Transmission Cooler
 

I know that this write up has been done before, but I had some unanswered questions when I went to do mine, so here is my write up:

The parts I used:
B&M cooler #70268 from Summit Racing
2- 3/8” to 3/8” hose barb connectors (home depot)
2 additional hose clamps for a 3/8” ID hose
1 quart of Mopar ATF-4 Transmission fluid

1. Remove the front grill. Use a Philips screwdriver to remove the 6 plastic retaining screws (for on 07 – for an 08, you will just pop them off with a flat head). I used a flat head to pop the retainers out after that.

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2007 Grill Screw

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2008 Grill Clip

The grill will just pop off – don’t forget to unplug the parking lights.

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2. Unpack your cooler.

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The mounting orientation of the cooler is VERY important. I called B&M on this, because I was not sure. The least efficient way to cool is by having the hose outlets facing down. The MOST efficient is to have the cooler mounted with the outlets up or on the side. If you choose on the side, make sure the INLET (from the factory cooler) is on the bottom and the top hose goes to the transmission. This is VERY important.

I did not feel comfortable pushing the plastic zip tie things through my condenser and radiator, so I mounted my cooler with the supplied brackets. This also puts the cooler a couple inches away from the condenser for better cooling. I cut the brackets to length with a Dremel and used the supplied hardware to bolt it in. I had to drill holes in the lower grill brace to bolt the lower cooler brackets to. You could paint your brackets black (which would look nice) – I did not.

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3. Route the first hose from the bottom of the cooler under the Jeep and to the upper transmission hose. Make a cut here. Use the remaining hose, and run it from the top of the cooler, route it the same way to the same location. Note which hose is which. At this point, attach a 3/8” hose to 3/8” hose barb adapter to the end of each hose and secure with a clamp.

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4. Next, I put the font of the Jeep back together (remember to plug the lights back in!).

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5. Place a drain pan under the transmission hoses. Get 2 hose clams ready, use some cutters, and cut the UPPER transmission line in the center of the rubber section. I worked from the top (under the hood). Slide a hose clamp on each side of the transmission line and slide the hoses with the hose barbs into the transmission lines. The one from the bottom of the cooler will go to the hose coming from the front of the Jeep. The one from the top of the cooler will go to the hose going towards the transmission. Secure the clamps. Wipe up the little transmission fluid that dripped.

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Crawl under the Jeep, check the hoses to be sure they are not hanging. If so, secure them. Take it for a drive and get it good and warm. Check the fluid. I had to add about half a quart.

This dropped my temp from ~220 to ~170 (on the Unlimited with 4.10's)

The temp sensor is in the metal line closer to the transmission.

Do you think this would help keep the steam from a cold rain or a puddle from spewing out from under the hood?

:thinking::thinking:

x2 :dontknow:

I am guessing the same. The steam the blows from the grill is off the trans cooler not the radiator. If the radiator is getting so hot the in a cold rain it is boiling off the rain water - oof! So with the added trans cooler the crazy looking clouds of steam should go away. I would guess that at this point.

On a side note - I called my dealer today and Jeep does offer an aux. trans cooler - for $318! I am going to try and get a part number and picture next time I'm at the dealer. Anyone know of this or have more info... may be worth it if it make it more warranty happy. I do have lifetime on mine.

Haha :oops:

Where do you measure the transmission temp, and how did you measure it for your comparison?

I installed a temp gauge before I did the install and watched it for about a week and a half. It's inline on the return line from the cooler, just before it reaches the transmission. My transmission would typically run 190-200 without the B&M cooler...it peaked at over 220 (this is with NO trailer). After this install I have yet to go over 170. I will be pulling my trailer this week sometime...I am intersted to see how it performs. :)

Oh, when I am on the highway and the TC locks, it runs at about 135-140...instead of 170-180... :thumbs:

You sure about that? Does it all the time on mine which is a manual tran. No trans cooler.