Chevy Trans temp towing (5.3L)

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Curious what others out there that have the Chevy/GM 5.3L V8 vehicles see for max trans/eng temps when towing. I have a 2012 Tahoe with tow package, and this past weekend returning home was hitting 210-215 a few times and rarely got below 190, it was around noon and fairly warm day (for CO).  What really peaked my curiosity is we were passed by a similar model Tahoe pulling a camper I'd guess weighed 2-3000lbs more than the rpod. So if I'm hitting 210... I can't imagine what their temps must be (I'm not flooring it, but I'm not usually the slowest vehicle either)
The most I've ever seen is about 225-230 if I really push it in warm weather, but I generally try to keep things under ~200 and max at 210-215 (for as short a time as possible).  The high temps are hit going up the longer passes, so ~5-10 miles constant uphill, usually 40-50mph.
I've been trying to find anything even remotely official online and so far I've seen everything from:
"over 200 and your transmission will explode"
"anything less than 250-270 is fine, that's when the warning light comes on" 
"i hit 200 in vegas summers going to get groceries w/o even towing"

What is really puzzling is there doesn't seem to be any official GM/Chevy information that I've found. 

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COSPod Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 20 Jan 2014 Online Status: Offline Posts: 38	Topic: Chevy Trans temp towing (5.3L) Posted: 18 Jul 2016 at 11:57am
	Curious what others out there that have the Chevy/GM 5.3L V8 vehicles see for max trans/eng temps when towing. I have a 2012 Tahoe with tow package, and this past weekend returning home was hitting 210-215 a few times and rarely got below 190, it was around noon and fairly warm day (for CO). What really peaked my curiosity is we were passed by a similar model Tahoe pulling a camper I'd guess weighed 2-3000lbs more than the rpod. So if I'm hitting 210... I can't imagine what their temps must be (I'm not flooring it, but I'm not usually the slowest vehicle either) The most I've ever seen is about 225-230 if I really push it in warm weather, but I generally try to keep things under ~200 and max at 210-215 (for as short a time as possible). The high temps are hit going up the longer passes, so ~5-10 miles constant uphill, usually 40-50mph. I've been trying to find anything even remotely official online and so far I've seen everything from: "over 200 and your transmission will explode" "anything less than 250-270 is fine, that's when the warning light comes on" "i hit 200 in vegas summers going to get groceries w/o even towing" What is really puzzling is there doesn't seem to be any official GM/Chevy information that I've found.

CharlieM Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Nov 2012 Location: N. Colorado Online Status: Offline Posts: 1797	Posted: 18 Jul 2016 at 12:40pm
	So you've discovered one of towing life's deep mysteries. You will not find a factory answer to tranny temp. I've tried with Toyota and been similarly unsuccessful. I couldn't even get them to tell me what temp activated the idiot light. I think part of the problem is that the oil degradation is a time-temperature product function. That is, high temps for short times maybe OK, but longer times at lower temps may add up. Then there is the issue of where the temp is measured. My Tacoma has two sensors, one in the pan and one just after the torque converter. The converter output is consistently hotter, but for shorter times. The sump is much slower to respond. I see 230-250F at the converter on long mountain climbs, but it quickly drops. You would not see these extremes if you're measuring sump temps. Bottom line, I can't give you a number and apparently no one else can or will either.
	Charlie Northern Colorado OLD: 2013 RP-172, 2010 Honda Pilot 3.5L 4WD PRESENT: 2014 Camplite 21RBS, 2013 Supercharged Tacoma 4L V6 4WD

Guests Members Profile Send Private Message Find Members Posts Add to Buddy List Guest Group	Posted: 18 Jul 2016 at 3:59pm
	Ambient air temp will have an effect on this, to a degree. Mine stays about 190-210 while towing, in the summer. I am not sure at what point in the "system" this is measured (as mentioned by Charlie). To me, this makes sense, as it is flowing thru the same radiator as the engine coolant - which according to the dash gauge, is 210. (This never varies) If you are not using "tow/haul mode", you may want to try it. This prevents converter lockup, and increases engine RPMs. This will increase the flow of the transmission fluid (and a couple of other things). Monitor the color of the transmission fluid. If it changes from red to a brownish color, you are running too hot (and/or your fluid is very old). Change the fluid. Like engine oil, this is a "service item" that needs done at intervals. Check your owners manual for severe duty recommendations. If it still seems a problem, you can always install an aftermarket/aux cooler, in front of the radiator. Install it in the line leaving the radiator/returning to the transmission.

Guests Members Profile Send Private Message Find Members Posts Add to Buddy List Guest Group	Posted: 18 Jul 2016 at 4:30pm
	PS - You may want to check/clean your radiator. It may have a build up of dead bugs, etc. reducing it's efficiency.

COSPod Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 20 Jan 2014 Online Status: Offline Posts: 38	Posted: 19 Jul 2016 at 10:17am
	thanks for info, that makes me feel my temps aren't anything out of the norm. Surprising the manufacturers doing give clearer info, but perhaps it is the wide variety of temps/terrain/towing that make it near impossible to give a normal range. Still would think they'd give a max. I'll give the grill/coolers a good hose down, that may help a bit as we've had some wetter years and the bugs definitely seem worse than in past.

Guests Members Profile Send Private Message Find Members Posts Add to Buddy List Guest Group	Posted: 19 Jul 2016 at 10:55am
	You are welcome. I'm not a certified mechanic but, what you describe sounds normal to me. Occasional temp rises are going to happen under load. This is one of the things that makes the fluid "wear out" - especially/more quickly when towing on a regular basis. I change my trans fluid about every 25-30K miles and check the color on the dipstick 2-3 times per season. I just hosed mine, as I had a lot of bugs on the bumper/windshield (I was washing the truck anyway). Anything the manufacturer says.....they will need to be able to back it up with their checkbook and/or lawyers. I suspect that is why they are rather "non-comment" about the matter. You might pass along which transmission you have - the 4 speed or (probably) 6 speed. They behave a little differently from each other. I did not like Tow/Haul with the 2009 4 speed (5.3 Silverado) but, I do like it with the (6 speed, 5.3) Silverado I have now.

COSPod Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 20 Jan 2014 Online Status: Offline Posts: 38	Posted: 19 Jul 2016 at 11:30am
	Yes it's the 6 speed. Tow/Haul mode works well from what I can tell, I don't sense it ever "hunting" for gears causing constant up/down shifts which is nice. It is a little discomforting when it revs above 4000-4500rpm, but that seems to be what it takes on some of the longer/steeper stuff.