Do I need an aux transmission cooler?

[JustinJ94FSB]

I have a 1994 K1500 Blazer with the 5.7 TBI, 3.73 gears. I just purchased a 2024 Coleman Rubicon 1400bh camper which is rated at 1,908 pounds dry. The blazer is rated for 7,000 pounds max towing and maximum payload of around 1,500 pounds. I am trying to determine if I really need to install a auxiliary transmission cooler or if the in-radiator cooler is enough for something like this. This is a really small camper. I towed it once just to test out my brake controller I installed since it has electric brakes. It seemed to drive fine, my truck did not like the 55mph hill climbs out here in the PNW but I suppose I could just take it out of O/D and put it into D and climb the hill in the slow lane and let people go by and be fine. I don't think I will be towing it frequently, or through multiple states or anything but we do have lots of hills and mountain passes out here in Oregon. I am not experienced in towing and understanding gvwr and these types of things. This is my first camper ever, the only thing i've ever towed in my life was a 5x6 utility trailer with half yard of gravel maybe 2 or 3 times in town a couple of miles each trip. Other then that I'm a noob.

if more TV info is needed or trailer specs let me know.

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[Cadillacmak]

I have a 1994 K1500 Blazer with the 5.7 TBI, 3.73 gears. I just purchased a 2024 Coleman Rubicon 1400bh camper which is rated at 1,908 pounds dry. The blazer is rated for 7,000 pounds max towing and maximum payload of around 1,500 pounds. I am trying to determine if I really need to install a auxiliary transmission cooler or if the in-radiator cooler is enough for something like this. This is a really small camper. I towed it once just to test out my brake controller I installed since it has electric brakes. It seemed to drive fine, my truck did not like the 55mph hill climbs out here in the PNW but I suppose I could just take it out of O/D and put it into D and climb the hill in the slow lane and let people go by and be fine. I don't think I will be towing it frequently, or through multiple states or anything but we do have lots of hills and mountain passes out here in Oregon. I am not experienced in towing and understanding gvwr and these types of things. This is my first camper ever, the only thing i've ever towed in my life was a 5x6 utility trailer with half yard of gravel maybe 2 or 3 times in town a couple of miles each trip. Other then that I'm a noob.

if more TV info is needed or trailer specs let me know.

Don't tow in overdrive, and if I were you I would put a cooler on it. Nick is the expert, if he says otherwise listen to him.

 

[Carlaisle]

Given that your trailer weight is only slightly over your payload, I wouldn't be too concerned. A transmission temp gauge is an easy install that would provide useful data for many future decisions. Once installed, take a test drive over the most punishing route you anticipate and the gauge will tell you what you need to do.

 

[Caman96]

I would install one even if I didn’t tow.
A cooler and a temperature gauge. Cheap insurance!

 

[JustinJ94FSB]

I was thinking of doing the same thing I've seen in here that people have done. One installed the factory cooler and lines and everything, and one just upgraded his factory one to a B&M one like a m7b or something. I like both of these options however I'm pretty sure I just bought the last gm genuine aux trans cooler line (from radiator outlet to aux cooler inlet) in existence. And the gm genuine line that goes from cooler back to transmission doesn't exist anymore. So I'm left with a decision of what aftermarket brand to choose. AutoZone has Doesntlast brand, or I can get dorman which I've read many reviews that they leak after a couple years, rock auto sells "sunsong" straight from China. Other people recommend inlinetube or something. I've read that their factory matched bends are not even close so installing them isn't fun. Anyone have a brand recommendation for a cooler line from cooler to trans? Don't want to find out that they failed when I'm stranded in the middle of some mountain pass with a transmission that leaked and ran dry and fried lol.

Thanks

 

[Sean Buick 76]

Yes anyone with a truck without an aux trans cooler should make the upgrade.

 

[Carlaisle]

I have used inline tube for brake lines and was very pleased with their product and customer service.

 

[95burban]

Yes, a hot trans is a dead trans. And I would also consider getting a hitch that doesn’t have as much drop or a quality load stabilizer. You have a real short truck and once you start loading the trailer it will get heavy quick.

 

[JustinJ94FSB]

Yes, a hot trans is a dead trans. And I would also consider getting a hitch that doesn’t have as much drop or a quality load stabilizer. You have a real short truck and once you start loading the trailer it will get heavy quick.

Thank you, I will look into this.

 

[JustinJ94FSB]

I was looking at installing the factory aux trans cooler on my blazer and the OEM GM cooler doesn't exist new anymore. I see I might be able to get the 96-00 cooler (GM 89022535). They look identical but something must be changed or it would show as a direct fit for mine. Anyone know what changed? I have a feeling it just would need the 96-00 fittings removed and the fittings for the 94-95 (GM 15990593)installed. I need to visit my local wrecking yard again, I didn't think to look into that when I was there last and had both coolers in my hand. I noticed they had different fittings. Just don't want to try and figure it out by buying one. I might go with the larger b&m or tru-cool ones other members have done on here, I just like the idea of all factory installation on this truck. It's kind of a restoration project is why. The blazer isn't a daily driver or going to be my tow vehicle for very long or for even very many trips. But with the prices of used cars right now it is what it is. I'd like to be able to take a couple camping trips without smoking my trans.