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Towing temps?

Yeah......I keep telling my wife that it's 75 MPH on 77, 85, and 485.......
 
I didn't even think about the speedo. I was just cruising back from the lake and was going with the flow of traffic when I thought about Derrick's post.
 
spinzone said:
D, I snapped this pic for you running on the interstate. Normal temp, not towing anything. 218* wouldn't scare me.

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Thanks! Although if you aren't towing anything, does that make 218 seem more reasonable, even though I was doing 20mph less than you!! Haha, but in hilly terrain. 
 
Run a few full tanks of 91 in it, you will be AMAZED how much better the truck runs overall.  Wont even take a full tank to see a difference.  
 
The GM's do use synthetic trans fluid.  I found that fact when I got the bill for a fluid service on the 2009 Suburban transmission at 70,000 miles.  I am glad the speedometer on my truck also has the km markings.  600 miles of towing in Canada last week, it lets me know how much over the speed limit I am going.  The first 6 road signs after the border are all the rules about what you are not allowed to have or do on the road. Derrick, why are the speed limits so darn slow?

Back on subject, my tranny never gets above 185.  In tow mode, it seldom lets it into 6th gear but I really like the engine braking.  The 9.2 miles per gallon hurts but is better than the old Suburban that got 6.9 mpg towing. 
 
Derrick, take it to the car wash and clean the outside of the radiator and coolers, if you can, try to spray from the fan side out.

Don't get too close with the wand or you may 'lay over' some of the cooling fins. You might be suprised at the amount of dead bugs and road debris that gets in there.
 
We just pulled our 21slx for 160 miles on the interstate with our Tahoe. Temps in the 180s.

Brian
 
Did you watch it while going up any steep hills or when motor was working hard? Mine will cool back down, but the first while into the Park is all inclines. Thanks for letting me know though, appreciate it.
 
spinzone said:
D, I snapped this pic for you running on the interstate. Normal temp, not towing anything. 218* wouldn't scare me.

Click to expand...
Thanks for the pic, Now I know I have this on my truck after 6 months. I guess I need to read the book.
 
Wow, I looked at Spins post a couple times and until KC quoted it, I thought it said 218* would scare me, not wouldN'T like it actually says! Haha
 
GMs response to the 6l80 transmission temp question.

We understand the importance of this information to keep the vehicle in the best condition and we are more than happy to provide the information for you. The normal operating temperature is at 180°F to 200°F or 82°C to 93°C. The message 'TRANSMISSION HOT IDLE ENGINE' will appear on the Driver's Information Center (DIC) if you drive the vehicle when the transmission fluid is overheating. You will also hear a chime if the transmission fluid gets hot. Driving with the transmission fluid temperature high can cause damage to the vehicle. Stop the vehicle and let it idle to allow the transmission to cool. This message clears and the chime stops when the fluid temperature reaches a safe level.

I hope this information has been of help. If you should need further assistance, simply reply to this email or call our Chevrolet Customer Assistance Center at 1- 800-222-1020. Customer Relationship Specialists are available Monday through Saturday from 8:00 a.m. to 9:00 p.m., Eastern Time. I am usually in the office Monday through Friday between the hours of 8:00 a.m. and 5:00 p.m., Eastern Time.

From GMC4x4 site

"In the February 2011 issue of Trailer Life magazine RV Clinic in response to a reader about the maximum transmission temperature allowed in a 2009 Chevy Silverado, the Tech Team had this response.

"General Motors’ in-house towing team expert provided RV Clinic with this statement: The maximum allowable automatic transmission fluid temperature is dictated by the transmission oil itself. The oil begins to degrade significantly above 270 degrees Fahrenheit, so we design vehicles so that in all but the most extreme conditions, the fluid temperature in the transmission sump stays below 270 degrees F.

We allow for up to 285 degrees F in extreme conditions (i.e. towing a trailer with combination loaded at GCWR in Death Valley). But for customer usage anywhere else in the country, even at GCWR, transmission sump temperature should stay well below 270 degrees F. Above this point, certain internal components, such as seals, begin to disintegrate rather quickly. Although newer synthetic fluids can withstand higher temperatures we still recommend this (270F) as a maximum temperature. ""
 
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Sheesh you're a handy guy to have around Chas! Now it makes sense why the wife keeps you! hehe jk Thanks for the info, makes me feel a little better. I still don't love seeing it get up that high, but at least its usually only for a very short time.
 
spinzone said:
GMs response to the 6l80 transmission temp question.

