FogRunner

Recently I helped a fellow 4runner owner install a aftermarket transmission cooler on his 2002 runner. In the process I discovered how critical the mounting location and position are.

He wanted to avoid the milkshake risk to his transmission so he asked me to help install a transmission cooler. We used the same cooler and aftermarket filter assembly as mine and for all intents and purposes it was identical except for the location of the cooler.

Instead of attaching his cooler to the condenser like I did on mine with plastic zip ties (which work really good IMHO) we bolted his to the center and side supports as most here on Yota tech have done. This mounting solution resulted in about a 2 inch gap between the cooler and the condenser core.

Well after the install we went out to the beach and started wheeling in the sand. After about 10-15 minutes we stopped and he asked me what kinda temps I was seeing on my transmission. I told him nothing more than 185F and he was shocked because he was seeing it hovering between 220-230F.

Since both systems were identical we realized the mounting situation was the only variable between the two. So in an attempt to see what the airflow was doing we used a cheap fog machine about 2 feet in front of the transmission cooler and reved up the engine.

The results were very surprising and told use exactly why the cooling was so much less with his mounting system. As the fog got close to the cooler it took the path of least resistance and went around the top and bottom of the cooler meaning there was very little air flow going though the cooler.

We then did the same test on my 4runner with the cooler mounted on top of the condenser and the airflow results where night and day. Even at idle you could see how the engine fan was pulling plenty of smoke/air though the transmission cooler.

We unbolted his cooler and attached it to the condenser like mine and did some more wheeling in the sand and his transmission temps dropped big time and like me he never saw over 185F.

So whats the verdict?

If you use your 4runner for towing and mostly highway driving mounting away from the condenser is OK because the air will be forced through the cooler by the vehicles speed.

However if your going to be wheeling or in stop and go traffic where the transmission cooler is depending on the engine fan for air flow then mounting the cooler directly to the condenser is the only option.


FOG

mt_goat

Fog machine? Good idea FOG

I might just add, I saw very good results with a cooler mounted between the AC condensor and radiator. But its a harder install (must remove the radiator) and you must use a thin cooler.

Ritzy4Runner

iTrader: (1)

Glad to see some one did some data collection but there is still more then one way to mount and cool. If you are not using the clutch fan (a.k.a. Taurus/electric fan mod) then even in the location you described will not change as the fan is regulated by engine coolant temperature and not a function of the engine clutch fan.

It is true you need adequate air flow across and through the coils in order for the system to cool correctly and keep your temperature low. As has been shown in other installs, the cooler was mounted in the space behind the skidplate on one 4runner with an attached fan to pull air through it and was very effective. If you are going to do any serious wheeling in warmer areas of the country as well as steep grades and gear changes you will need more then your clutch fan as well.

It will all depend on your application. I am still trying to locate and install temp gauges in my system to monitor the temperatures in my system before and after I perform my cooler install. As I mentioned, I can't mount it directly against the other coils as there isn't enought room to do so and would tend to block natural air flow to my radiator in normal driving. This would result in driving up my engine temp. sort starts to defeat the whole reason for isntalling the cooler. One way or the other I hope to add more information to this onging issue.

MT, going to check out the local hardware store to find the biggest fittings for installing in my hose lines

ScottyC

iTrader: (1)

I just installed a Hayden 405 yesterday and bypassed the stock cooler as well.

It is very critical to get the new cooler against the A/C condensor. I see zero difference whether its between the radiator and condensor or just mounted to the outside of the condensor, but its critical to get it flush against one. Otherwise the fan will not pull air through the cooler. It will only cool at highway speeds.



The cooler was $43. Its designed for 20,500lb rated vehicles such as motorhomes and stuff.

I will be running a supercharger on a 2wd tranny in my new crawler, so its very important to me to keep it cool.

FogRunner

Rizty don't take this the wrong way but your not making much sense.

Plenty of car manufactures put the condenser/transmission cooler and even a inter-cooler if its a turbo charge vehicle inline with the radiator and have no air flow issues.

I have my transmission cooler attached to the condenser and in 95F+ weather my engine temp is rock steady be it off roading in the mud or sand, pulling a 5K boat through stop and go traffic or on the highway.

The engine fan has plenty of power to deal with the resistance a small foot print 1.5" transmission cooler offers. When I did the smoke test with the cooler on my 4runner I saw no difference in the volume or velocity of the air being pulled through the cooler vs the rest of the condenser. Also in "normal driving" the air pressure is more than enough to push through the trans cooler, condenser and radiator. As I said above plenty of vehicles have several heat exchangers in front of the radiator with zero problems.

And as far as a Taurus fan issue, all you need to do is put a thermal switch in the transmission cooler circuit to make the fan switch to high speed when the fluid gets above 180F.

Why don't you have enough room? I've helped several friends with 3rd gen 4runners mount the same cooler I have to their condenser core with zero fit issues.

Sure guys mount them down in the skid plate of 2nd gens and under the belly of 3rd gens with a fan attached. There is no argument a remote mount trans cooler with a fan is effective. The only issue is with having it mounted down low or under your vehicle you have to deal with mud and road debris with gets into the issue of reliability.



FOG

J2F42C

Great post Fog. It could not have been said better. Everyone who installs an aftermarket cooler should be made to read this. Like in real estate, location...location...location....

