I have a 4.3tbi Chevy with a TH350 and the temps are getting way too hot. Right now I have a small B&M cooler in front of the radiator (which has an electric fan), but when driving uphill for awhile the temps still get around 220 degrees and sometimes even hotter. I have a Perma-Cool remote tranny cooler with fan that I would like to install, but I was wondering if I could still keep my old cooler and run both? My plan is to run the return line from the B&M to the remote cooler that I plan on mounting under the truck near the t-case (the only spot I can find to mount it). I'm just worried that the transmission fluid lines will be too long. Should I just get rid of the B&M and mount the remote cooler in front of the radiator? Thanks!

Install it and forget it. It's common to use an external cooler along with the in-radiator cooler most auto rigs have. What you want to do is essentially the same thing.

The tranny doesn't know how long the lines are. If you use steel or aluminum tubing, you have that much more opportunity for cooling capacity.

I am gonna ask a possibly insulting question here..... When you ran the B&M you didn't disconnect the lines from the radiator did you? If you did, put em back. The B&M, like the Permacool or any other trans cooler is an auxliary "in addition to" cooler. You can't cool tranny fluid with air. At least not at first. You have to run it through the radiator loop, cooling it down to the water temp, then through the aux cooler to bring it down further. I have seen this done more than once before. If you havent done this....my apoligies:emb2: In that case, I would just replace the B&M with the Permacool. I am assuming the B&M doesn't have a fan. Because they do make some nice fan ones that use a plate system that is better than the Permacool round tube models.

Dont connect it to the radiator. All that does is heat your tranny fluid to engine temp ~180-200*
I did this with my YJ and had a large external cooler. Temps were ok but never where i wanted them. Disconnected them from radiator and tranny temps wnet down 10-15* at least.


I would look to see why your tranny is running that hot. What is your gearing, tire size, ratios????

Agreed. Skip the radiator. Mine was actually heating the tranny fluid.

You can use an A/C Condensor... It holds alot of fluid but works very well...

On top of that you could run synthetic ATF which would help lower temps also.

First off, thanks for all the replies. About my rig: It's an '85 4Runner with an aluminum radiator (so no radiator trans cooler) and all its got is the B&M trans cooler right now. It has 4.56 gears and 38.5x14.5 Swamper SX's. Right now I'm running semi-synthetic ATF. So I can essentially keep the B&M and run the return lines from that to the remote cooler located under the truck? The only thing I'm worried about is that the lines are too long for the tranny to pump fluid through it.

I have done many swaps using scat VW remote oil cooler setup as a stand alone unit, with electric fan and adjustable thermostat unit from imperial (checker auto) the whole setup costs about 160.00 and works with any tranny. I usually mount on the inner fender of the engine compartment

I will take and post up some pics later today.........the auto pump is plenty strong to pump fluid to anywhere on the rig.......we did a test once with a 1/2" line on a turbo 350 pointed skyward and extended 5" above tranny...it shot out about another foot above....no worries:flipoff2:

I have done many swaps using scat VW remote oil cooler setup as a stand alone unit, with electric fan and adjustable thermostat unit from imperial (checker auto) the whole setup costs about 160.00 and works with any tranny. I usually mount on the inner fender of the engine compartment

I will take and post up some pics later today.........the auto pump is plenty strong to pump fluid to anywhere on the rig.......we did a test once with a 1/2" line on a turbo 350 pointed skyward and extended 5" above tranny...it shot out about another foot above....no worries:flipoff2:

Unfortunately I don't have any room in the engine compartment, and no inner fenders either. The only spot I could find underneath the truck is on the passenger side between the t-cases and the frame rails. It's protected very well up there, I'm only worried about the extra heat from the t-cases. Hopefully with your test you mean extended 5 feet above the tranny and not 5 inches. :flipoff2: Anyway, the fluid line is going to be about 3' from the tranny to the B&M up front, then about 6' back to the remote cooler, and then 3' forward back to the transmission. That would be a total length of 12' give or take a foot or two. Do you still think it can handle that? Thanks.

