Radiator choice w/ tranny cooler install

[Drcoffee]

I keep reading posts here where members are encouraging people to just by-pass the radiator transmission fluid cooler to avoid the strawberry milkshake problem. First, just spend the $120 to buy a new radiator. Koyo rads are on ebay all day long. That will give you some peace of mind. Now also add the extra B&M aux cooler, but do not just bypass the radiator. The radiator cooler serves two functions. It warms the trans fluid to operating temp quicker than the transmission can do on its own, which help prolong its life. Second, it cools the transmission better than just an air-cooled aux cooler can do. A liquid to liquid cooler is far more efficient than an air to liquid cooler. If you overheat the transmission, it will die quickly. Why then add a cooler to the transmission line?? Because the optimal temperature for a transmission is around 160-180 degrees. The radiator is typically at 180 degrees. So by adding the cooler inline "after" the radiator, you bring the temp up quickly using the engine coolant, but then keep it down below 160 degrees by cooling it again through a 2nd cooler. The B&M cooler should be able to ower the oil temp by 20 degrees +/-. I've been able to monitor this effect on other cars I've had with a diagnostic interface and always had to restore the radiator cooler because the transmission temps would soar above 220 degrees with just an aux cooler alone.

I pulled this from an AMSoil site. Look at the conventional oil graph.

 

[tbst]

Going through and posting the same paragraph on several threads isn't useful.

It has been proven that using only the after market cooler will be fine. It's not up for discussion. Even Alex Jones wouldn't waste his time not believing in it.

 

[Drcoffee]

Going through and posting the same paragraph on several threads isn't useful.

Really?? I disagree. Not everyone will read this thread who should be aware of the radiator delete modification. If you decide I'm full of dung, just ignore this post but most people here are wrenching for the first time on their new/used 4Runner. A contrary view can be helpful to make a solid choice.

Honestly, I'm really suprised by the agnst I've caused with this topic. Its almost like I've wronged somebody. Please do what you want but don't stroke me because I'm not drinking the cool-Aid.

 

[tbst]

You aren't presenting it as a contrary view, you are presenting it using hysteria. "...temps will soar above 220 with a cooler alone", this is not a fact or even close to it.

Why have so many people here had such success running a tranny cooler only if it such a problem?

 

[Drcoffee]

You aren't presenting it as a contrary view, you are presenting it using hysteria. "...temps will soar above 220 with a cooler alone", this is not a fact or even close to it.

Why have so many people here had such success running a tranny cooler only if it such a problem?

I don't know how to respond to your assumptions. The fact is, the B&M like any cooler has only the capcity to lower a fluids temps by so much. In the case of these B&M coolers we're using, its right around 20 degrees. Also, be mindfull that the oil in the pan is going to be cooler than the oil exiting the transmission. So the operating temp will be higher than where most folks install their temp gauge which is typically in the pan where circulation can be limited. Do a little research and find out how efficient these little coolers are. Just like air conditioning, it can only change the temp so many degrees from the air passing over it. If you have outside air that's 100 degrees, the best you'll get inside the car is 80. That's why they have MAX cool which recirculates cool air from inside the car because only then can you get temps down to 65 degrees while its 100 outside.

So if your trans fluid gets to 220 degrees, the B&M will only get you back to 200. Its not a magic radiator. It will only remove so much heat and if the temps keep rising, its helping but not much.

The panic and hysteria is what's being fostered here about a broken radiator. OMG everyone, remove your radiator completely or your truck will implode!

Just buy another brand that doesn't suck like the factory Rad and you'll be fine. The problem here is that a few individuals believe that as an EMT or office worker or name your job, you are so much smarter than the ENGINEERS at Toyota. Somehow I take issue with that. Call me nuts.

 

[Qyota]

The AMSoil graphic you posted refutes your own argument that a transmission needs to be between 160-180 degrees to operate properly.

 

[Drcoffee]

The AMSoil graphic you posted refutes your own argument that a transmission needs to be between 160-180 degrees to operate properly.

How so?? You never want to operate machinery right at the very edge of its design specs.

If you look at the chart, the optimal max temp for petroleum fluid is is below 170 degrees. You have petroleum trans fluid in your transmission, so you would do well to stay below 180. I don't see the contradiction here. The chart is showing you the transmission fluid operational range. If the fluid gets too hot it breaks down and so will your transmission. I defer to the Toyota engineers on this subject. They designed the fluid to be cooled by the radiator and I'm going with that.

But hey, you are probably smarter than all of them combined. I bow to you sir.

I'm done here. I've stated my case the best I can and now you decide what's best for your 4Runner.

 

[T4R_Finally]

Coffee, I for one, appreciate your point of view and have no problem with you posting in multiple threads. At least it is information someone can use to make their own decision. And not everyone will read every thread or find every thread when searching later on. It's no different than people responding to every one of these threads and saying "install a bypass tranny cooler!".

Your point about the Toyota engineers is a good one. These vehicles are now legendary for their longevity. External tranny coolers didn't get them to hundreds of thousands of miles - their original design and drivetrain, based on the engineering did. It's not just 4runners, Toyotas as a whole have a long standing history now for making vehicles that last longer than other makes. If my original design got my 4runner from 2000 to 2012 in the condition it is in now, why do I need to suddenly add components to it when I'm not changing the driving application? Just keeping the original design by replacing components before they fail should be sufficient. If one wants to add an external cooler, then fine, but that's not the magical secret to keeping these things running. If I were to run an external cooler, at all, it would be in line with the original type radiator/cooler - but that's just my decision based on information, like yours, that I've read. These forums and threads typically do not provide a definitive answer to every question or issue. It is a source of information to use for research to make one's own decision in the end.

 

[tbst]

My point is that affirmatively writing that you are going to trash your tranny if you install a by-pass cooler is unnecessary hysteria. And misleading, especially being that Drcoffee hasn't even done that on a 4runner...

One thing is for sure, if you have an older radiator, don't have $70 extra bucks, and think you are ready to trash your transmission with a pink milkshake, installing a by-pass cooler will stop it from happening. As will installing both a new radiator and a by-pass.

 

[Qyota]

How so?? You never want to operate machinery right at the very edge of its design specs.

If you look at the chart, the optimal max temp for petroleum fluid is is below 170 degrees. You have petroleum trans fluid in your transmission, so you would do well to stay below 180. I don't see the contradiction here. The chart is showing you the transmission fluid operational range. If the fluid gets too hot it breaks down and so will your transmission. I defer to the Toyota engineers on this subject. They designed the fluid to be cooled by the radiator and I'm going with that.

But hey, you are probably smarter than all of them combined. I bow to you sir.

.

That's funny. It's just a conversation, no need to get huffy.

I have no issues with the engineering of the system. You're reaching here.

My point about your graphic is that your lauded Toyota engineers have specified Dexron III for this application. By your logic, we should ONLY use that fluid, and that since Toyota specifies it, it's the best. That rules out AMSoil synthetic. Oh, and you don't think AMSoil created that graphic to sell more of their product? Come on.

 

[Qyota]

And what's more, with an OBD-II tool one can monitor the trans fluid temperature at the output. Some of us have done some testing in this regard, and temps with the bypass are not necessarily (as you argue) any higher than with the stock system.

I'm still waiting to hear why 160-180 is the ideal trans fluid temp.