Popup - Cooler Needed?


Original poster
Jan 29, 2012
I'll be towing a pop up from Michigan to Montreal, Acadia, Boston and back to Michigan. I'll also have our bikes on a dual hitch with hitch mount bike rack.

My question is whether I need an auxiliary transmission cooler or not. I towed it a few hours last weekend empty, and it didn't look like the temp gauge moved at all. Thoughts and opinions?

Here's the pop up in question. I've previously towed it with an Aztek, to Yellowstone and back. I did have a cooler on the Tek.



Nov 18, 2011
Not sure if needed, but it is cheap insurance.... I would spend the 60 bucks and slap one in there.

Also the gauge on the dash is not real. More of a....well..... ask Roadie about the gauge's accuracy.


Lifetime VIP Donor
Nov 19, 2011
Portland, OR
I'd put on a cooler. Very cheap insurance. And get a Scangauge II to tell you the transmission temperature and the TRUTH about engine coolant. To avoid alarming the average numb-nuts (non-enthusiast) owner, the dash gauge sits at straight-up 210 degrees for any TRUE coolant temp between about 185 and 225. Don't trust it except as a display of total coolant loss and redline operation.
Feb 24, 2012
You probably don't need a cooler for something that small. But it's good insurance, I prefer an external trans cooler for any vehicle.

If you do go for an external cooler, get a good one, and make sure the install is done right. Nothing worse than a leaking trans fitting you will be cursing all the way to AAMCO, if you didn't need the fire department onsite...


Nov 20, 2011
If you had the I6, I would say yes, just because of their loose torque converter that makes heat like CRAZY. My trans temp stays below 200F towing a 6500# car trailer on a 90F day, with the A/C on, NOT in mountain switchbacks. If you were going to be in the Rockies or out west, or far south, I'd say it's cheap insurance, but this trip, with this trailer. No problem.



Jan 26, 2012
Insurance is a relative term, so is cheap. If you have ability, time and tools to tap into trans lines and fabricate brackets then you can indeed do it "cheap". If you're good enough that these fittings won't leak or break during your maiden voyage then yes it can indeed be insurance as well. My worst fear is screwing this up and ruining a trip and possibly a transmission. This fear can be mitigated by hiring it out or buying an idiot proof kit but then the "cheap" aspect goes out the window and I return to wondering if it is actually necessary or not.

I have been surfing topics on this matter recently and I cannot come to a conclusion without my own empirical evidence. I did find some good data by a fellow 5.3 owner a month or so back but he was carrying a larger load through much tougher terrain. Next weekend I'll be towing something between your pop up and bartonmd's 6500# load and if I can ever get the Torque app to properly read the trans data I'll find out for myself if my situation requires or could benefit from additional cooling.


Original poster
Jan 29, 2012
I think you just nailed my thoughts! After a little more looking and scheming, I'm fairly confident I can do the install myself. BUT, there is that little bit of self doubt. I don't want to be a long ways from home and have a problem. That being said, it is a pretty simple job, I think it unlikely I could goof it up in such a way as wouldn't be obvious right away.

Cheap is relative: truer words were never spoken!


Dec 6, 2011
There is an adapter that will go into the radiator's tranny cooler connection to give you a hose bard connection point. IIRC runs less than $10. So hooking up the cooler is a matter of just getting its hoses on the original line from the tranny and the new hose bard and cinching them down with hose clamps. A lot easier than cutting lines. You should be able to get it at anyplace you get the cooler from. Try eTrailer.com.

Keep the cooler away from the outside air temperature sensor that's just behind the grill. Not critical but if you don't it will through off the temp readings.


Mar 7, 2012
bump to the trany cooler, its good insurance. I tapped mine in after the stock cooler so the fluid runs through the stock cooler and then the aux cooler. If your picky like i was and want the best cooler for your money get a "stacked plate cooler" instead of a "tube and fin" transmission cooler, they do a much better job of dissapating the heat. I got mine from summit racing.


Jan 26, 2012
Pulled this about 120 miles one way in 85-90 degree ambient temps last week. Weight approximately 3500# and somewhere in the neighborhood of 900# in passengers and gear. Mildly hilly terrain with a short 20 mile highway section and a few minutes spent idling waiting for a construction crew who had the road shut down to a single lane. Trans temp high was 208.4 deg F according to the Torque app. Next time I'll remove the windshield from the SxS to cut down on drag, but I'm in no hurry to install an aux trans cooler. If I find myself flush with cash and with some extra time thought I certainly wouldn't be opposed to the idea.



Dec 8, 2011
GM's official stance is that an axillary cooler is not needed. I don't have one and tow a 3500# box, and have done so on a trip to Yellowstone via I-90 when it had about 62 on it. My TB now has 145k on it. Change trans fluid religiously every 50k. So do you need an axillary cooler to tow a PUP? If you'll sleep better at night, by all means. They aren't expensive and are an easy DIY job.


Dec 4, 2011
Ottawa, ON
This thread is about a TB pulling a 3150# travel trailer (unknown if I6 or V8), it is having issues with increasing temperatures during long hill climbs with an auxiliary cooler.


I put a cooler on ALL my vehicles, whether they tow or not and those that do tow, even just rarely, put the biggest available. Not to beat a dead horse, but it is cheap insurance. And as it was once advertised "you can pay me a little now or a whole lot more later". For those few times where the temperature could climb, it will protect your tranny.
Dec 4, 2011
Its been said already many times :thumbsup: to the cooler. I like the Tru-Cool and I have a 4589 that fits real nice on the drivers side of the center latch for the hood. The standard sequence is tranny to radiator on the passenger side. Out of the Radiator on the drivers side to Aux Cooler input, out of Aux cooler to tranny. There are many ways to attach the hoses to the cut off ends of the tranny tubing. I like the compression fitting on the tubing and a corresponding screw type fitting on the hoses from and to the cooler. However many, many people have just put a hose clamp (or two) on the rubber hose pushed onto the tubing.

Here is a post of my install on the old site (post 42) I couldn't find my original

My tranny cooler hook up with pics - Page 3 - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

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