1990 Towing and transmission cooler?

So,
Now that I have this cooling thing figured out, I was thinking about so other issues. I would like to use this Jeep (1990 4L) to tow about 3000lbs about five times a year. These trips will be at max 1000 miles in the mountains. The PO has a hitch tied to the bumper, so I thought I would replace that with the standard under the bumper hitch, maybe from a junk yard.

My real question is, I noticed that there is already lines running from the radiator to the tranny (AW4), is this considered a transmission cooler? If not, what was the factory towing setup? What do you recommend? The rig has 250k on it, so is it a good idea to use it for towing? I have a '04 GC with a 4L, but would rather keep the miles off of it, however, I will be using it to tow the trailer this weekend.

Thanks in advance for your help.
Bob

You will definately need a transmission cooler when towing. The lines running from the trans to the radiator are not adequate cooling, but are there more to have the fluid warm up in cold temperatures. I am currently in the process of installing a transmission cooler (B&M supercooler #70268) on my 97XJ so that I can tow my 3500# trailer. You will want to keep your transmission cool. Heat is the biggest killer of these transmissions and a quick way to heat your transmission is putting the added stress of towing on it.

Also, per my experience, make sure your regular cooling sytem is up to par. Probably a good idea to flush out the cooling system before you go if you have not done that recently. My XJ got pretty hot towing my trailer through the mountians.

And for a trailer with that much weight, make sure you get a decent hitch. I have a class III hitch on mine and it works well.

So, if you are adding a cooler, are you mounting it in the stock location or somewhere else? Are you going to bypass the radiator or put it inline?

Any reason you went with that cooler or does anyone else have some recommendations?

Thanks,
Bob

cherokee4fun said:

So, if you are adding a cooler, are you mounting it in the stock location or somewhere else? Are you going to bypass the radiator or put it inline?

Any reason you went with that cooler or does anyone else have some recommendations?

Thanks,
Bob

Click to expand...

The aftermarket cooler recommended above is to be installed in front of the radiator. That cooler is large enough for a 4L towing what you stated you want to tow. Any name brand suchas Hayden or B&M are of a good quality. Do not circumvent the factory cooler built into the radiator. You live where it gets cold enough in the winter to require some tranny fluid heating as well as cooling in the summer, so leave the current setup. Supplement what is already there.Just my 2 cents worth.

X2...What he said.

I will not be changing the routing that goes to the radiator. Just adding this cooler to the flow. I will be mounting it on the front on the mechanical fan side.

Unless you mount a fan on the T cooler it self. It almost must go in front of the mec fan.
The trany will generate most of it's heat in stop and go traffic or pulling big hills and towing heavy. This is also when natural air flow is low. Without some kind of fan to improve air flow at low speeds the add-on cooler becomes near useless.
If it's important? It's the torque converter that generates 90~95 % of any auto trany heat.

Would I use a XJ with 250 k on her for towing? No, but that's me.

Beware of used hitches. I just whiz wheeled the original factory hitch off of my '90, 'cause it had literally rusted through. The tube was delaminating & swelling and actually broke off in places. I know you won't buy something like that, but check out any "surface rust" real close. You will need the nut strip for the driver side, and will need to remove the bumper. Good time to check out those brackets as well.

And yeah, what they all said about the cooler.