transmission temperature getting hot
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Record Breaker
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From: live oak, ca
transmission temperature getting hot
any one moniter their trans temp? i havent worked my truck very hard yet, but now im to nervous too, i pulled a chrokee on a cardolly and i could get the temp up there but not really high, then i got in to stop and traffic, and i could pretty much peg the gauge ( 260*F) just trying very gently to get up too speed, (with the stock tires) and then the other day (big tires) just running the hills empty i could get it up there again. my sensor is in the hot cooler line just before the radiator, am i possibly picking up heat from the exhaust/cats since they are so close?
im thinking about eliminating the stock cooler and putting an aftermarket cooler up front, is it just my sensor location? should i be concerened? after about 30k miles i will service the trans and move the sensor to the pan.
im thinking about eliminating the stock cooler and putting an aftermarket cooler up front, is it just my sensor location? should i be concerened? after about 30k miles i will service the trans and move the sensor to the pan.
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From: Upstate New York
My sensor is in the tranny pan. That is where I want to monitor the temp. Not interested in the temp going to the cooler or right after it. With towing in the ADK's I have only gotten it up to 250. no more. Do you have a towing package? Did you put the tranny in tow haul mode?
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Record Breaker
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From: live oak, ca
yes, i have tthe tow package, in tow mode, it didnt seem to make a hole lot of difference, maby slowed it down a little but it still got up there,
does any one know where the hot side cooler line is coming from, like the pan, or out of the converter?
does any one know where the hot side cooler line is coming from, like the pan, or out of the converter?
I would almost bet its your sensor location. The hot side of the cooling lines come directly out of the TC through the Cooler, through a return line filter and back through the system. Thats my general understanding. I have the hydaulic schematics if you would like to look at em... Its like black magic though 
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Record Breaker
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From: live oak, ca
cooling lines come directly out of the TC through the Cooler
if the line is that hot, but the rest of the trans is at an accepable temp, everything should be ok, but what about that small ammount of fluid in the cooler,at that high temp, could it be getting burnt and contaminating the rest of the system?
and i am definatly getting a new cooler and taking the one out of the radiator, no wonder the engine temp wants to climb when pulling a hill/load.
im just real nervous about auto trans, i have never had one last me over 10k including one that i spent over $2500 just in parts, i told myself i would never buy another auto trans vehical, but i just had to have one of these
Last edited by dodgetrucker75; Jan 19, 2010 at 03:13 PM.
thats what i thinking, on another thought, at what temp does atf start to burn/discolor?
if the line is that hot, but the rest of the trans is at an accepable temp, everything should be ok, but what about that small ammount of fluid in the cooler,at that high temp, could it be getting burnt and contaminating the rest of the system?
and i am definatly getting a new cooler and taking the one out of the radiator, no wonder the engine temp wants to climb when pulling a hill/load.
im just real nervous about auto trans, i have never had one last me over 10k including one that i spent over $2500 just in parts, i told myself i would never buy another auto trans vehical, but i just had to have one of these
if the line is that hot, but the rest of the trans is at an accepable temp, everything should be ok, but what about that small ammount of fluid in the cooler,at that high temp, could it be getting burnt and contaminating the rest of the system?
and i am definatly getting a new cooler and taking the one out of the radiator, no wonder the engine temp wants to climb when pulling a hill/load.
im just real nervous about auto trans, i have never had one last me over 10k including one that i spent over $2500 just in parts, i told myself i would never buy another auto trans vehical, but i just had to have one of these
On that note I would say anything above 325 with your basic ATF, you would see the oil properties diminish in value. And as far as contaminating the system it passes through the filter before re-entering the system. So it would just be adding more debris to the filter, if per say its breaking down, of course this is all logical speculation on my part. So chime in and correct me if you think I am way off key.
Last edited by lghtngblt02; Jan 19, 2010 at 03:38 PM.
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Record Breaker
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From: live oak, ca
i found this, might make ya cringe
Why Atf Wears Out
An automatic transmission creates a lot of internal heat through friction: the friction of the fluid churning inside the torque converter, friction created when the clutch plates engage, and the normal friction created by gears and bearings carrying their loads.