Having a Scangauge ii at my disposal, with my 70264 cooler on the condenser, I can actually watch the ATF temperature drop 2-8 degrees within 60 seconds after I come to a stop in traffic. I would think that such is mostly and/or solely attributable to the fan CFMs cooling down the B&M. Such is the reason Fog argued for everyone to replace their fan clutch at the first hint of failure in another post....

brian2sun

That's some good science there, thanks for letting us know that. I'm getting ready to do mine one of these days soon and I'll definitely be mounting it to the condenser now. The e-fan obviously wouldn't hurt, but I'm wondering if it may be overkill. I only say that because as you know, the problem with the stock one isn't that it's inefficient, it's just that it ruptures and mixes fluids. AFAIK, the cooling ability of the stock unit is actually pretty good. Since it's only cooled with wind and the engine fan (or more precisely, it's cooled by the coolant that's cooled by wind and the engine fan), wouldn't Fog's way be just as effecient (or even better since it's exposed to even more wind)? Just wondering..

Fog, would you mind taking some shots of yours mounted up (or link to a previos thread)? I'm not too worried about right now since my radiator is only about 5 yrs old, but I know it's one of those things that if I don't get on it soon, the strawberry fairy might pay me a visit.

pendrag

Installation of my B&M 70264 in my 1999 4runner:

Photos of the cooler mounting with commentary

Photos of the mounting and the hose connections

Ron Helmuth

really good thread guys and I am glad to see this becoming more scientific in discussion and less "this is what I think will work best".

We did my friend's 01 Limited Runner (auto tranny of course) radiator on Sunday the 27th, and for the average non off roader or towing owner- I do feel a radiator replacement every 7-9 years is a better option and easier to do than ever messing with an external cooler.

But I know if I had an auto tranny I would be doing this on my own rig. Glad to see the science behind everyone's point of view.

chris360hawks

Pics would be great fog! That way it will clear up any questions as to where exactly it is mounted.

96743runner

Ahhh thanks for posting this up Fog!! Your info will definitely will help me when I redo my install and upgrade from a 4454 to a B&M 70274

gdutch

Thanks for that info Fog, I'm glad somebody finally took a scientific approach to it. My own install was kind of a hybrid, I used the mounting brackets that came with my TruCool, but bent them down so they would hold it flush against the AC compressor, and added a single zip tie for good measure.

tunnelmotor99

I mounted my Tru-cool to the condenser using the special zip ties. I made sure to mount it directly in front of the fan, and according to my trans temp gauge the fluid never goes above 150 when idling in traffic and stays at about 120 while driving.

Hockeyrunner

I really like the specs on the 405. I live in CA so I don't see a need to have a external bypass cooler as I don't think the 405 has one. Im gonna switch out my 4454 tru cool for either the 405 or b&m 70264.

How do you use the zip ties through the cooler? Probably a stupid question but do you just push them through & the click & hold?

Hockeyrunner

My tru cool might be cooling efficiently, who knows. I dont have a gauge & don't have $170 right now for a SGII

J2F42C

I would imagine right now Fog is keeping his eye on Alex so I'll attach the link for pics of his cooler that I bookmarked back in April...

https://www.yotatech.com/forums/f2/m...53/index2.html

FogRunner

Yes and this may sound like common sense but don't put the zip ties through the condenser AND the radiator. You would be surprised how many people I've seen that just slap the cooler on the front and run the zip ties in till the stick out the back of the radiator and then put the back clips on them. What happens when you do this is it bows the condenser and radiator towards each other and causes leaks.

When you go to install it all you need to do is drain a little bit out of the radiator and take off the top hose and 4 mounting bolts so you can lean the top back enough to get your hand between the two and put the backing clips on the zip ties.

Yea J2 I'm keeping my eye on Alex but luckily all I'm seeing is 4feet about average high tide which is enough to come over my bulkhead and a little bit into my yard. Mostly been busy with taking upper level college physics in a summer semester, yup nothing like changing careers in your 30s.

FOG

Rock Slide

iTrader: (1)

While we're on the subject of stupid questions, one just hit me. What pushes the fluid from the tranny to the external cooler? Looking at Scotty's external cooler pic above in post#14, the inlet hose looks like it's at a 75 deg angle.

Obviously in a stock setup where the fluid travels from the tranny, to the bottom of the radiator and then back to the tranny, the fluid basically travels across a horizontal plane. But with an external cooler, the fluid has to almost climb a hill to reach the cooler and then rapidly decend upon exiting the cooler.

Just wondering what pushes the fluid from the tranny to the cooler and does it cause more undue stress having to push the ATF up vertically to a cooler rather than horizontally to the stock radiator?

frodin1

I've got a Hayden 679 and I'm Living in Havasu where it's currently 115. I've had it mounted with the zip ties for about 5 years and haven't had any issues with it breaking off. I do check once in a while however, plastic/nylon or whatever does not last very long out here at these temps! Just in case anyone was questioning the zip tie method, it works fine!

tunnelmotor99

No such thing as a stupid question. There is a fluid pump in the front of the trans that is turned by the torque converter, which is turned by the engine. So as long as the engine is running, fluid is being pumped through the lines. The pump is the heart of the automatic trans since fluid pressure is what applies and holds the clutches.