Another External Tranny Thread, Lets put the question to rest

[Thorgan112]

So before I have 55 responses telling me to search, let me just say I have. I just spent the last hour reading this http://www.toyota-4runner.org/3rd-gen-t4rs/107129-transmission-cooler-pass-radiator-not-pass.html#post966885 and a few other threads about tranny coolers. My question is simple. Has anyone (preferable in the east, for climate reasons) who has installed a tranny cooler and bypassed the stock radiator had an issue with their transmission afterwards?

There is plenty of arguing and speculation as to whether the radiator actually helps warm the tranny fluid as well, but I have not seen one person write a negative review on an external cooler. All I can find is people who have not installed one complaining (unfortunately most of their arguments make sense to me) but still, no real evidence is available, so please if you know of an incident where a external cooler "destroyed" or hindered performance of a transmission please speak up! I would like to try and truly figure out this debate.

 

[Robb235]

Have had no problems with the trans cooler bypassed, using the external cooler only.

 

[txbonds]

Used my 97 to pull a 6x12 dual axle trailer 125 miles last week and the highest temp reading I got on my tranny was 180 degrees. Most of time it was closer to 170 and under. The temp on the return side of the cooler was down between 95 and 105 at the same time.

My engine temp was 184 and my tranny cooler bypasses the radiator.

I'm in north FL and was driving to S Ga and outside temp was high 80's


Point being that if I went through the radiator my trans temp would have been higher.



EDIT: I'm using a B&M 70264 cooler.
http://www.summitracing.com/parts/bmm-70264



.

 

[Doc2012]

I put an external on and bypassed my stock.

Moved a friend of mine from Mass to NC, and had no problems out of it at all.

Bypass the rad. You'll be glad you did.

 

[Kenworth]

I did wife 99 at 97000 miles 163000 now no issues just flushed trans fluid as preventive mainance,external cooler is piece of mined

 

[allwheeldrive]

Yup, bypass the crappy radiator one. You'll never worry about the radiator leaking into your trans, and there's no downside to an external cooler. I'm in Ohio and my truck performed flawlessly last winter even with the subzero temps. I just used an old rx350 trans cooler that I scored from work.

 

[slides]

no issues, its nice having the internal bypass though. tranny does warm up fast with external cooler

 

[jgue467]

Have had no problems with the trans cooler bypassed, using the external cooler only.

same here, but yeah of course built in factory cooler will both warm up tranny faster & keep it there. If u tow up pretty good grades turning OD off really lowers trans temps. Either get the better coolers w/"cold fluid" valving or cover it up in winter. Never heard of damage from cold fluid, but perhaps not as efficient? Luck!

 

[Brique]

Thanks for starting this thread. I've been thinking about this lately, too. Everyone who replies, would you please also tell us what brand/model cooler you're using? For those of you who have responded already, would you mind editing your post and adding that? I think it would be a huge help.

Thank you!

 

[theizzardking]

so please if you know of an incident where a external cooler "destroyed" or hindered performance of a transmission please speak up! I would like to try and truly figure out this debate.

water forms in ATF if ran cold for short trips..... you wouldn't pour water into your transmission would you?


that's worst case scenario, winter time/short trips....repeatedly...

That said.
I'd think for the vast vast majority of people it'd be ok.... but there is such a thing as your trans running too cool...or more like the fluid....

an external cooler may not be ideal for people living in cold climates who frequently make short trips....beyond that i see no reason not to recommend an external transcooler to most anyone....

 

[Koch13351]

I have a factory 2000 toyota tundra external cooler on mine. It fits right in and looks stock.

 

[Millerad1651]

I installed a B&M 60028 almost three years ago completely bypassing the radiator. I've towed boats, gone off-road for hours at a time, and had to drive in -30 weather. I've never had a hiccup. Tranny fluid still looks good and it shifts just like it should.

 

[Mgyver1]

My '02 Tacoma (for sale btw) is bypassed and has been for about 25,000 miles. My new to me '00 4Runner is bypassed too. Both using a Trucool 4589, and I just did my buddy's '00 4Runner using the same cooler. My and my buddy's 4R use the same method that AjonesNV did the write up on. In case you couldn't tell I'm a proponent of it.

 

[LittleCaesar]

B&M 70264; I prefer that it is small in length but thick as well as having an LPD that begins to open at 170F and completely opens at 180. I do have a spin on filter in line with it, located before the cooler.

 

[AlphaEcho2k5]

I have had the Tru Cool 4590 installed for over a year without issue. I installed it while stationed at Fort Bragg, NC and even up here in Cheyenne, WY where I see temps as low as -20 & -30 it doesn't skip a beat.

 

[Robb235]

B&M 70264; I prefer that it is small in length but thick as well as having an LPD that begins to open at 170F and completely opens at 180. I do have a spin on filter in line with it, located before the cooler.

Just curious, how often do you change that filter? Where do you get replacements?

 

[7echo]

I have a factory 2000 toyota tundra external cooler on mine. It fits right in and looks stock.

Are you by-passing? I have one of these but it seems a little small. Got any temps to report?

 

[Amirocassar]

I know this has probably been asked before but I will anyway. Is the trans cooler really of any benefit if you don't do much towing? I don't ever do any towing or heavy loads, so even without towing am I at a large risk for the milkshake? And all in all how much does it cost to do this? All the parts included if anybody could give me an estimate. Thanks a ton!

 

[txbonds]

I know this has probably been asked before but I will anyway. Is the trans cooler really of any benefit if you don't do much towing? I don't ever do any towing or heavy loads, so even without towing am I at a large risk for the milkshake? And all in all how much does it cost to do this? All the parts included if anybody could give me an estimate. Thanks a ton!

Milkshake is due to a corrosion failure inside the radiator that allows two liquids to mix, doesn't really matter if towing or not. More of an age thing.

B&M 70264 kit is only about $75 or less and can be installed at home. A good shop would probably do it for $150 or less but I'm just guessing.

No reason not to do it given cheap price. On my 97 I did new Koyo radiator and bypassed cooler.

 

[98OzarksRunner]

I used a Hayden cooler on my last 2 4Runners. I live in SW Missouri, where we get hot summers and cold winters too (though not that cold - we do get a few days when the highs are less than 10 deg). My 98 currently has 55K with the cooler, and my 02 has 40K with one. No problems at all. It doesn't take long for the fluid to warm up on cold days (at least as far as I can tell - the transmission shifts at higher RPM when it's cold, and it doesn't do that very often, or for very long - a mile or two of driving at most on really cold days). The transmission (specifically the torque converter) probably generates a lot more heat to warm the fluid than the engine coolant in the radiator does (and probably warms it up faster too).