I think 200F is pretty normal, but probably depends on the trans. My new Ford 10 Speed runs over 200F at freeways speeds all the time.
How hot is too hot for Mercon V ATF?
- Thread starter R18Civic
- Start date
My 2015 Ford P/U with the 6 speed get hotter that that on a hot day.
I would discuss it with your rebuilder first. You don’t want to void any warranty it may have.
Are you doing a before & after comparison, or did you only start reading temperatures after the rebuild?
My 2001 Silverado has the factory trans cooler and I have seen temps in the 190s during hot weather.
Whether the fluid is right for your trans would be something to take up with the rebuilder.
My 2001 Silverado has the factory trans cooler and I have seen temps in the 190s during hot weather.
Whether the fluid is right for your trans would be something to take up with the rebuilder.
My ScanGuage has shown the MGM’s ATF as high as 200F, so I don’t think 180F will hurt anything. I can’t understand why someone would put Mercon V in a Dex VI application-Dex 6 is a low viscosity ATF, V is not. Dexron 6 is the replacement for Dex 3 and priors, but Dexron V really isn’t superseded by anything (or I would use it, V is only a blend, VI is full synthetic).
For older units, this may be true. These days lots of units operate north of 190 on a normal day and up to 250 when really working hard. They're built to deal with the higher temps and so are newer fluids.
The 6R80 in my wife's rig has an internal thermostat that doesn't even allow fluid to flow through the cooler until it hits 192f.
I would use what is recommended, not what the rebuilder had on hand. I would say nothing to your tranny rebuilder.
Unless you have an additional air to oil cooler, your trans is typically running at the engine coolant temp unless it is very cold outside. So I wouldn't worry about that.
As far as fluid, put in some Allison TES-295 spec and never worry about it again.
As far as fluid, put in some Allison TES-295 spec and never worry about it again.
I believe that elevated temps harden the rubber seals vs actually damage the fluid .
i swore i read that trans temps can exceed 600* under heavy loads, during severe use (in certain areas), and the thermal chemicals added were to help protect the fluid during high spikes to keep it form breaking down. this fluid is whats cooling the hot part for a milisecond, or in a stream.
and if your trans fluid goes through your radiator for cooling..........most automotive engines are in the 212* thermostat range which the radiator will be cooler but you get the point. if the fluid is going through a radiator/cooler thats 180ish for cooling, then the fluid must be capable of getting hotter or why else would they send it through the radiator which is 180-200*
so that takes us back to your original question, how hot is too hot? looks like we need to do a little research to see what temps mercon V is capable of withstanding......
i would assume during normal operating conditions, your temps are probably fine, and I bet.......... even if you change the fluid, your not going to see much difference if any............and if oil seals, valve cover seals, plastic intake manifolds, plastic valve covers, plastic grommets, paint, copper, tin lead, aluminum, iron..... whatever........... hold up fine on an engine that gets to the 212* "normal operating temp" and are just fine........... i bet the same seals, plastic, rubber, etc.....are just fine on the auto trans.
mercon is just a trademark name from ford motor company for their auto fluid. dextron is the trademark name of almost the exact same fluid from GM.......its like pennzoil vs valvoline......engine oil, they are pretty much similar but yet, have minute differences in chemical makeup.......and mercon V is just the last version of that fluid which ford stopped making back in 07...........thats right, 07. so if your buying mercon v from good ol ford..........well according to what ive read, as of this year..........its fluid thats been sitting in a bottle for the last 15 years. a little past its cheduled recommended change interval.................... just kidding........ well, about the change interval.
and dextron VI is the latest version of atf from good ol GM...........it supercedes their previous versions........... is it better than V? well I'd assume being generation iv, should be better than generation v?? in fact, GM and FORD went together to make fluids......and i think transmissions.......
and just for laughs...........i thought this was very funny.......copy and pasted from DEXTRON wiki
IMPORTANT: The quart containers of Dexron ULV must be shaken to stir up the additives before pouring. This fluid is not backward compatible with any previous fluids.
This fluid was first used in the following transmissions:
and if your trans fluid goes through your radiator for cooling..........most automotive engines are in the 212* thermostat range which the radiator will be cooler but you get the point. if the fluid is going through a radiator/cooler thats 180ish for cooling, then the fluid must be capable of getting hotter or why else would they send it through the radiator which is 180-200*
so that takes us back to your original question, how hot is too hot? looks like we need to do a little research to see what temps mercon V is capable of withstanding......
i would assume during normal operating conditions, your temps are probably fine, and I bet.......... even if you change the fluid, your not going to see much difference if any............and if oil seals, valve cover seals, plastic intake manifolds, plastic valve covers, plastic grommets, paint, copper, tin lead, aluminum, iron..... whatever........... hold up fine on an engine that gets to the 212* "normal operating temp" and are just fine........... i bet the same seals, plastic, rubber, etc.....are just fine on the auto trans.
mercon is just a trademark name from ford motor company for their auto fluid. dextron is the trademark name of almost the exact same fluid from GM.......its like pennzoil vs valvoline......engine oil, they are pretty much similar but yet, have minute differences in chemical makeup.......and mercon V is just the last version of that fluid which ford stopped making back in 07...........thats right, 07. so if your buying mercon v from good ol ford..........well according to what ive read, as of this year..........its fluid thats been sitting in a bottle for the last 15 years. a little past its cheduled recommended change interval.................... just kidding........ well, about the change interval.
and dextron VI is the latest version of atf from good ol GM...........it supercedes their previous versions........... is it better than V? well I'd assume being generation iv, should be better than generation v?? in fact, GM and FORD went together to make fluids......and i think transmissions.......
and just for laughs...........i thought this was very funny.......copy and pasted from DEXTRON wiki
IMPORTANT: The quart containers of Dexron ULV must be shaken to stir up the additives before pouring. This fluid is not backward compatible with any previous fluids.
This fluid was first used in the following transmissions:
- 2017 10L90 10-Speed Automatic Transmission
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Mercon V is still licensed for sale by Ford, so any you buy today will most certainly not be 15 years old.
No 'T' in Dexron, either
No 'T' in Dexron, either
Well it was from the "DEXTRON wiki" as jetski247 notedMercon V is still licensed for sale by Ford, so any you buy today will most certainly not be 15 years old.
No 'T' in Dexron, either
Add a cooler to it and I wouldn't worry too much about which fluid really but if you want the dex VI run it. Cooler to me would be more important, if it has one already- put a bigger one in it.
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