1996 AW4 running hot, like 220+ hot!

A little background: I'm running 35's, geared 4.88. This is my second transmission/TC combo doing the same thing(this trans ran cool in the jeep it came out of). I have a fan cooled auxiliary cooler inside the front crossmember and behind the winch bumper. Not an ideal location but space is tight.

With my infrared temp gun I get 220 at the pan, but at the cooler I'm getting 190 in, and 180 out. This is driving in 80* temps, normal stop and go city driving.

The fluid is fresh, still red, does not smell burnt. Dex/Merc 3.

I feel that I'm not cooling the fluid enough. There doesn't seem to be anything wrong with the trans. It shifts fine, does not slip, will lock up in d and od just fine.


My thoughts are to get the fittings from jegs and do away with the QDs, run braided lines to the front and try to get my cooler into fresh air, maybe even out on the bumper above the winch. I'm at a loss as to why the cooler isn't doing its job better. The lines have been removed and blown out to make sure they are not stopped up.

Is there anything else, internal to the trans, that could cause it to run hot?

Like I said above, two low mileage used trans/TC's in a row and I still have a hot running trans. It's got to be how its cooling(or not cooling)

I'm lost on this and ready to take drastic measures to get this rig back on the trail and reliable again

Important to note, I moved the trans cooler to below the radiator due to engine cooling issues. I have a winch bumper that blocks a lot of air on the trails. Fixed that issue, then the trans started running hot.

I do not have the cooler lines routed through the radiator.

You left out the important part, what cooler are you running?

RCP Phx said:

You left out the important part, what cooler are you running?

Click to expand...

Right now a stacked plate 8x12 with a 6" fan pushing on it

I have a really nice 24" finned cooler that I have thought about mounting above the winch. I just hate sticking that hot thing out there in the way of doing trail repairs or someone laying a hand on it

I have a 24" version of this cooler that I might try next, but in fresh air out front: https://www.google.com/shopping/pro...&ved=0ahUKEwiovL-2ycTcAhWJhlQKHa4WCvcQgTYI3AQ

Is your torque converter locking up properly. I have my temp gauge installed at the fitting in the trans near the forward cooler line. I assume it's on the hot side of the cooler. If I'm doing in town driving I see about 160-180 but it drops low on the highway. I have a big cooler in front of the radiator, not running thru the radiator. I personally would be more concerned with the hot side cooler temp over the pan temp. Are you getting any radiant heat from the exhaust on the pan affecting your temp reading?

Honestly, I dont think I'm moving the fluid as well as it should. Thus the cooler is ineffective, but I dont know the inner workings of the AW4 enough to answer my question

How can I test line pressure to the cooler? I have all the test guage (I'm a industrial equipment tech)

I hear line pressure should be 50psi, but cant find info to verify this

trippled said:

Is your torque converter locking up properly. I have my temp gauge installed at the fitting in the trans near the forward cooler line. I assume it's on the hot side of the cooler. If I'm doing in town driving I see about 160-180 but it drops low on the highway. I have a big cooler in front of the radiator, not running thru the radiator. I personally would be more concerned with the hot side cooler temp over the pan temp. Are you getting any radiant heat from the exhaust on the pan affecting your temp reading?

Click to expand...

Exhaust is also a concern, as we all know, it's right below the pan. I've tried reading on the left side of the pan away from the exhaust, I get similar temps.

xjtrailrider said:

Right now a stacked plate 8x12 with a 6" fan pushing on it

I have a really nice 24" finned cooler that I have thought about mounting above the winch. I just hate sticking that hot thing out there in the way of doing trail repairs or someone laying a hand on it

Click to expand...

A electric fan does not guaranty air flow because of the high/low pressure points. Take a pic of your set-up. Here's my 2000 been "about" like this for 18yrs with heavy mountain towing!
AN thread: https://naxja.org/forum/showthread.php?t=1148286
PS thread: https://naxja.org/forum/showthread.php?t=1148990

Here it is with the winch on!

RCP Phx said:

A electric fan does not guaranty air flow because of the high/low pressure points. Take a pic of your set-up. Here's my 2000 been "about" like this for 18yrs with heavy mountain towing!
AN thread: https://naxja.org/forum/showthread.php?t=1148286
PS thread: https://naxja.org/forum/showthread.php?t=1148990

Click to expand...

I wish I could see mine to get a pic. Its sandwiched between the winch bumber and engine skid.

My last set up was like yours but I had engine over heating issues so I changed things. Now the engine runs as it should. The trans runs hot now

What make/model cooler is it? But it sounds like a air-flow problem.
If your pulling air from the engine compartment, to hot!
If your trying to pull air from under the Jeep and push into a high pressure area, not going to work either!

RCP Phx said:

What make/model cooler is it? But it sounds like a air-flow problem.
If your pulling air from the engine compartment, to hot!
If your trying to pull air from under the Jeep and push into a high pressure area, not going to work either!

Click to expand...

This is what I'm thinking too. But what are my mounting options. I kind of want to go with this cooler that I bought and haven't used, its 24" long, about 4" in diameter

Has anyone mounted a cooler in a non traditional location? If so, give me ideas!