If you are only running 230F a few percent of total transmission hours, then I don't think you have anything to be concerned about.
Heat and Transmission Failure Charts
- Thread starter Silber Igel
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Not much, there is very little power being absorbed at idle in drive.
Originally Posted By: Mkos1980
I read all the posts about temp and so forth and now you ahve me worried. I have an 07 Grand Prix 20K miles with built in temp sensor and it runs 180* for about an hour but then after that it'll go to 205 and stay there esp on the last 12 hour trip to SC. 205* all the way there in 90+ degrees and AC on. Going up some mountains and converter unlocked it saw 230* for about 6 miles then came back to 205*.
You may want to put in an auxiliary cooler in line with the feed lines to the stock heat exchanger. Should knock those numbers down quite nicely.
I read all the posts about temp and so forth and now you ahve me worried. I have an 07 Grand Prix 20K miles with built in temp sensor and it runs 180* for about an hour but then after that it'll go to 205 and stay there esp on the last 12 hour trip to SC. 205* all the way there in 90+ degrees and AC on. Going up some mountains and converter unlocked it saw 230* for about 6 miles then came back to 205*.
You may want to put in an auxiliary cooler in line with the feed lines to the stock heat exchanger. Should knock those numbers down quite nicely.
Originally Posted By: Mkos1980
I read all the posts about temp and so forth and now you ahve me worried. I have an 07 Grand Prix 20K miles with built in temp sensor and it runs 180* for about an hour but then after that it'll go to 205 and stay there esp on the last 12 hour trip to SC. 205* all the way there in 90+ degrees and AC on. Going up some mountains and converter unlocked it saw 230* for about 6 miles then came back to 205*.
I wouldn't be too concerned as long as it is only short intervals and you plan to change on a regular basis. And you don't tow anything.
I was going to put an aux cooler on my Accord but quickly found there wasn't much room for one and the hose routing was a pain too. You might have these same issues. I also don't like the coolers that mount on the AC condensor core. In the end my local trans shop talked me out of doing it.
I read all the posts about temp and so forth and now you ahve me worried. I have an 07 Grand Prix 20K miles with built in temp sensor and it runs 180* for about an hour but then after that it'll go to 205 and stay there esp on the last 12 hour trip to SC. 205* all the way there in 90+ degrees and AC on. Going up some mountains and converter unlocked it saw 230* for about 6 miles then came back to 205*.
I wouldn't be too concerned as long as it is only short intervals and you plan to change on a regular basis. And you don't tow anything.
I was going to put an aux cooler on my Accord but quickly found there wasn't much room for one and the hose routing was a pain too. You might have these same issues. I also don't like the coolers that mount on the AC condensor core. In the end my local trans shop talked me out of doing it.
Originally Posted By: Junior
In the end my local trans shop talked me out of doing it.
I bet they did. Cha Ching!!! will come much sooner that way.
In the end my local trans shop talked me out of doing it.
I bet they did. Cha Ching!!! will come much sooner that way.
Transmission Miles to failure2,000 4,000 15,0000 25,000 50,000 80,000
Temperature 300°+ Transmission Failure
270° Damaging High Temp
Seal & Clutches Burn
250° Damaging High Temperature
Varnish Forms
230° Damaging High Temperature
Valves Stick
210° Above Average Temperature
Pressure Drops
190° NORMAL OPERATING TEMPERATURE
175° LOW TEMP=LONGER TRANSMISSION LIFE WITH
Temperature 300°+ Transmission Failure
270° Damaging High Temp
Seal & Clutches Burn
250° Damaging High Temperature
Varnish Forms
230° Damaging High Temperature
Valves Stick
210° Above Average Temperature
Pressure Drops
190° NORMAL OPERATING TEMPERATURE
175° LOW TEMP=LONGER TRANSMISSION LIFE WITH
Originally Posted By: SWHeat
Originally Posted By: Junior
In the end my local trans shop talked me out of doing it.
I bet they did. Cha Ching!!! will come much sooner that way.
I seriously doubt it. How many people do you know who have had a temperature related transmission failure in a non towing application? My answer is zero. We 1 ton have service trucks that will run 190-200 all day long on the road towing 6,000lbs. 230 in soft field conditions. None of them have failed a trans in the 200,000 miles we use them before trading.
Originally Posted By: Junior
In the end my local trans shop talked me out of doing it.
I bet they did. Cha Ching!!! will come much sooner that way.
I seriously doubt it. How many people do you know who have had a temperature related transmission failure in a non towing application? My answer is zero. We 1 ton have service trucks that will run 190-200 all day long on the road towing 6,000lbs. 230 in soft field conditions. None of them have failed a trans in the 200,000 miles we use them before trading.
My guess is that the temperatures on those charts are taken in the sump. As said above, time at temperature is what kills oil.
Junior, it is likely that the temperatures you've seen are at the hottest points in the transmission where the fluid is on its way to the cooler. If the fluid was in an area where it was held continuously at those temperatures, you'd have certain transmission failures.
