Installing tranny cooler, tranny temp gauge

[Moser97]

Can someone tell me which line from the trans to the radiator is the pressure side and which is return, on a '99 Jimmy? I want to install a cooler in the return line and a transmission temp gauge in the pressure line where the fluid should be at it's hottest. I am also interested in opinions on how best to run the cooler. Some guys say before the radiator, some say after the radiator, some say bypass the radiator all together. What say you?

[OverBoardProject]

I would only bypass the rad if you have a monster of a cooler. I believe that's what Dodge does with some of their big pickups.
Sorry I don't know which side does what

[Moser97]

Thanks OBP. I think I will try to put the cooler in the return line from the radiator first. I'll put the gauge in the pressure line to the radiator. I'll just pull the top line off and start the car. If juice comes out the line that's the pressure side. If juice comes out the radiator it's the return side. If I find I've got 150 degree fluid going to the radiator only to be heated up to 195F I'll bypass the radiator. I got a B&M 24000 GVW cooler from Shawn on here. It is not huge, about 8 inches by 10 inches. When the alternator went out the other night, I had a good talk with the tow company owner about pulling that big hill (3 miles, 7% grade) between here and work with a load. He said the most important thing to him is the ability to lock up the torque convertor. He showed me temps over 250F that fell to 165F within 500 feet of him locking up the TC. I played around with the Tow/Haul button tonight coming home from work and I'm pretty sure it is locking up the TC when you activate it. I will see more and post again when I get the cooler and gauge in and run the mountain a few times with and without the boat on.

[OverBoardProject]

I'm looking forward to seeing your findings, and might copy some of your work. I don't think that I can lock up the torque converter on my 85, but since I tow a trailer through some steep trails I'd like to help it run cooler.

[Eslhockey92g]

I was thinking about getting the exact same thing for my 97 blazer. I wanted to do a trans temp gauge and cooler. What do u do to get the trans temp. Like what gets wired to find the temp or is there like a sensor that gets put in or on the line? Any one know

[OverBoardProject]

I would make a T fitting out of plumbing parts that'll allow me to splice into the oil lines, and get a 2 wire oil temputure sending unit for this setup (The second wire usually goes to ground, since the T probably won't be grounded when your done). Run the gauge inside wherever you want it, and wire it up according to the hopefully enclosed instructions.

[Eslhockey92g]

can i cut out a large section of the metal trans tube, and use a heavy duty rubber hose to make up the differnce with a t fitting spliced in that, or should it be a metal splice?

[OverBoardProject]

My plans are to just use rubber transmission hose. Rubber fuel line isn't designed for the temputure of the transmissing oil so make sure that it's transmission hose that you buy. They look the same to me.

[Eslhockey92g]

Thank you once i get done school, that will be one of the first things done

[s10blazerman4x4]

We had it in front of rad passenger side with the connections like facing vertical not horizontal.


How did it get to ya? I thought all trans fluid was out but i noticed before shipping it wasnt haha i dont know how so i bagged it.

[OverBoardProject]

I try usig 20 lbs of compressed air or so to clean out of such things

[s10blazerman4x4]

I dont have compressed air haha. Link to the cooler man got haha minus 99 percent of the install kit, it was used on truck.
http://www.amazon.com/gp/product/B00...nce&n=15684181

[muddog321]

Heres an article with a pic on install:
http://www.hotrod.com/techarticles/44618/

You must have added a tow/haul switch on the Jimmy cause I never saw one on the S-10 size Jimmy/Blazer before, only full size. GM states never use "D" or overdrive when towing heavy loads due to heat so put it in "3".

[Moser97]

Great article Muddog, I did a Google on trans cooler installation last night and found several like it. The cooler goes in the return line according to most of the articles. That's where I'll put mine. The Jimmy came with the Tow/Haul button from the factory, if it was an option I can't say. It was a lease vehicle and I bought it from the second owner.
I plan to use a 1/2 or 3/4 "T" reduced down to accept 3/8 hose fittings plumbed into the pressure line as close to the trans as I can get for the gauge. I may bring the gauge wire up from the bottom thru the trans hump if it will come up thru there easier. Ideally I would pull the trans pan and take it to work and have a half coupling welded in and then put the temp probe right into the pan. If I ever get the pan off and can do without the car for a while that's what I'll do and then move the probe. The reason for reducing down a bigger T is to make sure I get the probe into the fluid flow without restricting it.
Blazerman the cooler got a few layers of shrink wrap from somewhere to seal it up, so it arrived in good shape, with a pretty soaked envelope but the package was intact. I want to get the cooler on but I'd like to put the gauge in and run it a week, then put on the cooler to see what difference it makes. I'll take some pix of the gauge setup and try to post them.

[OverBoardProject]

Originally Posted by Moser97

Ideally I would pull the trans pan and take it to work and have a half coupling welded in and then put the temp probe right into the pan.

What a good idea, I never thought of that.

I've got 2 vehicles, so I can afford the down time, I think that I'll use this idea on mine.

That way I'll also be able to drain the transmisssion oil easily when I want to.

I wouldn't mind also having another gauge in the return line