Transmission Temps

[jhbrennan]

2008 Avalanche 5.3l 3.73 gears - I consistently see temps in the 190's while highway cruising (70 mph or less) and NOT towing. I even saw 201 coming home today after a 16 mile commute, ambient temp about 88, air conditioning on. From what I've been reading these temps seem on the high end of the range. Should I be concerned if I tow a relatively light load - 5,000 lbs or so?

[todoubled05]

2008 Avalanche 5.3l 3.73 gears - I consistently see temps in the 190's while highway cruising (70 mph or less) and NOT towing. I even saw 201 coming home today after a 16 mile commute, ambient temp about 88, air conditioning on. From what I've been reading these temps seem on the high end of the range. Should I be concerned if I tow a relatively light load - 5,000 lbs or so?

 

 

 

I get 198 200 daily.. no problems.. try searching for "tranny temps" might beable to find some more info..

[yv1650c]

mine normal conditions it's 77 C about 170 F

[BigRedTruck]

2008 Avalanche 5.3l 3.73 gears - I consistently see temps in the 190's while highway cruising (70 mph or less) and NOT towing. I even saw 201 coming home today after a 16 mile commute, ambient temp about 88, air conditioning on. From what I've been reading these temps seem on the high end of the range. Should I be concerned if I tow a relatively light load - 5,000 lbs or so?

 

 

Did your truck come with a towing package , which should have a transmission cooler.

If not, the only cooling for your transmission is the cooler internal to your radiator, which runs in the upper

one hundreds to the lower two hundreds. What does your water temp gauge reading during these conditions?

 

With high outdoor ambient temps and the air conditioning running which is pushing more heat through the radiator

200's are not out of the question.

 

As for towing, you may see 220's to 230's depending on the weight of the load, terrain, outdoor temps, and if the air is on.

Just for an experiment, when you see these high temps, run the windows down, turn the heater on hot, and run the fan at full speed.

It will get a little warm in the truck, OK hot maybe, but this will act like another radiator to the motors cooling system.

 

You may not see the Analog temperature dash gauge move, but lets see if the tranny temps come down at all.

 

If you do have a external tranny cooler, it sounds a little warm with no load.

[C & A s Dad]

Jeff my bet is you do not have an external cooler. IMO I do not want to see anything over 200. As alread said, if you hook 5,000 lbs to this truck on a 95 degree day, you are going to see temps above 225.

 

See if you have a cooler. If you do it will be mounted in the middle of the grille, will be apprx 5" x 11" and looks like a small radiator.

[jhbrennan]

Jeff my bet is you do not have an external cooler. IMO I do not want to see anything over 200. As alread said, if you hook 5,000 lbs to this truck on a 95 degree day, you are going to see temps above 225.

 

See if you have a cooler. If you do it will be mounted in the middle of the grille, will be apprx 5" x 11" and looks like a small radiator.

My Avalanche does have a "towing package" but transmission cooler is not part of the package unless you get the 4.10 rear end or the 6.0l engine. I'm going to have the dealer add one. Thanks for your responses.

[C & A s Dad]

Jeff,

 

Nothing at all against the Dealer but if you are mechanically inclined at all, this is a pretty easy job. You can find several recent post on the forum with pics showing where others have done this. Also, if you live in a hot climate as I do, you can use a larger stacked plate cooler than the OE unit. The OE piece is a great cooler but is designed for trucks that operate in climates from TX to MN. In other words, hot climates can certainly benefit from a larger cooler without overcooling the trans in the winter.

 

Good luck and you are doing the right thing. You will see those temps come down.

[Starrman]

I just towed my 18' tandem axle car trailer for the first time since installing a ScanguageII where I could monitor transmission temps. I was only hauling a Craftsman 42" cut lawn tractor, so it wasn't quite as heavy as a car, but the trailer weighs about 1200-1300lbs.

 

The outside temp was about 95* and when not towing the tranny temp hits 175* max, and normally around 165-170*. While towing in D and Tow/Haul mode on, the temps reached a max of 188* around town and 185* on the highway. I'm thinking the tranny temps will get a bit higher when I have a heavier load on the trailer as usual, like about 3500lbs. The engine coolant temp always runs right at 195

 

I'm really considering swapping out the stock cooler with the Hayden Rapid Cool 11x9.5" stacked plate style cooler, I just don't want it to be too cold in the winter. Last winter, I always waited a couple minutes after startup for the tranny temp to hit at least 50* before putting it in gear.

[slimjim2525]

200 degree temps, and not towing is way too high IMO. I run around 160 to 170 degrees with mine, and the temp was 89 degrees today.

[nfisherman]

I added the GM cooler to my Yukon XL w/5.3 L and I just took a 650-mile trip from St. Louis to northern Michigan. The car was loaded up with the family (5 of us), the dog and luggage. I towed my boat, loaded with vacation stuff (4,000 lbs. total). I drove 75 mph on interstates and 60 on state highways. The outside temp was between 80 and 90 degrees. My transmission temperature never got above 190. It was usually between 175 and 185, but it came up a bit in a traffic jam near Chicago.