It doesn't take long for the automatic transmission fluid (ATF) to heat up once the vehicle is in motion. Normal driving will raise fluid temperatures to 175 degrees F., which is the usual temperature range at which most fluids are designed to operate. If fluid temperatures can be held to 175 degrees F., ATF will last almost indefinitely -- say up to 100,000 miles. But if the fluid temperature goes much higher, the life of the fluid begins to plummet. The problem is even normal driving can push fluid temperatures well beyond safe limits. And once that happens, the trouble begins.
At elevated operating temperatures, ATF oxidizes, turns brown and takes on a smell like burnt toast. As heat destroys the fluid's lubricating qualities and friction characteristics, varnish begins to form on internal parts (such as the valve body) which interferes with the operation of the transmission. If the temperature gets above 250 degrees F., rubber seals begin to harden, which leads to leaks and pressure losses. At higher temperatures the transmission begins to slip, which only aggravates overheating even more. Eventually the clutches burn out and the transmission calls it quits. The only way to repair the damage now is with an overhaul -- a job which can easily run upwards of $1500 on a late model front-wheel drive car or minivan.
As a rule of thumb, every 20 degree increase in operating temperature above 175 degrees F. cuts the life of the fluid in half!
At 195 degrees F., for instance, fluid life is reduced to 50,000 miles. At 220 degrees, which is commonly encountered in many transmissions, the fluid is only good for about 25,000 miles. At 240 degrees F., the fluid won't go much over 10,000 miles. Add another 20 degrees, and life expectancy drops to 5,000 miles. Go to 295 or 300 degrees F., and 1,000 to 1,500 miles is about all you'll get before the transmission burns up
An automatic transmission creates a lot of internal heat through friction: the friction of the fluid churning inside the torque converter, friction created when the clutch plates engage, and the normal friction created by gears and bearings carrying their loads.
It doesn't take long for the automatic transmission fluid (ATF) to heat up once the vehicle is in motion. Normal driving will raise fluid temperatures to 175 degrees F., which is the usual temperature range at which most fluids are designed to operate. If fluid temperatures can be held to 175 degrees F., ATF will last almost indefinitely -- say up to 100,000 miles. But if the fluid temperature goes much higher, the life of the fluid begins to plummet. The problem is even normal driving can push fluid temperatures well beyond safe limits. And once that happens, the trouble begins.
At elevated operating temperatures, ATF oxidizes, turns brown and takes on a smell like burnt toast. As heat destroys the fluid's lubricating qualities and friction characteristics, varnish begins to form on internal parts (such as the valve body) which interferes with the operation of the transmission. If the temperature gets above 250 degrees F., rubber seals begin to harden, which leads to leaks and pressure losses. At higher temperatures the transmission begins to slip, which only aggravates overheating even more. Eventually the clutches burn out and the transmission calls it quits. The only way to repair the damage now is with an overhaul -- a job which can easily run upwards of $1500 on a late model front-wheel drive car or minivan.
As a rule of thumb, every 20 degree increase in operating temperature above 175 degrees F. cuts the life of the fluid in half!
At 195 degrees F., for instance, fluid life is reduced to 50,000 miles. At 220 degrees, which is commonly encountered in many transmissions, the fluid is only good for about 25,000 miles. At 240 degrees F., the fluid won't go much over 10,000 miles. Add another 20 degrees, and life expectancy drops to 5,000 miles. Go to 295 or 300 degrees F., and 1,000 to 1,500 miles is about all you'll get before the transmission burns up
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Record Breaker
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From: Upstate New York
"Go to 295 or 300 degrees F., and 1,000 to 1,500 miles is about all you'll get before the transmission burns"
now do they mean 1,000 to 1,500 miles of driving with the temp at 295 or 300?? or is it if you just touch that temp once for 20 miles your toast?
now do they mean 1,000 to 1,500 miles of driving with the temp at 295 or 300?? or is it if you just touch that temp once for 20 miles your toast?
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Joined: Jun 2008
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From: St. Louis
Probably not with as well vented as the engine bay is. But you could try wrapping the lines to see if that helps.