2016 Sierra trans temps...........
 

Saw a high of 194* on the highway and now usually 190* and then coasting down on the off ramp doesn't seem to drop for a few miles/ I understand that these new trucks have a thermostat controlled trans line that opens when deemed necessary. can this be tuned lower? Oh yeah- truck is a 2016 GMC Sierra 5.3 6spd. Just looked around upfront as I didn't get to putting on the Tru Cool on last truck but I don't see an aux cooler for the trans. Any info greatly appreciated...………….. TIA

40k tru-cool will get that thing down to like 150 on a hot day

No doubt there, Terra, but there is not an existing trans cooler there to start with...………..

I can't remember who but he is 14+ that gave a play by play on what to do to lower trans temps. No cooler needed. I have a 40k as well but it wouldn't fit with the he of the Whip. He tells how to easily and simply mod the 6spd to bring it down to 140-160 as I recall. Btw my temps are the same. Just search it.

I googled around and found a thermostat delete, guess I'll hafta review the procedures for gutting the thermostat B4 diving in. Finding out that this is intentional by design I do feel a lot better, I was starting to think I had a clogged line somewhere- but one lingering question is at what temperature should I start getting concerned about things...……………..

220-230+ is what I would call the start of the danger zone.

Anything from 160-200 is perfectly fine and basically where they want the transmission temps to stay for fluid life and over all performance.

That brings a lot of peace of mind, FF. 196* is the highest I've seen- was just getting kinda leery that I was mostly over 190* and now knowing it's a design parameter in that they want the fluid that temperature for functioning, I'm gonna sleep better now...………..

If you want even more to go by the owners manual should have a blurb about checking the fluid level as well and they list the temp that they suggest the transmission be operating at.

I've seen 204-205 at least after back to back passes. Drove it back in a lower gear with the heat on lol.