Auxilliary Transmission cooler

[Robinhood4x4]

Although the bottom of the radiator acts as a tranny cooler, my A/T light has come on exactly 3 times in the past 10 years. The first was while coming back from Arizona, carrying a full truck load of people and gear while doing 70mph in 100 degF heat. The second time was while bombing around Pismo Dunes at 30-40mph in the soft sand. The third time was while going up an incredibley steep grade for about 1 mile while completely loaded down with people and gear. I figured all that heat probably wasn't doing the tranny any good so I added an auxiliary tranny cooler.

There are 2 types of coolers out there, the "tube and fin" style and the "plate" style. From my research on the internet I found that the plate style is the most efficient. If one is an electrician or an EE, a good analogy for the two types is the tube and fin is series and the plate style is parallel (not to be confused with how one installs the cooler in relation to the radiator).

The TRD cooler is a stacked plate style and costs a small fortune. I opted for a Hayden plate style cooler from the local auto parts store for $50. The quality is just as good as the TRD and costs a ton less. I got the smallest one they had because at the time I didn't know where I was going to mount it. It's a good thing I did though, because it fit perfectly.

Installation was pretty straight forward. Normally, the tranny cooler is mounted either in front of the radiator or behind it, but I couldn't see anywhere it would fit and I was too lazy to take off the bumper. So I got some 1/8"x1" flat bar, drilled some holes and bolted it to the tranny cooler. See below for a picture of this mount.



Then, I dropped the skidplate and bolted the tranny cooler up to some existing holes in the front cross member. Plumbing the cooler was really easy. I took off the line where the fluid exits the radiator and connected the new line. This new line was then routed to the tranny cooler, trying to keep the line as straight as possible, and cut. Another new line was connected to the other side of the tranny cooler and routed to the tranny inlet hard line. Very little tranny fluid came out during the whole process. Previously, I had done a tranny flush and so I remembered which line was the inlet and which was the outlet. Unfortunately, now that I write this I forgot which is which.

To increase the air flow to the tranny cooler I drilled (2) 2inch holes in the stock skidplate. The skidplate bolted right back up without interference from the cooler. I got a chance to test it out on that same steep grade and it passed with flying colors, no tranny light.

Keep in mind that because of the location of the cooler it can be vulnerable to impacts or other damage. If the cooler were to break open and loose all the fluid, you'd likely need a new transmission. But so far I don't have any dents that high in the skid plate.

Update: I did finally get the tranny light to come back on but it was under extreme conditions. I was driving in soft gravel in 4hi going fairly slow, about 15-20mph so very little air was flowing through the cooler.

Here's a couple more pictures:





Update 3-20-07
Since doing a solid axle swap, I moved the tranny cooler up higher and out of harms way.

[slosurfer]

I like your new location, much more protected and much better airflow. As another option here is how I mounted mine.
I mounted a transmission cooler that I ordered from Import Performance Transmission. After searching and looking all around the front end of the runner for a place to put it, I finally got it mounted behind the grill. It took a long time for me to get it just right. I had to trim the backside of the grill to make it fit and let me tell you I got real good at taking that off. It was just cut and fit, cut and fit. The brackets that came with the cooler were much stronger than they looked, it took some muscle to bend them and shape them how I wanted them to. I am real happy with it so far, I will probably trim the grill a little more when I get the right attachment for the dremel, but it clears everything right now. Anyways, here are the pics:













Let me know what you think or if I missed anything. The lower right mount is mounted to the bumper using a bolt that holds the valance on. I really couldn't get a pic of it.
One tip that would have helped me, once you remove the grill, remove all the little clips that way you don't have to mess with them while you are cutting and fitting. This would have saved me a lot of time, unfortunately I didn't think of it till I was done. The model of cooler I got was the True-Cool LPD4454 which is 7 1/4" x 11", I forget what it is rated for but it is big and the hardware that comes with it is awsome. I got it from ipttrans.com

[Robinhood4x4]

Folks, Chris is the pioneer of tranny cooler placement. He was the first to successfully get that tranny cooler behind the grill and document it for us to see.

[slosurfer]

Thanks, Steve. I used your writeup as a guide, I was just pretty determined to make it fit. I was just about to give up and put it behind the valance, when I realized that we have no problems trimming stuff to make other stuff fit (i.e. tires, bj spacers, etc...) why not trim the backside of the grille. Luckily by then, I was savvy enough to take pics, I'm still pissed that I left the clips in to do all my cut and fit. I am lucky I didn't break any. I think I spent the majority of the time messing with those dang clips.

So far this cooler has worked just like it should. I have been on all day 4lo trails with the air temp hovering around 100 degrees and my tranny temp is at 130 degrees (my sender is before any of the coolers, so I am reading the hottest temp that my fluid is reaching). Recent trip to DV, very hot, AC going, deep soft gravel, lots of grades, and trying to keep up with a V8 4runner, my temps were hotter but nothing scary and it held up great to all the jarring and vibrations on the washboard roads.

