. (approx 10,000 lbs) and I had the following transmission temps.

Transmission takes at least 5 miles to get up to 165-175 degrees.
Transmission temperature ranged between 184 – 199 degrees during my trip.
The higher temps were climbing large hills at highway speeds of 55-65 mph.

Some interesting facts were that the transmission temp did not rise when climbing and transmission kicked down to 5th or even 4th gear. That just shows that the cooling system is good. Oh outside temps were between 80 and 85 degrees during climbing. I live in Arizona.

So in conclusion the 189-199 degree transmission temps are normal range.

 

My temps run between 189 to 198.

However, towing my trailer in heavy traffic stop and go, I can get it to reach 210. I've had it touch 214.

 

I just finished a long run with my trialer (2,800 miles) and my temp ranged from 189 on the low end and have gotten it up in the 208 range heavy pulling up hills once. Th outside temp. was over 90 degrees.

Average running flat towing was 189-192 degrees.