How hot is too hot?

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mva

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A friend of mine asked me if 106C is an acceptable tranny fluid temperature. He reached 106C towing a 7500 lb trailer up a long hill, in 30C weather, with his 2010 Chevy Silverado.

The dealer told him that the truck will go into limp mode at 142C.

Is 106C fine in a automatic tranny?
 
106C=222F

Just type into Google 106c=?f or whatever temp you are seeking. Also works with inches/centimeters, kilometers/miles, etc.
 
223f is really hot, he needs a cooler or a bigger one if it has one already and maybe a deeper pan. 24 oz of lubeguard red (2 bottles) will help reduce the temp somewhat and is highly recommended. 200f max when towing should be okay.
A high quality oil like Amsoil ATF will help, the unit is really taking a beating at that temp.
 
That's far too hot. That transmission will be dead shortly if he keeps that up. Add the biggest transmission cooler available, and those temperatures should go down.

160-180*F is ideal for an automatic transmission. (55-70*C)
 
Math isn't your strengths...But many continue to criticize others' English and grammar in other threads..
Math Nazi on reporting in
 
Originally Posted By: HTSS_TR
160-180*F is 70-82*C


Thanks for the quick replies. Just to clarify the units:


106C = 223 F = temperature tranny was running at

142C = 288 F = dealer says fine up to this temp.

70C to 82C = 160F to 180F = normal range for auto-tranny (per sciphi)
 
220F/104C neighborhood is fine for short duration, but I would begin reducing loading/speed to try to keep it from going up much more. I would go a little more conservative than the dealer and try to keep it under 250F/121C or thereabouts.
Long term, I'd prefer it to be under 200F/93C.
The longer it is at the higher temperatures, the more often the fluid has to be changed.
Also, I have this conversion memorized due to me growing up in America, when I hear a Celcius temperature, all I can think is, "Thats nice, but I have no idea what that means."
F = C * 1.8 + 32
C = F - 32 / 1.8
 
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Too hot, but from what I have learned, it depends on how long it stays at that range. Short blips that cool down to normal range are not too bad, but if it stays there, that is not good. For short blips, I'd say an aux cooler is a good idea, and if it stays there, then he NEEDS an aux cooler.

He should do homework into which ones are good candidates for his application.
 
106C is about 223F.
At 220F, fluid starts to fatigue.
At 240F, varnishes can form.

Your friend's short term high heat is not the best, but remember it was temporary under grueling circumstances.
He cut some life from the fluid, but it should not be trashed.
 
Originally Posted By: DrDusty86
Math isn't your strengths...But many continue to criticize others' English and grammar in other threads..
Math Nazi on reporting in


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made pizzas with my 6YO son on Saturday.

He cut 15 slices of pepperoni stick, then asked how much Cabanossi to cut...I said 3 times as much as th pepperoni.

"But Dad, I don't know 15 times tables"
"Well do 15 threes instead"

"Nah, I'll do three tens, and three fives and add them"
 
I would invest in a car radiator sized transmission cooler, and a deep sump pan for that truck.

You can get all the parts from bulkpart.com, for probably under 150 dollars.
 
Quote:
How hot for how long? I's just like cooking!

That's the big question isn't it. I wouldn't have any idea about how long is too long. IMO best not to let it get there in the first place.

Nice analogy!
 
Way over temp in a trans, nuttin' to an engine's sump full of good oil.

And I call [censored] on the Chevy trucks overheating because of electric fans. We run Silverados in 100 dgree heat every summer with towing, idling, etc. TOUGH duty cycle.

The gauge never moves.

Note that the PCM starts making adjustments at around 240 or so trans temp. It pulls timing, unlocks the TC, etc.
 
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