Towing temps hit 220 this past weekend

[TowGMC]

Pulling about 6800 lbs- race car, quad, 2 sets of wheels and tires in enclosed trailer- got stuck in stop and go traffic on the interstate so the Denali was shifting between 2nd and 3rd a lot. Outside temp was close to 90, a/c on. With all the trans gear changes the trans temp touched 220, stayed between 210 and 220 for quite a while until traffic let up and I was able to get back up to a steady 70 and no shifting. I've never seen sustained temps this high before, but don't ever plan to see it again

New big Derali cooler ordered today. Plan to have it in for this weekend's tow.

 

[AJ847]

Ed, hello from another Illinois member... Quick question for my reference, what's a better trans temp at load like that, or what would have been preferable? I've been towing a couple jet ski's on trailer as well as a 20 foot seadoo boat without noticable issues (at different times) but haven't paid attention to the trans temp. I've been launching in fox lake and Lake Michigan at Evanston beach.

 

[TheFuzz]

AJ, trans temps vary greatly depending on load but generally temps in the 210-220 sustained range are ok for most vehicles while towing. Not ideal of course, but ok if it's just on a temporary basis while towing. I'd say that 190-200 is better for towing, but a lot depends on your vehicle, the maintenance you do, the load you're towing and how long you're towing it for.

I wouldn't get too concerned unless temps jump into the 230-240 range - that's when you're pushing the temp limits of most transmission fluids and run some serious risk of cooking the hard parts in your trans. If you tow a bunch and see those higher temps on a regular basis, putting in an aux trans cooler is a really smart move.

 

[livingez_123]

Sure would be nice to have an electric fan on that new trans cooler. Sitting in traffic will still get it hot if there isn't any air moving over it. They are thermostatic controlled, and some even have a manual bypass switch. just something to think about.

 

[TowGMC]

Ed, hello from another Illinois member... Quick question for my reference, what's a better trans temp at load like that, or what would have been preferable? I've been towing a couple jet ski's on trailer as well as a 20 foot seadoo boat without noticable issues (at different times) but haven't paid attention to the trans temp. I've been launching in fox lake and Lake Michigan at Evanston beach.

I'm sure you're fine. Good friend that I race with has a 2009 Tahoe that he uses to haul his race car on an open deck aluminum trailer, all in weight of about 4500 lbs. In the traffic we hit last week when I was at 220 he was running 195, and he's usually in the 190-195 range when towing.

From what I've always been taught after 30 years of towing is that you want the temps above 180 or so in order to burn off impurities in the oil, but 220 is the absolute max for any sustained towing. Ideally in the 185-195 range. The folks at Redline oil prefer ATF to be in that range for any extended period, and they say that 220 is OK but not ideal, and anything above 220 is bad with factory fill oils. And of course the trans fluid and filter should be changed far more often than the 100,000 miles the factory says. In your case I would do it every 2 years, on mine I do it every fall after race season is over, but I'm pushing the limits of what a Denali can do anyway.

So where in Chicagoland are you? Wheaton here

 

[SmallXL]

you are fine at that temperature. It may reduce life of fluids, but likely the miles that you are actually at the higher temps is few and far between. Here's a general guide to temps and conditions: