quicksilvr
New member
Sounds like you got it right. I think if I ever did any serious slow-speed off roading I'd need a dedicated fan on my cooler as well.
Looking forward to seeing the results after you install the fan.
ATF Temp-How hot is too hot?
- Thread starter domstriker
- Start date
Sounds like you got it right. I think if I ever did any serious slow-speed off roading I'd need a dedicated fan on my cooler as well.
Looking forward to seeing the results after you install the fan.
What transmission temperatures are you guys running when wheeling?
I bought a 2000 SR5 in December and it had an external tranny cooler installed already.
Tonight I got the scangauge II ATF up to 230 twice when wheeling in the snow (I was going uphill both times with lots of wheel spin).
Each time, I stopped and let it cool down below 200 before starting again. I'm guessing 230 is too high or could I have pushed it more before worrying?
I was planning on changing the tranny fluid with synthetic within the next couple weeks anyway, but now I'm thinking I should get a fan for the tranny cooler, or maybe just replace it altogether?
Does anyone have any updates on their fans?
I bought a 2000 SR5 in December and it had an external tranny cooler installed already.
Tonight I got the scangauge II ATF up to 230 twice when wheeling in the snow (I was going uphill both times with lots of wheel spin).
Each time, I stopped and let it cool down below 200 before starting again. I'm guessing 230 is too high or could I have pushed it more before worrying?
I was planning on changing the tranny fluid with synthetic within the next couple weeks anyway, but now I'm thinking I should get a fan for the tranny cooler, or maybe just replace it altogether?
Does anyone have any updates on their fans?
turbodudey2
New member
During hard low speed wheeling my temps are 125 - 145 degrees. (with ambient temps around 50 degrees)
Wheeling in the snow the last couple weeks I've seen up to about 145 degrees as well.
Personally I don't like to see trans temps above 200 degrees. And with the cooler I'm using the max temps I usually see are around 180 degrees (long uphills on the highway).
quicksilvr
New member
Note that turbodudey is getting his trans temp from an analog gauge, being fed from the temp probe by his remote filter. Those temps are considerably cooler than what a SGII reads.....so his 145 is more like a 165 read from a SGII.
BTO
Member
It's been posted here on a different thread that wheeling tranny temps too high can be caused by improper mounting of the cooler. It should be mounted flush with the AC condenser directly in front of the fan. If not then you are relying on air movement at speed which you won't get much of while wheeling.
Sorry for resurrecting this old thread (but hey, at least I'm using the search!)..
Can anyone comment on the statement above? I just mounted mine with about 1" gap from the AC condenser; I went for a drive and then felt the tranny cooler and it felt hot, "almost" too hot to touch. I figured that should be expected, if the operating temp got to 180F?
kball
New member
He said 180 not 280..?
I first mounted my cooler with brackets away from the condenser at least 2 inches. Then when I was doing my timing belt I figured it was a good time to move it right up against the condenser. I had a temp gauge on it for before and after temps and honestly I didn't see much of a difference.
In regular city driving, maybe 10 degrees on average. I've still seen temps go way above 200 during slow up hill or off road driving which, against popular opinion here, I don't think is all that bad for short durations.
If you want the lowest possible temps, mount it up against the condenser but you'll have to move the rad out of the way unless you want to zip tie through both and take the chance on pulling/ bending them together.
I first mounted my cooler with brackets away from the condenser at least 2 inches. Then when I was doing my timing belt I figured it was a good time to move it right up against the condenser. I had a temp gauge on it for before and after temps and honestly I didn't see much of a difference.
In regular city driving, maybe 10 degrees on average. I've still seen temps go way above 200 during slow up hill or off road driving which, against popular opinion here, I don't think is all that bad for short durations.
If you want the lowest possible temps, mount it up against the condenser but you'll have to move the rad out of the way unless you want to zip tie through both and take the chance on pulling/ bending them together.
I don't have a scanguage; I just felt the tranny cooler and it was too hot to touch. That's obviously not a very objective measurement, but was wondering what others felt about that as a "gauge." Should it be too hot to touch or is that a bad thing? I haven't seen anyone talking about this cooler being insufficient for anything, and I have no reason to believe I didn't mount it correctly. I guess I'm just being overly cautious. Perhaps I should invest in a Scangauge to satisfy my curiosity.
mmml4
New member
IIRC about 110 degrees is going to be the limit your hand can tolerate.
the great him
Elite Member
ok so im running dual coolers one is the B&M 70264(the larger of the two B&Ms) the other is a perma-cool & has a 10" electric fan. i see temps on normal day to day driving of about 150-180 (thats with two big 7" off road lights on my bumper and a winch control pack "blocking" the air flow. both of my coolers are sucked up tight to the AC condenser and attached via zip-ties all the way through the rad. see my build for details on this- http://www.toyota-4runner.org/3rd-gen-t4rs/105400-rescue-runner-build-thread.html , anyhow i would not run a single cooler smaller than the 70264, as i had serious over heating issues with that cooler, both in traffic and on hills, there were several times i saw temps over 250, even in the snow at below freezing temps. the second cooler has helped a lot. i am also running my temp sending unit before the coolers so im reading the highest possible temps, as it comes out of the tranny.
there are some draw backs to bypassing the radiator. air to liquid cooling does not work as well as liquid to liquid cooler. so if you ran your factory trans cooler along with the external cooler you would see more stable temps, but they would be higher -roughly the same temps as the coolant (around 180-190 constantly). and you would still run the risk of the pink milkshake. for that reason alone i bypassed all together. also i am running over sized e rated tires(heavier and requires more effort to turn and keep turning), full skids(add more weight and dont allow for the aid of airflow over and around the trans to help cool), sliders (more weight), and a bumper with winch(again more weight and blocks restricts airflow moderately). i have seen temps once sense i did the second cooler spike over the 285(where our trans temp idiot light is triggered to come on), and i just stopped and opened my hood up and let the motor run, and waited for it to cool down, but this was low speed crawling in the heat of the day in direct sun with big loads on the trans and basically no airflow what so ever -again crawling. one other time i saw temps over 250, but that was after climbing a long hill(gained over 3800' in elevation in less than an hour with the last part of that on old forest service roads at speeds under 20mph... is soon as i cool i found a snow patch and ran my truck up into it to help cool -skid plates prevented that from doing much good, so i opted to go drive it into the lake to cool things off, this worked much better and within 2min i was down to around a temp of 120. but again this was in the dead of summer in northern california around chico/paradise/lake almanor. it was ever bit of 95 out, and i was loaded down with a weeks worth of camping gear and food, spare parts and tools for wheeling -i tipped the scales at 5600lbs so i was giving my trans a good workout even with those dual coolers.
i personally think that anyone running a single cooler even in a temperate climate should not use anything less than the larger 70264 cooler. if you do, you are asking for troubles as temps can easily rise fast. -temps will rise faster than they will fall, and the hotter the temps get the easier it is for them to continue to heat up think of it as a teeter-todder, say 150 is center, the further you go out from the center the faster the end will dip, same with the heat, the higher you go with your temps the faster they will be able to rise. -it might take 10min to go from 150-180, but that 180-210 might only take 4min... -this is given that you keep the same driving style and same loads on the vehicle constant.
there are some draw backs to bypassing the radiator. air to liquid cooling does not work as well as liquid to liquid cooler. so if you ran your factory trans cooler along with the external cooler you would see more stable temps, but they would be higher -roughly the same temps as the coolant (around 180-190 constantly). and you would still run the risk of the pink milkshake. for that reason alone i bypassed all together. also i am running over sized e rated tires(heavier and requires more effort to turn and keep turning), full skids(add more weight and dont allow for the aid of airflow over and around the trans to help cool), sliders (more weight), and a bumper with winch(again more weight and blocks restricts airflow moderately). i have seen temps once sense i did the second cooler spike over the 285(where our trans temp idiot light is triggered to come on), and i just stopped and opened my hood up and let the motor run, and waited for it to cool down, but this was low speed crawling in the heat of the day in direct sun with big loads on the trans and basically no airflow what so ever -again crawling. one other time i saw temps over 250, but that was after climbing a long hill(gained over 3800' in elevation in less than an hour with the last part of that on old forest service roads at speeds under 20mph... is soon as i cool i found a snow patch and ran my truck up into it to help cool -skid plates prevented that from doing much good, so i opted to go drive it into the lake to cool things off, this worked much better and within 2min i was down to around a temp of 120. but again this was in the dead of summer in northern california around chico/paradise/lake almanor. it was ever bit of 95 out, and i was loaded down with a weeks worth of camping gear and food, spare parts and tools for wheeling -i tipped the scales at 5600lbs so i was giving my trans a good workout even with those dual coolers.
i personally think that anyone running a single cooler even in a temperate climate should not use anything less than the larger 70264 cooler. if you do, you are asking for troubles as temps can easily rise fast. -temps will rise faster than they will fall, and the hotter the temps get the easier it is for them to continue to heat up think of it as a teeter-todder, say 150 is center, the further you go out from the center the faster the end will dip, same with the heat, the higher you go with your temps the faster they will be able to rise. -it might take 10min to go from 150-180, but that 180-210 might only take 4min... -this is given that you keep the same driving style and same loads on the vehicle constant.
NateMob
New member
B&M lists on their own website not to use anything less than the 70266 when bypassing the radiator cooler all together. Its harder to mount but doable, its what i run and i dont have to worry about pink milkshake ever!
First page 6th bullet down.
http://bmracing.com/wp-bnmcont/uploads/bm_cooler_techdoc.pdf
First page 6th bullet down.
http://bmracing.com/wp-bnmcont/uploads/bm_cooler_techdoc.pdf
All this is good info. Here's a pragmatic question... Higher ATF temps means it won't last as long as it would with lower temps. So if the truck is used lightly, say, 5000 miles a year, and you do a drain/fill every 2-3 years, would that be essentially "enough" of prevention? Is this kind of a different way to skin the cat? I installed a 70268 and bypassed the radiator. I do tow a 2200lb trailer/boat combo periodically, so I am definitely interested in better cooling. I might install another one in series or just make sure I monitor the condition of my ATF more frequently.
the great him
Elite Member
do you have a temp gauge? i dont mean to sound like a prick, but my first thoughts and inclination was to call you a fool, for towing with the smaller of the two coolers... i wouldnt even tow with a single large cooler, but thats just me. i have towed over 9000lbs with my runner, it was basically an emergency and i took it super easy. but i also flushed my trans right after that and my fluid smelled and looked ok but i wasnt gonna trust it -yes i had a brake controller and trailer brakes on both axles as well as air bags. i would be changing fluid more often than that personally but thats me. an ounce of prevention is worth a pound of repairs. consider all the extra weight i have on my rig, bumper with winch +220lbs, sliders +80lbs, skids +80lbs, so there you have 380lbs extra, call it 500lbs to be generous and account for the lack of air flow, thats no where near the 2200lbs you are pulling. i have two large coolers, you have one small cooler, and i still see temps of 150-180 in daily driving, so just think of what you could be seeing while towing. -also remember the idiot light on the dash does not come on until at least 285* if i remember correctly
like i stated above air-liquid coolers are not as efficient as liquid-liquid, your radiator will help regulate the temps, and keep them from spiking, but it will also have them at a much higher temp constantly(around 180-190) and you run the risk of over heating your trans if you overheat the motor -id personally keep the two separate for this reason as well as the pink milkshake. i dont think your little 268 cooler will even be able to keep up with your trans as well as the stock set up unless you are in a constant head wind on a 70* or cooler day. especially if you are in traffic. i think that two 268 are better than one 264, and i really think thats what you need minimum, for towing. the issue is i nor anyone here can tell you how good your tranny fluid is really by looking at it(unless its dark brown and smells like toast -then it is toast...) but it can be breaking down and still be bright red or dark red... what im saying here is by the time you look at it and see that "oh gee, my trans fuild is needing to be changed..." some of the damage has already happened and your trans life has been shortened. dont you think it would be better to air on the side of caution and not play with fire? i find when i play with fire i always end up getting burned and its not fun. id just double up on the cooler and install a trans temp gauge and call it good. if with the dual trans coolers you find you are still exceeding the 200* mark regularly or more than 20% of the time while driving, then id go for a dual 70264 set up. you are not gonna over cool these things. B&M has a built in thermostat type of system that allows fluid that is too cold to bypass the cooler untill it warms up enough to need the cooler. guys are like oh, 135* is too cool, yeah well take some oil or even water thats heated to 135 and poor that on your hand, and tell me that(dont do it you will burn yourself trust me -you can get a 3 dergree burn from water at 140*, oil will not simply run off and evaporate like water) atf at 120* is plunty warm for the trans to work properly. and their is no harm in 150-180 imo -the stock trans cooler will only cool down to probably 160 at the lowest -considering that its at the bottom of the radiator and the hot coolant comes in at the top, heat rises and it has all that area to be cooled by the air flow before it comes down low into the lower portion of the radiator... then you have the heat of the trans fluid that is being cooled. id guess that you could take another 10* out of the radiator allowing it to be more efficient by bypassing the radiator with the ATF and going stand alone.
im no engineer or anyone who has spent hours and hours researching this stuff or written papers on this ect. just have some experience in the automotive industry -worked for a couple shops, and a dealer and using my personal experiences and observations to guide my thoughts and ideas. i am by no means gonna tell you that i am 100% correct and if you dont listen to me or my advice doom and gloom will come to you and your runner, no, but i dont want to see that either and so i always play cautiously and try to stay safe. -i think a lot of guys on here are in a false sense of security with the coolers they have, especially the ones without temp gauges or a way to monitor temps ect. i know some guys running just the one cooler and they say its working for them and their temps are just fine... idk not saying they are a liar or that i dont believe them, but if it was me id rather be safe than sorry.
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