Junior, it is likely that the temperatures you've seen are at the hottest points in the transmission where the fluid is on its way to the cooler. If the fluid was in an area where it was held continuously at those temperatures, you'd have certain transmission failures.
Originally Posted By: Ken2
likely that the temperatures you've seen are at the hottest points in the transmission where the fluid is on its way to the cooler. If the fluid was in an area where it was held continuously at those temperatures, you'd have certain transmission failures.
Yes, I agree.
likely that the temperatures you've seen are at the hottest points in the transmission where the fluid is on its way to the cooler. If the fluid was in an area where it was held continuously at those temperatures, you'd have certain transmission failures.
Yes, I agree.
Well, Gents, this has been enlightening and confirms my thoughts.
The ATF temp/failure charts are not valid in today's world. They need to be relegated to 'urban legend' status. The 'scare' stories may have been true 40 years ago but don't hold up in the light of today's technology.
Transmissions & ATFs are far better engineered to withstand high heat found in today's applications. Things are so good that you can run the [censored] out of them provided you perform the recommended ATF service intervals.
Time at temperature is important. 'Instantaneous high temperatures' are meaningless. The ATF is there to take the heat away (just like the coolant in the engine); be cooled; and recycled to cool again, and again, and again.
The best indicator of fluid temperature is a measurement in the sump as it best represents the 'average operating temperature' of the fluid. The idea of measuring temperatures is to look for 'trends' not absolutes.
In-radiator heat exchangers do a wonderful job at keeping ATF fluids in an temperature range of around 200 to 220F. Or, about the temperature of full open coolant thermostat on a working engine.
If you are going to add a supplemental cooler do so to increase the heat rejection during low speed, heavy load operations. Or, to increase the heat rejection when coming to a crawl, or stop, after a hard pull or high speed run.
Too cool is not good. If you add supplementary cooling, get a cooler with a thermostat to control the flow through the heat exchanger.
Originally Posted By: Junior
Originally Posted By: SWHeat
Originally Posted By: Junior
In the end my local trans shop talked me out of doing it.
I bet they did. Cha Ching!!! will come much sooner that way.
I seriously doubt it. How many people do you know who have had a temperature related transmission failure in a non towing application? My answer is zero. We 1 ton have service trucks that will run 190-200 all day long on the road towing 6,000lbs. 230 in soft field conditions. None of them have failed a trans in the 200,000 miles we use them before trading.
I know of one...mine! Stupid under cooled Dodge Grand Caravan. Yeah, some may say they are a failure prone transmission, granted. However, their failure rate has dropped with the addition of an OEM external cooler in the circuit. Go figure.
Question, do your 1 ton trucks have both water cooled AND air cooled transmission coolers? I would venture...yes. I guarantee you if you ran those temps in the Caravan, they would fail at 85K...hey, some do!
Originally Posted By: SWHeat
Originally Posted By: Junior
In the end my local trans shop talked me out of doing it.
I bet they did. Cha Ching!!! will come much sooner that way.
I seriously doubt it. How many people do you know who have had a temperature related transmission failure in a non towing application? My answer is zero. We 1 ton have service trucks that will run 190-200 all day long on the road towing 6,000lbs. 230 in soft field conditions. None of them have failed a trans in the 200,000 miles we use them before trading.
I know of one...mine! Stupid under cooled Dodge Grand Caravan. Yeah, some may say they are a failure prone transmission, granted. However, their failure rate has dropped with the addition of an OEM external cooler in the circuit. Go figure.
Question, do your 1 ton trucks have both water cooled AND air cooled transmission coolers? I would venture...yes. I guarantee you if you ran those temps in the Caravan, they would fail at 85K...hey, some do!
A rock-solid transmission cooler installation is time-consuming. I had mine mounted on the A/C condenser, then abandoned that for a hard-mounted installation. Much safer and reduced risk of over-cooling the transmission.
And modern passenger cars do have transmissions that over-heat readily. Look at the Honda/Acura transmissions that fail with regularity because of the lack of cooling.
And modern passenger cars do have transmissions that over-heat readily. Look at the Honda/Acura transmissions that fail with regularity because of the lack of cooling.
The Honda ATs fail more due to lack of fluid or material deficiencies.
I would argue that it is better to know the max fluid temperature rather than the bulk average temperature. The same reason why I want to know the coolant temperature max at the thermostat rather than the temp of the coolant in the radiator.
-Yes the service trucks have both oil to coolant and oil to air coolers. I know, some transmissions handle temperature better than other and cooling from 200 to say 175 is certainly going to increase the fluid life if not the whole transmission life. How much probably depends more on the application.
IMO cars are designed to drive up and down the road. As such the cooling packages are designed around this. When you get into the extremes like hot summer stop and go traffic, climbing mountains or towing that is when one gets into trouble. Those applications certainly could benefit from extra trans cooling. For cars that just drive at steady speed on the road, there really shouldn't be much heat generated with the torque converter locked up. Here one may not see much benefit. Just my humble opinion.
