Best tranny cooler to bypass stock radiator?
- Thread starter nacho
- Start date
BTO
Member
This issue has been debated here ad nausea. It was pretty much decided (at least in my opinion) that eliminating the risks of milkshake outweighed the questionable benefits of continuing to use the radiator. Maybe in really cold climates but not here in Cali. Our tranny is working flawlessly bypassed.
brian2sun
Elite Member
I agree with BTO. That would defeat the main purpose of doing the external cooler on a 3rd gen - to make sure the strawberry mlkshake doesn't happen. If you live in a cold environment, than the best option is to just get a new radiator every 7 years or so. That way you make sure the internal cooler doesn't get old and corroded enough to rupture and then you can forget the external one altogether since the stock one is still very efficient.
I have seen a few people get an external and keep the internal still hooked up. They weren't very happy when they ruined thier tranny a while later.
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Kurtis
New member
In theory you could throw a thermostat inline with the system. The average thermostat opens at 180 deg. And have someone machine a housing for it. I'm sure if you looked around you could find one that opens a little lower. Nominal operating temp is about 185 if I remember right.
Has anyone tried this? If not I will most likely try it in the next couple of months and do a detailed write-up on it.
Has anyone tried this? If not I will most likely try it in the next couple of months and do a detailed write-up on it.
maxspeed96ct
New member
From what Ive gathered , as long as the cooler is close to the radiator, and you allow the car to get to proper temp in cold weather I think it should be fine.
I live In connecticut so its something I thought about and looked into, I also might cover a good portion of the front of the oil cooler with some silver sheet metal tape to keep it warmer in the winter .
I plan on doing the 16 bottle flush when I install my cooler, damm its expensive but worth it.
I live In connecticut so its something I thought about and looked into, I also might cover a good portion of the front of the oil cooler with some silver sheet metal tape to keep it warmer in the winter .
I plan on doing the 16 bottle flush when I install my cooler, damm its expensive but worth it.
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BTO
Member
I don't know. No scangauge or tranny temp gauge. All I can say is it works flawlessly and the fluid looks and smells like brand new.
maxspeed96ct
New member
I hate to bump this thread again since it has been beat to death, But has anyone mounted or tried to mount inbetween the radiator and condensor coil?
Reason I ask is in new england winters I want to make sure the trans oil doesnt get too cold. Keeping it close to the radiator would keep it warm in the winter but still serve its purpose in the summer.
Reason I ask is in new england winters I want to make sure the trans oil doesnt get too cold. Keeping it close to the radiator would keep it warm in the winter but still serve its purpose in the summer.
quicksilvr
New member
Mine is mounted there. (between rad and condenser). It's fine in the winter, although the radiator isn't "keeping it warm" from a practical standpoint. Practical meaning: the radiator isn't helping it warm up. And once it's warm, it's warm...the heat from the ATF warms it way more than the heat transfer from the radiator.
However, it is not effecient enough in the summer. I'm going to switch to a larger cooler, and move it in front of the condenser.
nacho
New member
As far as anyone knows, has Toyota fixed this problem yet? I wonder if this radiator problem is specific to only certain years or if all of their vehicles with a 3.4L have this same problem.
Just a simple fitting that fails because it's made from the wrong metal is not acceptable....especially when it can cause so much damage to your tranny.
Toyota in general does a fantastic job of covering the details, especially with the rigs they still make in Japan like all the 4R's. Too bad they didn't catch this problem years ago and make it right :dammit:
Just a simple fitting that fails because it's made from the wrong metal is not acceptable....especially when it can cause so much damage to your tranny.
Toyota in general does a fantastic job of covering the details, especially with the rigs they still make in Japan like all the 4R's. Too bad they didn't catch this problem years ago and make it right :dammit:
brian2sun
Elite Member
I don't think they caught the problem years ago because it just takes high mileage and years to develop the issue. AFAIK, it's only 3rd gen 4runner radiators that have auto tranny and the 3.4. I've never heard of it on a Tacoma or anything else. It would be nice if Toyota did a free radiator replacement, but I'm not holding my breath. I guess they figure even with the issue, it's happening at about the same mileage as other brand's vehicles are grenading their entire engines so it's still not as bad as a KJeep or Chevy of any kind.
004Gunner
New member
You could do the configuration you suggested but it would keep the operating temp up by reducing cooling efficiency, not because the radiator would warm it up. It has obvious disadvantages during summer months and when towing though.
AddictedOffroad
New member
AddictedOffroad
New member
Big John and I both have 2000 4runners and Scan Gauge IIs. I run a large Hayden cooler and bypassed the radiator. John still runs the factory setup. We both run very similar temps this winter in pretty much all conditions.
FWIW, my tranny is up around 100*+ by the time I pull away from a couple stop lights. So is his. Even though his water temp is still below 100*. Mine is the same.
AddictedOffroad
New member
A thermostat in-line would block flow thus taking out your pump. That fluid is pumped through it from immediate start up. If you do it, you will blow a tranny line and likely take out the tranny within minutes.
The cooler he is referring to has an auxiliary fan that runs off of a thermal switch. When the tranny hits a certain temp, the fan will kick in to drop the temp. Once cool, it will shut off.
Mounting a setup like this up in front of the radiator is counter productive since it will also have air being pulled through it by the engine fan at all times. A setup like this is normally mounted inside the engine compartment.
maxspeed96ct
New member
do you guys cover the front of the cooler with anything in the winter ?
How long do you have let the truck warm up before the trans is at a safe operating temp.
AddictedOffroad
New member
Nope.
Letting the truck idle will only see marginal temp increase in the tranny and its only because its moving fluid. You need to drive it to warm it up. Your radiator will be ice cold until the truck reaches full operating temp anyway since the thermostat will not open until then. So, the theory that the radiator will warm the tranny up faster is an incorrect one.
FWIW, I have seen no decrease since installing my cooler except when I really need it when towing my pop-up around. AND, even then I am still in control of the temps by hitting the "OD OFF" button. When temps get above 200*, I simply hit that button and immediately temps will drop. The cooler isn't the final answer. Just a bandaid to help. You still need to be aware of where your temps are.
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maxspeed96ct
New member
Nope.
Letting the truck idle will only see marginal temp increase in the tranny and its only because its moving fluid. You need to drive it to warm it up. Your radiator will be ice cold until the truck reaches full operating temp anyway since the thermostat will not open until then. So, the theory that the radiator will warm the tranny up faster is an incorrect one.
FWIW, I have seen no decrease since installing my cooler except when I really need it when towing my pop-up around. AND, even then I am still in control of the temps by hitting the "OD OFF" button. When temps get above 200*, I simply hit that button and immediately temps will drop. The cooler isn't the final answer. Just a bandaid to help. You still need to be aware of where your temps are.
K good to hear, I always let my car sit and idle for a few minutes always before pulling away. Just habit.
My reason for installing the cooler is more for maintance purposes and to avoid the awfull coolant/atf fluid mix . I dont do much towing.
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