Another option are the coolers that have the built in fan, I haven't heard how good these work, but I would think that Steve's location behind the skid plate would be the perfect place for one.

[military_stang]

Although the bottom of the radiator acts as a tranny cooler, my A/T light has come on exactly 3 times in the past 10 years. The first was while coming back from Arizona, carrying a full truck load of people and gear while doing 70mph in 100 degF heat. The second time was while bombing around Pismo Dunes at 30-40mph in the soft sand. The third time was while going up an incredibley steep grade for about 1 mile while completely loaded down with people and gear. I figured all that heat probably wasn't doing the tranny any good so I added an auxiliary tranny cooler.

There are 2 types of coolers out there, the "tube and fin" style and the "plate" style. From my research on the internet I found that the plate style is the most efficient. If one is an electrician or an EE, a good analogy for the two types is the tube and fin is series and the plate style is parallel (not to be confused with how one installs the cooler in relation to the radiator).

The TRD cooler is a stacked plate style and costs a small fortune. I opted for a Hayden plate style cooler from the local auto parts store for $50. The quality is just as good as the TRD and costs a ton less. I got the smallest one they had because at the time I didn't know where I was going to mount it. It's a good thing I did though, because it fit perfectly.

Installation was pretty straight forward. Normally, the tranny cooler is mounted either in front of the radiator or behind it, but I couldn't see anywhere it would fit and I was too lazy to take off the bumper. So I got some 1/8"x1" flat bar, drilled some holes and bolted it to the tranny cooler. See below for a picture of this mount.



Then, I dropped the skidplate and bolted the tranny cooler up to some existing holes in the front cross member. Plumbing the cooler was really easy. I took off the line where the fluid exits the radiator and connected the new line. This new line was then routed to the tranny cooler, trying to keep the line as straight as possible, and cut. Another new line was connected to the other side of the tranny cooler and routed to the tranny inlet hard line. Very little tranny fluid came out during the whole process. Previously, I had done a tranny flush and so I remembered which line was the inlet and which was the outlet. Unfortunately, now that I write this I forgot which is which.

To increase the air flow to the tranny cooler I drilled (2) 2inch holes in the stock skidplate. The skidplate bolted right back up without interference from the cooler. I got a chance to test it out on that same steep grade and it passed with flying colors, no tranny light.

Keep in mind that because of the location of the cooler it can be vulnerable to impacts or other damage. If the cooler were to break open and loose all the fluid, you'd likely need a new transmission. But so far I don't have any dents that high in the skid plate.

Update: I did finally get the tranny light to come back on but it was under extreme conditions. I was driving in soft gravel in 4hi going fairly slow, about 15-20mph so very little air was flowing through the cooler.

Here's a couple more pictures:





Update 3-20-07
Since doing a solid axle swap, I moved the tranny cooler up higher and out of harms way.

How come you would mount it there... it doesn't seem to be the best place in the world, making is suseptible to rocks and bashings....????

military_stang

[Robinhood4x4]

If you mean down below behind the skid plate, I wheeled like that for several years and never had a single dent in the upper area of the skid plate where the cooler was. I wasn't doing rubicon level trails, but one step below.

[military_stang]

Really, i would have imagined that thing getting smashed... sweet, i like it

military_stang
:respect:

[Marc P]

I have moved mine 3 times now...I think it is good now..

[ChickenLover]

I decided to go with a B&M Cooler. I picked this one up at summit for about 50 bucks. 5.75" X 11" X .75". It came with 5ft of hose and a whole bag full of hardware. Most of which, I didn't need. I ended up needing an additional 5 ft of hose, which I found at Napa. If you are setting up a cooler, make sure you use transmission fluid hose. Not heater hose.

After seeing Slosurfer's set-up, I decided to mount it right behind the grill. As you can see, it will get maximum air flow.











Instead of mounting it on its side, I chose to mount it with the barbs facing down. It just seemed to fit easier this way. I drilled an additional hole between the two existing holes (on the cooler) and used a pre-existing bolt to tighten 'er down.






On the top, I used the mounting brackets included in the kit. I used tin snips to make room for the grill.






Here you can see where I did a very mild grind on the grill to make room.






Top view: There is about 1/4" of clearance between the grill and the cooler.







Done.. You can barely see it back there.

[slosurfer]

NIce. I didn't even think of notching the cooler, good work. Next time I have my grill off, I may just see if I can do that with mine. Believe me, I tried to get it to fit there, I even tried to fit it between the ac fan and the condenser. Mine is slightly wider, 7" so I will have to see if notching the cooler will help mine to fit like that. As it is almost half of it is behind the bumper, but I already knew that I wanted to get a tube bumper, so eventually it will see more air. How much of a pain was it to get that grill off with your brushgaurd there?