If one wants to install an extra cooler, I can't think of too many reason why I wouldn't recommend it.
Back to the original topic. I think todays fluids are more able to handle temperature extremes. The transmission may or may not be able to.
-Yes the service trucks have both oil to coolant and oil to air coolers. I know, some transmissions handle temperature better than other and cooling from 200 to say 175 is certainly going to increase the fluid life if not the whole transmission life. How much probably depends more on the application.
IMO cars are designed to drive up and down the road. As such the cooling packages are designed around this. When you get into the extremes like hot summer stop and go traffic, climbing mountains or towing that is when one gets into trouble. Those applications certainly could benefit from extra trans cooling. For cars that just drive at steady speed on the road, there really shouldn't be much heat generated with the torque converter locked up. Here one may not see much benefit. Just my humble opinion.
If one wants to install an extra cooler, I can't think of too many reason why I wouldn't recommend it.
Back to the original topic. I think todays fluids are more able to handle temperature extremes. The transmission may or may not be able to.
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Quote:
The ATF temp/failure charts are not valid in today's world. They need to be relegated to 'urban legend' status. The 'scare' stories may have been true 40 years ago but don't hold up in the light of today's technology.
I don't have any indication of this notion being supported here ..outside of your statement. Perhaps some minor adjustment in terms of indexing may be in order.
That is, yesteryear's 200F is today's 220F. Everything ages with heat.. just move your line out a tad...
Quote:
Transmissions & ATFs are far better engineered to withstand high heat found in today's applications. Things are so good that you can run the [censored] out of them provided you perform the recommended ATF service intervals.
ATF's and transmission have been engineered to provide consumers with "velvety smooth shifts" over the alleged first ownership cycle. The fluids have been buffered in constituents to enable the "1st owner-less service interval" ..it's the same for coolant and most other service points outside of oil and filters. They also more competent at handling the over engineered nature of the hopelessly complex devices ..that may fail anyway without a fluid related issue just due to that complexity.
Counter to your assertion, I'd say that automatics may have overcome a decade or two of WELL EARNED consumer paranoia and are, perhaps (as in maybe might could be), getting back to a point of reliability that they once had in far more demanding conditions behind higher powered engines of the past. As far as I'm concerned ..the jury is still out. When I see a trans shop with a nearly empty parking lot ...I'll consider it.
Quote:
Time at temperature is important. 'Instantaneous high temperatures' are meaningless. The ATF is there to take the heat away (just like the coolant in the engine); be cooled; and recycled to cool again, and again, and again.
Yes ..ATF is a coolant that "also ran" in the lubrication end of things.
Quote:
In-radiator heat exchangers do a wonderful job at keeping ATF fluids in an temperature range of around 200 to 220F. Or, about the temperature of full open coolant thermostat on a working engine.
Yes ..most often they do. The density of the exchange media (liquid:liquid) trumps air:liquid exchangers for square inches. Does a fine job in a smaller package. It's effectiveness is mostly determined by how well your cooling system is buffered.
YMMV
The ATF temp/failure charts are not valid in today's world. They need to be relegated to 'urban legend' status. The 'scare' stories may have been true 40 years ago but don't hold up in the light of today's technology.
I don't have any indication of this notion being supported here ..outside of your statement. Perhaps some minor adjustment in terms of indexing may be in order.
That is, yesteryear's 200F is today's 220F. Everything ages with heat.. just move your line out a tad...
Quote:
Transmissions & ATFs are far better engineered to withstand high heat found in today's applications. Things are so good that you can run the [censored] out of them provided you perform the recommended ATF service intervals.
ATF's and transmission have been engineered to provide consumers with "velvety smooth shifts" over the alleged first ownership cycle. The fluids have been buffered in constituents to enable the "1st owner-less service interval" ..it's the same for coolant and most other service points outside of oil and filters. They also more competent at handling the over engineered nature of the hopelessly complex devices ..that may fail anyway without a fluid related issue just due to that complexity.
Counter to your assertion, I'd say that automatics may have overcome a decade or two of WELL EARNED consumer paranoia and are, perhaps (as in maybe might could be), getting back to a point of reliability that they once had in far more demanding conditions behind higher powered engines of the past. As far as I'm concerned ..the jury is still out. When I see a trans shop with a nearly empty parking lot ...I'll consider it.
Quote:
Time at temperature is important. 'Instantaneous high temperatures' are meaningless. The ATF is there to take the heat away (just like the coolant in the engine); be cooled; and recycled to cool again, and again, and again.
Yes ..ATF is a coolant that "also ran" in the lubrication end of things.
Quote:
In-radiator heat exchangers do a wonderful job at keeping ATF fluids in an temperature range of around 200 to 220F. Or, about the temperature of full open coolant thermostat on a working engine.
Yes ..most often they do. The density of the exchange media (liquid:liquid) trumps air:liquid exchangers for square inches. Does a fine job in a smaller package. It's effectiveness is mostly determined by how well your cooling system is buffered.
YMMV
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