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so i towed my race trailer back from thunder hill . I weighs about 5000 loaded and when I was coming out of Redding I had Ben going 70 up hill for 30 or so miles when all the sudden the tranny let go it was aggressive and it went into limp mode ! I **** ! I let it cool of and it worked fine I would start it and let it idle then shut off for a few after about 70 more miles or so the ce light went off and it worked great all the way home . So my question is at what tranny fluid temp do I pull over and let is cool ? I was not watching the gauge couse this thing pulls that trailer so dam easy . And is there aftermarket stuff I need ? Please help .lol
 

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I have a long heavy tow this weekends. 6500lb up into the Tennessee mountains.

I’ve seen temps in the low 200° range towing. I didn’t feel like it was a problem because I have seen 199° on normal traffic unloaded.

I have gotten my trans temps to drop about ten degrees while towing by turning OFF the exhaust brake/ tow haul mode after I’m up to speed. Drops into 6th gear and locks the converter after you do that.

If the truck gives me any trouble like you mentioned happening to you then I won’t even bother with it. I will sell it as soon as I get back.
 

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General rule of thumb is 225f and you should consider cooling it down. Some transmissions like the Allison (with the right fluid in it) are engineered to run that hot all day, id be surprised if this one is. Locking the converter is the number 1 way to keep the temps down, a bigger cooler is the 2nd best.

Curious, do you have ample airflow going through the grill? I love it when i talk to guys who have big bambi-bashers and fancy grills who are having cooling issues.
 

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adamuise, thanks so much for your r.o.t. I watch trans temp religiously when towing our Escape bed hitch travel trailer with a loaded Colorado. I've seen ~220F with no change in performance, but wondered what should be the max. FYI, that was backing the trailer up a tortuous, steep gravel hill in 4 low, to park it next to a country home in the NH woods. I think the high load at low speed really works the drive train - but no noticeable problem.
 

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adamuise, thanks so much for your r.o.t. I watch trans temp religiously when towing our Escape bed hitch travel trailer with a loaded Colorado. I've seen ~220F with no change in performance, but wondered what should be the max. FYI, that was backing the trailer up a tortuous, steep gravel hill in 4 low, to park it next to a country home in the NH woods. I think the high load at low speed really works the drive train - but no noticeable problem.
You are correct that high loads at low speed are tough. At low speeds the converter is unlocked and creating a large amount of heat without enough air movement to the cooler. I have seen pickups with plows have major issues because of that, plus the constant D to R shifts. Playing in the mud is another great way to kill a transmission, if its not built for it.
I'll do some digging and find out what the max for these transmissions is. Alot of variables but i'll see what i come up with
 

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I saw 225 F hauling my Toyota trail truck and camping gear while pulling Soldier Summit south of Salt Lake enroute to Moab.
Total weight 12,300 pounds.
No issues, but was definitely concerned so added tranny cooler in Moab before my return trip.
Have never seen temps over 190 F since.
Simple mod.
Remove plastic splash shield, cut hard line from tranny to red and splice in cooler using supplied hose.
I used a plate style cooler S paced forward of the cross member using some scrap square tubing.
Replace splash shield and keep cooler clear of mud if driven off road.
 

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The fluid can actually take quite a bit of abuse. 250 is no problem, 280 you're killing it. Thats just the fluid though, i do not know how the clutch packs and other internals like being hot. I'd love to take it out and see whats inside but the better half of me (wife) says no lmao.
 
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