Transmission cooler question

[bay_area4runner]

I'm planning to get a transmission cooler for my rig. I just don't know what to look for or how to choose one.

I've seen threads about certain ones but how do you choose which is the one for your ride? Can anyone give me a heads up

 

[mtbtim]

Many have found the B&M 70264 to be a good choice. That's the one I put on my rig. Some say bypassing the stock trans cooler in the radiator is the way to go while others keep the stock cooler in the system and run it in-series.

Many that have bypassed are starting to find a bypassed system isn't cutting it to keep your trans temps down when you're really pushing your rig hard (towing, mountain driving, wheeling). Do the research and choose the route you think is best for you.

And, here's a video you can use:

<iframe width="560" height="315" src="https://www.youtube.com/embed/2nVbwe2t2T8" frameborder="0" allowfullscreen></iframe>

 

[Kotrin]

I've completely bypassed mine from the radiator and run the B&M upfront of my current coolers that do radiator, power steering and etc. I did a overland trip fully loaded in 95 degree heat. I did 4 mile climb of 5k elevation change and by using the transmission auto in 1st and 2nd I was able to keep the transmission under 215 for the entire climb and my entire trip I think it hit 230 once and that was leaving od on and me not thinking.

So from personal experience I have full faith in mine to keep mine cool over mountain passes and more. Now I do change my fluid every 30k just from paranoia and wanting to make it last as LONG as I can (and reliable).

 

[mtbtim]

I've completely bypassed mine from the radiator and run the B&M upfront of my current coolers that do radiator, power steering and etc. I did a overland trip fully loaded in 95 degree heat. I did 4 mile climb of 5k elevation change and by using the transmission auto in 1st and 2nd I was able to keep the transmission under 215 for the entire climb and my entire trip I think it hit 230 once and that was leaving od on and me not thinking.

So from personal experience I have full faith in mine to keep mine cool over mountain passes and more. Now I do change my fluid every 30k just from paranoia and wanting to make it last as LONG as I can (and reliable).

I use 1st and 2nd for engine braking lots, but I've rarely used it when climbing hills. In the owners manual it says, "Do not continue hill climbing or hard towing for a long time in the "2" or "L" position. This may cause severe automatic transmission damage from overheating. To prevent such damage, "D" position should be used in hill climbing or hard towing."

I've used my gears like you have when climbing hills in the past with other vehicles but I haven't done it with my 4runner because of what I read in the owners manual.

Anyway, that's good you haven't seen super high temps with your bypassed system. With my in-series set-up, the highest I've seen is around 210 which was from climbing a long steep grade loaded down with gear. I just did a 3000+ mile trip and never got it over 200.

But, what a bypassed system can't do that an in-series system can is heat up the trans fluid to an optimum operating temperature quicker since the trans cooler is bathed in the hot coolant. Those that operate in freezing conditions for many months during the year should really give extra thought to the bypass choice. The FSM says normal operating temperature for the trans fluid is 158-176. Run the transmission too cool for too long and moisture builds inside which isn't good. I think most worry about running too hot, but running too cold isn't great either from what I have read.

 

[bay_area4runner]

Thanks for the info guys but how do I know which cooler to use? I want to bypass mine too but I'm not sure how to choose one, specially because everyone puts on different models

 

[mtbtim]

I know you said you already made up your mind to bypass, but here's a couple threads I started with some good discussion:

http://www.toyota-4runner.org/3rd-gen-t4rs/217667-trans-temps-bypassing-using-external-cooler.html

http://www.toyota-4runner.org/3rd-g...sion-temperatures-how-relates-life-fluid.html

The reason why I'm hammering you with info is because I believe many run to the bypass decision due to the fear of the pink milkshake and don't do enough research for the way they intend on using their rig.

Ok, I'll shut up now.