Unfortunately I don't have any room in the engine compartment, and no inner fenders either. The only spot I could find underneath the truck is on the passenger side between the t-cases and the frame rails. It's protected very well up there, I'm only worried about the extra heat from the t-cases. Hopefully with your test you mean extended 5 feet above the tranny and not 5 inches. :flipoff2: Anyway, the fluid line is going to be about 3' from the tranny to the B&M up front, then about 6' back to the remote cooler, and then 3' forward back to the transmission. That would be a total length of 12' give or take a foot or two. Do you still think it can handle that? Thanks.

NP at all, most trucks have atleast that amount stock. my XJ has about 14' and the MJ about 15' you are telling me you dont have 10" x12" x3" spot under the hood anywhere?

http://www.fototime.com/%7BB362DC33-DCA9-4530-8A92-283BC526AA5A%7D/picture.JPG

NP at all, most trucks have atleast that amount stock. my XJ has about 14' and the MJ about 15' you are telling me you dont have 10" x12" x3" spot under the hood anywhere?

http://www.fototime.com/%7BB362DC33-DCA9-4530-8A92-283BC526AA5A%7D/picture.JPG

Well the dual batteries take up a lot of space. I might be able to find a spot somewhere, but I figured it would stay colder underneath the truck rather than in the engine bay. So what do you think is the maximum amount of line I should run? Thanks for the help!

stock is usually 3/8" line that is what I use. under the truck is ok if you never flip stuff up into it........I kinda like it protected

stock is usually 3/8" line that is what I use. under the truck is ok if you never flip stuff up into it........I kinda like it protected

Yea I'm using 3/8" also. I was actually referring to the maximum length of line I should run without problems pumping fluid through it. Thanks.

Yea I'm using 3/8" also. I was actually referring to the maximum length of line I should run without problems pumping fluid through it. Thanks.

probably 45' or so...........it is rise in the lines that is more important in length.........

you might also want to check ebay, they have decent prices on tranny coolers, I found a couple on there that were like 30" long and finned, just my .02

It is my understanding you can "overcool" your tranny and you want the tranny fluid around 180. This allows all moisture to be "cooked" out. Running it through the radiator allows it to maintain a minimum temperature that will eliminate the over-cooling. I'd still run an aftermarket cooler, but run it through the radiator as well.

Wondering about the flow direction. Should you feed fro the bottom or top down? My cooler was mounted with both on the bottom and I think it was not filling the cooler so now I turned it 90 degress and feeding it from the side, but not sure if should feed from near the bottom and out near top or reverse.

It is my understanding you can "overcool" your tranny and you want the tranny fluid around 180. This allows all moisture to be "cooked" out. Running it through the radiator allows it to maintain a minimum temperature that will eliminate the over-cooling. I'd still run an aftermarket cooler, but run it through the radiator as well.

I never keep in the radiator and have run stand alone for many rigs.......including the MJ Im putting an AW4 in today........the key is an electric fan on an adjustable thermostat. I put it on the surface of the tranny cooler and set to 190*.......I have tranny setups like this with over 200,000 miles on em......so I guess it works.......I do leave them in the engine compartment to eliminate too much air flow and running too cool

Wondering about the flow direction. Should you feed fro the bottom or top down? My cooler was mounted with both on the bottom and I think it was not filling the cooler so now I turned it 90 degress and feeding it from the side, but not sure if should feed from near the bottom and out near top or reverse.

I would feed in the bottom and out the top, that way any frothing or air bubbles will go with the flow... my .02

Another idea if you're adding another cooler and worried about too long lines, is to install the second cooler in parallel to the first, instead of in series.

Also, go to full synthetic: If you're running that hot, you may have already cooked the fluid that's in there now, so replace it. Full synthetic might drop temps 5-10 more degrees.

Al

I have done many swaps using scat VW remote oil cooler setup as a stand alone unit, with electric fan and adjustable thermostat unit from imperial (checker auto) the whole setup costs about 160.00 and works with any tranny. I usually mount on the inner fender of the engine compartment

I will take and post up some pics later today......

http://www.fototime.com/%7B2A7B4841-D020-4212-B4D4-C795CEC52823%7D/picture.JPG