Proper transmission temp

[turbows6]

Just got my car on the road after doing a bunch of stuff and putting a new transmission in. I am running through the stock transmission cooler into one of the larger B&M stacked plate type coolers, and even after driving the car for 30 minutes the transmission temperature only gets up to about 110-120* (It was only in the 50's outside though) Is that too low? I know a lot of people say 160 is good, and every 20* drop will practically double the life of the transmission, but I know there has to be a limit or point when it's running too cool. FWIW I'm running dexron 6 fluid.

 

[Night Train]

Not sure about my Buick, but my Duramax tow vehicle will run around 150 on the highway but can climb to about 200 pulling a 10000 pound trailer up a hill or on a hot day in stop and go traffic.

 

[turbows6]

That's the thing, I was essentially just running down the highway. I'm sure it will get warmer in stop and go traffic. It also has a trans brake, so that should help warm things up

 

[TR Custom Parts]

Had mine out yesterday higher 50's. 15 miles highway at about 75 and around my test loop, about another 20 miles and saw a max of 170. This was with just an external cooler with fan. Don't think fan even came on. Using Dex 6 in mine. Lot depends on where you put the probe for the temp gauge too, mine is in the pan.

 

[turbows6]

The sending unit is mounted in the fluid pan.

 

[LOT]

L/U or non L/U

That is going to make a difference. Locked/U and cruising will be the coolest.
Non L/U and stop and go will be hottest. I have the same cooling setup as the original poster and that is what I see Locked up and cruising. Stop and go which will be unlocked --I will see 180-and sometimes close to 200--get back on the open road--convertor locks and it will quickly cool back down to 140.