 

[Jayjayb96]

I know you said you already made up your mind to bypass, but here's a couple threads I started with some good discussion:

http://www.toyota-4runner.org/3rd-gen-t4rs/217667-trans-temps-bypassing-using-external-cooler.html

http://www.toyota-4runner.org/3rd-g...sion-temperatures-how-relates-life-fluid.html

The reason why I'm hammering you with info is because I believe many run to the bypass decision due to the fear of the pink milkshake and don't do enough research for the way they intend on using their rig.

Ok, I'll shut up now.

Ive read that some people ran two tranny coolers in series and also bypassed the radiator. Do you think adding a 2nd cooler would help?

 

[mtbtim]

Ive read that some people ran two tranny coolers in series and also bypassed the radiator. Do you think adding a 2nd cooler would help?

Yes, running two coolers will definitely help lower the temps, but at the same time, keep the trans fluid running too cool in colder weather. If it was just a case of running too hot, I'd probably have chosen to run a big cooler and bypassed the radiator cooler too. But like I've already stated, trans fluid has an optimum operating temperature range and running too cool will allow moisture to build inside the transmission which isn't good.

Think of it this way. Why do we have a thermostat for the engine? It's because without it, the engine would take longer to heat up to an optimum operating temperature. The thermostat keeps the coolant running through the engine until it reaches 180 degrees and then opens to cycle the coolant through the radiator to be cooled and returned to the engine. By the same token, the stock trans cooler in the radiator shortens the time it takes the trans fluid to reach optimum operating temperature because the cooler is bathed in the hot coolant and transfers heat to the trans fluid via conduction.

I did a lot of reading on the subject before making my choice and I'm just suggesting others do the same.

 

[Kotrin]

I use 1st and 2nd for engine braking lots, but I've rarely used it when climbing hills. In the owners manual it says, "Do not continue hill climbing or hard towing for a long time in the "2" or "L" position. This may cause severe automatic transmission damage from overheating. To prevent such damage, "D" position should be used in hill climbing or hard towing."......

So it says overheating. Never experienced this as I controlled rpms vs cooling by going about it this way. I use my ScangaugeII to monitor this. As far as warming it up I understand this and monitor when it has been cold and noticed this. One reason I do my 30k fluid and keep an eye on it. Also what is defined as "long time". I feel this is one of those areas again where it was tested and it is a area of monitor,care and resting it on long climbs is your friends.

I feel that sometimes things I say don't get understood the way I was trying to convey them, so in that regards I fully understand my 4runner and did not do any damage to it and keep my vehicle running tip top and able to monitor it.

Now all of us have different experiences and each vehicle is unique and I hope personal experience gives you some insight on each individual knowledge and form your own valued hypothesis / idea.

Good luck and seach is all of our friends.

 

[stivine6]

Just literally finished up my install on my B&M cooler. I went with the 70268 model and it fits really well behind the grille. I would however get at least 10" of transmission hose and give the routing some slack. I also used some left over hose to insulate any sharpe edges or areas where the hose can wear from abrasion.

Most difficult part was trying to get the transmission hose off the metal line.

No more worrying about milkshake!

 

[jgue467]

Thanks for the info guys but how do I know which cooler to use? I want to bypass mine too but I'm not sure how to choose one, specially because everyone puts on different models

If going by-pass (no oem trans cooling) I'd select a larger rather than smaller cooler (assuming you measure the area we have to work with).

As mentioned by-passed really requires a fan in 90+ type weather mostly during stop/go and perhaps some slow going off-roading. Acceleration is where the heat piles up, once up to speed cruising steady it drops like a rock. So what you want to control are the peaks.

Mine has been by-passed over 100k miles and doing just fine BUT if i had to do it again, I'd go OEM radiator. It simply works best, can anyone dispute that? :cowboy:

 

[SpidermanGeek]

by-passed 70268 here. Mine's right up against the AC condenser so it gets a good air draw from the engine fan.

I ultimately decided to go by-passed 70268 because I have no clue how old the radiator is (and still seems in to good a shape to replace at this time), and because of the fact that I don't tow, I don't keep any gear in the vehicle, and I'm in Canada, so our winters can become quite cold at times.

