[Rockcrawlerdude]

i know old school methods and ways of thinking don't really apply to these new fancy vehicles, but I've always been told that you want trans fluid to stay under 200° with 180°-195° being the magic number. I've always ran a cooler and a gauge on any automatic trans vehicle I've ever had (albeit, not many) this is my first time not having a dedicated trans cooler.

That being said, my Colorado was reading 200° the other day on a trip around town, no towing and about 78° ambient.

The 6L50 runs dexron vi which is very resistant to thermal breakdown and the trans doesn't have shift bands, and also is able to run with the torque converter locked up most of the time.

I don't think I should be worried but just wondering if anybody else has been seeing high ish trans temps??

 

[AndyZ71]

I'll have to pull that screen up for a bit and see what I'm reading.

 

[Rockcrawlerdude]

Stayed low on the way home from work, about 125°, but that was only 9 miles from the shop to the house not much traffic 79° ambient

 

[TERNARYTEACHER]

ive only had my trans temps reach 198 on a 300 mile trip running about 85mph. that was before I had the truck tuned. since the tune ive never seen it exceed 180 and its usually closer to 160

 

[AndyZ71]

It's been to cool here to supply any relevant data.

 

[Rockcrawlerdude]

14 miles towing 51° ambient

 

[Burgess159]

I would say that's not too bad. Would like to see it a little cooler though. My 2004 LLY Duramax would get up to 190-200 when pulling anhydrous tanks in the summer or when we took a gooseneck trailer full of atv's down to Tennessee to ride. Different transmission totally, but for being a little truck and transmission, that doesn't seem that bad.

 

[Rockcrawlerdude]

Didn't get over 202° towing 100 miles

 

[Rockcrawlerdude]

After it got this hot I took off tow haul/exhaust brake and it shifted to 6th and cooled off a little.

 

[Burgess159]

I guess I didn't realize it didn't shift into 6th gear at all in tow/ haul. I figured it would. My 2004 would run way up in 4th gear but would eventually shift into 5th (5 speed, the newer trucks are 6 speeds).

 

[Rockcrawlerdude]

Me either. I am not sure if it would have shifted into sixth if I was going faster or if it was flatter. But, after shifting into sixth gear and/or locking up the converter, my trans temp dropped back down to the 190s and I went from 12.7 MPG to 15 mpg

 

[Rockcrawlerdude]

90° ambient around town. Not towing or anything just suburban traffic lights.

 

[cranky1]

Look at the temps the newer powerstrokes run. It's high

 

[Rockcrawlerdude]

I'm guessing the dexos vi doesn't mind

 

[Burgess159]

If you're doing a lot of stop and go in traffic like that, at 90 degrees outside, that doesn't surprise me that it got that high.

 

[Snail it]

I see temps get up around the two hundred teens towing my 5600-pound travel trailer. I figure if the trans temp light does not come on I am probably okay. The engineers know what they are doing and longevity is one of their big concerns. Also, GM does not want to be paying for transmissions under warranty.

 

[smthng]

Me either. I am not sure if it would have shifted into sixth if I was going faster or if it was flatter.

I'm pretty sure it does shift into 6th in haul mode, but really winds out 5th before it does it. I think mine shifts around 63 mph in haul mode. I usually kick it out of haul mode to shift it at around 60, then pop it right back into haul mode to make it stay there. From what I've seen (and my Avalanche was the same) haul mode changes not only what speeds it'll shift at, but it also changes how much it wants to shift... in haul mode it generally doesn't shift unless it really needs to.

 

[norcaltoy]

Bumping the thread.

Curious what everyone else is seeing as average and high temps when towing as well as empty.

I've seen higher than comfortable temps a few times. Saw 235° while towing 6k up a long grade at 55mph, not unexpected but higher than I would like.

The other noticeable time, saw 240° while out exploring some back roads. Driving between 15-25mph in the mountains on a gravel road, driving mildly without any excessive throttle or hot rodding the truck.

 

[Burgess159]

Bumping the thread.

Curious what everyone else is seeing as average and high temps when towing as well as empty.

I've seen higher than comfortable temps a few times. Saw 235° while towing 6k up a long grade at 55mph, not unexpected but higher than I would like.

The other noticeable time, saw 240° while out exploring some back roads. Driving between 15-25mph in the mountains on a gravel road, driving mildly without any excessive throttle or hot rodding the truck.

Was your back road adventuring with or without a trailer? If it was, then I guess I could understand. If not, then that seems excessive.

What mileage are you at and have you changed the transmission fluid yet?

 

[apacheieip64]

I have seen my temp 200-220. I started getting a shudder in my transmission so I started monitoring the temps. Long story but dealerships, calling GMC, and a local repair shop has led me to believe there is a known transmission problem with these trucks. If it’s in warranty they have a tech bulletin to flush the transmission. If that doesn’t work they change the torque converter. My started just outside the 60k warranty. Right now my truck is sitting at a dealership in Dothan, Al and I am looking at over a 2k bill. GMC has refuse to help me with the cost f the repair. And I don’t know if this will fix the problem. I loved my truck right up to this mess.