We understand the importance of this information to keep the vehicle in the best condition and we are more than happy to provide the information for you. The normal operating temperature is at 180°F to 200°F or 82°C to 93°C. The message 'TRANSMISSION HOT IDLE ENGINE' will appear on the Driver's Information Center (DIC) if you drive the vehicle when the transmission fluid is overheating. You will also hear a chime if the transmission fluid gets hot. Driving with the transmission fluid temperature high can cause damage to the vehicle. Stop the vehicle and let it idle to allow the transmission to cool. This message clears and the chime stops when the fluid temperature reaches a safe level.

I hope this information has been of help. If you should need further assistance, simply reply to this email or call our Chevrolet Customer Assistance Center at 1- 800-222-1020. Customer Relationship Specialists are available Monday through Saturday from 8:00 a.m. to 9:00 p.m., Eastern Time. I am usually in the office Monday through Friday between the hours of 8:00 a.m. and 5:00 p.m., Eastern Time.

From GMC4x4 site

"In the February 2011 issue of Trailer Life magazine RV Clinic in response to a reader about the maximum transmission temperature allowed in a 2009 Chevy Silverado, the Tech Team had this response.

"General Motors’ in-house towing team expert provided RV Clinic with this statement: The maximum allowable automatic transmission fluid temperature is dictated by the transmission oil itself. The oil begins to degrade significantly above 270 degrees Fahrenheit, so we design vehicles so that in all but the most extreme conditions, the fluid temperature in the transmission sump stays below 270 degrees F.

We allow for up to 285 degrees F in extreme conditions (i.e. towing a trailer with combination loaded at GCWR in Death Valley). But for customer usage anywhere else in the country, even at GCWR, transmission sump temperature should stay well below 270 degrees F. Above this point, certain internal components, such as seals, begin to disintegrate rather quickly. Although newer synthetic fluids can withstand higher temperatures we still recommend this (270F) as a maximum temperature. ""
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Hmmm, my 20+ years in the business have made me efficient, I typed out basically the same info in just a couple sentences as GM wrote in a paragraph lol.
 
Wild and Free said:
Most all tranny oil is synthetic or a blend and is more than capable of running 230-250*f safely but if higher than that for an extended period would warrant a fluid change. Don't buy into the gauges on the dash they are about the most inaccurate things on the planet, nothing more than indicators, I have add on OBDII gauge tuners on most of my vehicles and while in normal operating temps on the dash gauge can be a 40* difference on the actual readings.

If you did not see any warning lites don't worry about it, they are set to alarm before danger zone temps set in to let you slow down or cool down before damage occurs.
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Here was my initial post not sure why it didn't show in the same multi quote window though.
 
Sorry W&F, wasn't discounting your info, but obviously I would have no idea you had 20+ years in the biz. I do like reading a direct statement from the company saying their thoughts though. I also was chatting with one of my regular customers today, (he's retired, so now he fixes small engine stuff, which is what I always deliver to him) and I find out he used to own a Transmission Shop! For over 20 years! He responded pretty much exactly what you guys both said. He said 160 is a nice temp, but if you're towing anything that will go up, and that if it ever said 275 pull the heck over! !
 
Another thing to remember with any and all auto transmissions is fuller is never better. Always run in the mid safe hot range, they can and do easily overheat with too much fluid.

Also depending on where mfg's measure the temps at make a huge difference, if measuring inside the tranny like a sensor in the valve body or in the oil pan is about the coldest oil in the system as it has already returned from the cooler system and is dumped back into the sump and if one sees 250+ in those places it is already overheated. if measured in the converter output line which is usually the line leaving the trans headed to the cooler is the most accurate spot and real actual temps created already. 270 there is the max, 270 inside the trans is already deep fried or soon to be.

I ran 2 temp sensors in my 02 Dodge Cummins which I had built up and power pulled and drag raced it and I regularly saw about 30*f difference between the pan temps and converter output temps, pan being colder of the 2 and is the easiest place to put a sensor and so companies tell everyone to do it there which is the scary part but they get to sell more parts after the tranny fails due to folks taking that as the gospil truth.
 
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