I have only seen my trans temps climb to 180F once, and that was on our hottest day of the year this summer where I was in some stop and go traffic for about a half hour. Otherwise, my trans temps haven't really gone over 160F on average.

The SF Bay area (from my recollection) doesn't get insanely hot (at least not consistently), but is a hilly area. So you have to evaluate what it is you plan on doing with your rig. I still advocate by-passing because I just like to keep things segregated like that, but you may want to consider the bigger 70264 and maybe a single electric fan to push air through the cooler. The good thing about the SF Bay area is that you don't really need to worry about extreme cold weather either.

I think there are pros and cons to every setup that has been explored on T4R, but no matter what you chose, I don't think there's really a "bad" choice.

First thing to look at is whether or not your rad is due to be replaced. If it is, my suggestion would be to just replace, do trans fluid flush and not worry about a thing for another 30-50K miles. That's probably your cheapest, most headache free option.

If you wanna through a bit more money at your rig for slightly heavier duty application, do the above, but install a 70268 in series (non-bypassed).

If you're adamant about bypassing, then don't worry about the rad (if it's still in good shape) and get yourself a 70264 or a pair of 70268's maybe. Your options start to become limitless at this point.

 

[mtbtim]

So it says overheating. Never experienced this as I controlled rpms vs cooling by going about it this way. I use my ScangaugeII to monitor this. As far as warming it up I understand this and monitor when it has been cold and noticed this. One reason I do my 30k fluid and keep an eye on it. Also what is defined as "long time". I feel this is one of those areas again where it was tested and it is a area of monitor,care and resting it on long climbs is your friends.

I feel that sometimes things I say don't get understood the way I was trying to convey them, so in that regards I fully understand my 4runner and did not do any damage to it and keep my vehicle running tip top and able to monitor it.

Now all of us have different experiences and each vehicle is unique and I hope personal experience gives you some insight on each individual knowledge and form your own valued hypothesis / idea.

Good luck and seach is all of our friends.

I do think you're fine holding your trans in a lower gear while climbing especially since you monitor your trans temps. Knowing what I know now, I don't even understand why holding it in a lower gear would potentially cause overheating.

What the owners manual should have hit upon is telling people to turn off the overdrive to keep the trans temp down when climbing steep grades and your speeds are 60mph or less. Adding the external trans cooler has definitely helped keep my trans temps down but learning that turning the overdrive off can drop the temps by another 20+ degrees was huge.

 

[01thunder]

go to a yard and have some fun looking around for one. i put one in my truck from an explorer, $7.

 

[3bears]

I went with the 70264 and bypassed the radiator

while I did have concerns with it being too cool in cold weather, the B&M has a built in valve that only lets the real hot fluid to pass through, the cold fluid that is thicker gets back to the tranny faster to heat up

this is from B&M itself

........'stacked plate' design with multiple oil flow paths. The unit monitors resistance to flow by allowing a controlled amount of ATF to pass through a self-regulating orifice. Controlled by viscosity, thicker ATF is returned directly to lube through two bypass openings in the stacked plate core, while thinner ATF is directed through the core to cool as operating temperatures increase.


that said...I do not have a trans temp gauge and never did put in a scan gauge, left it in the taco

 

[meRockboost]

I know you said you already made up your mind to bypass, but here's a couple threads I started with some good discussion:

http://www.toyota-4runner.org/3rd-gen-t4rs/217667-trans-temps-bypassing-using-external-cooler.html

http://www.toyota-4runner.org/3rd-g...sion-temperatures-how-relates-life-fluid.html

The reason why I'm hammering you with info is because I believe many run to the bypass decision due to the fear of the pink milkshake and don't do enough research for the way they intend on using their rig.

Ok, I'll shut up now.

Agreed. I ended up running mine back to the radiator to keep up with temps while uphill crawling. And if you're that worried about pink milkshake $120 for a radiator is chump change compared to the other crap people are spending money on and NOT using (Icon stage 6 mall crawlers [5th gens *cough*])

 

[mtbtim]

I went with the 70264 and bypassed the radiator

while I did have concerns with it being too cool in cold weather, the B&M has a built in valve that only lets the real hot fluid to pass through, the cold fluid that is thicker gets back to the tranny faster to heat up

this is from B&M itself

........'stacked plate' design with multiple oil flow paths. The unit monitors resistance to flow by allowing a controlled amount of ATF to pass through a self-regulating orifice. Controlled by viscosity, thicker ATF is returned directly to lube through two bypass openings in the stacked plate core, while thinner ATF is directed through the core to cool as operating temperatures increase.


that said...I do not have a trans temp gauge and never did put in a scan gauge, left it in the taco

The bypass is a nice feature and I'm glad it's built into the cooler, because even with my in-series set-up, I could run too cool as well in very cold climates. But like I said, when you take the stock radiator cooler out of the equation, you are losing the ATF heating benefit it offers. So, with both of us running B&M 70264 coolers running side by side, my transmission temps will be higher due to fact I have the added benefit of the warming that happens inside the radiator. But, you have a 100% guarantee of never experiencing a pink milkshake and I still have a chance, even though I think it's a very sim chance.

 

[stivine6]

For those of you running these external coolers, how are you measuring the temps without a gauge? Does using a laser temp scan gauge work by measuring it directly off the B&M cooler?

 

[SpidermanGeek]

For those of you running these external coolers, how are you measuring the temps without a gauge? Does using a laser temp scan gauge work by measuring it directly off the B&M cooler?

Personally, I installed a gauge.

 

[the great him]

Yes, running two coolers will definitely help lower the temps, but at the same time, keep the trans fluid running too cool in colder weather. If it was just a case of running too hot, I'd probably have chosen to run a big cooler and bypassed the radiator cooler too. But like I've already stated, trans fluid has an optimum operating temperature range and running too cool will allow moisture to build inside the transmission which isn't good.

Think of it this way. Why do we have a thermostat for the engine? It's because without it, the engine would take longer to heat up to an optimum operating temperature. The thermostat keeps the coolant running through the engine until it reaches 180 degrees and then opens to cycle the coolant through the radiator to be cooled and returned to the engine. By the same token, the stock trans cooler in the radiator shortens the time it takes the trans fluid to reach optimum operating temperature because the cooler is bathed in the hot coolant and transfers heat to the trans fluid via conduction.

so youre saying dual coolers is gonna make it too cool? the FSM states that the transmission fluid can be checked at operating temps, operation temp is defined as the point where the transmission will shift into overdrive... that is roughly around 120*. if you think 120* is too cool feel free to stick your hand in 120* water on the stove and tell me its too cold (hint dont try that with oil). i run dual coolers and temps rarely climb above 180* normally, revently its been in the high 90s around here and ive been averaging closer to 180* +/- 10* in cold weather ie snow and freezing rain i only get down into the 150* range. i have never had a problem with the truck not shifting into overdrive. yes on cold mornings it takes a little longer, a couple miles, but by the time i hit the freeway im good. the main reason most of us here bypass the radiator all together is to prevent the pink milkshake -search for it. the only way you can completely eliminate this from happening is bypass the system. why do you think all new vehicles keep their trans coolers and radiators separate and no longer hose them in the same unit? also another thing to consider here is if you link the two together such as is done in stock set up, if one of the two components overheats it "infects" the other... if you are towing a heavy load and heat up the trans it will in turn heat the coolant and put more heat into the system than the radiator was designed to handle. same for the motor, if you start overheating the motor you can quickly overheat the transmission and burn up both. another thing to consider here is that the heat will compound on itself, and temps will rise exponentially faster the higher they go and the longer they stay there.

the system was designed around a stock vehicle with stock tires. bigger tires, aftermarket bumpers, sliders, roof top tents ect. means more work for the transmission and they simply where never designed to handle that kinda load. same goes with the cooling system, and since i have yet to find a larger aftermarket radiator that is not a one off custom made unit for under ~$900 keeping the radiator load as low as possible is also crucial.