My truck is a 92 HDJ81 with the full hydro A442F, running into some issues towing my travel trailer with it. I currently have a dedicated 34 row Derale stacked plate cooler attached to the transmission and disconnected from the radiator, I only run into heat issues when I am pulling the trailer up steep inclines here in the PNW (usually makes it through 3 or so 5% or greater grades (each quite a few miles in length, 4-5 miles or so) I have had the overheat light come on a couple of times (truck is not in OD during this), it cools off quickly enough and I am able to carry on so long as I keep the speeds up or allow it to kick into overdrive. Trailer weighs 3k lbs (I don't fill it with water etc...) empty and 3200lbs with minimal stuff inside the trailer.
I have flushed all the ATF out (multiple times to ensure it's fresh when this happens), last year when it was attached to the radiator and a smaller (9 row stacked plate Derale aux cooler) it caused my radiator to boil over (but the ATF light never came on) when towing. Removing it from the radiator (I installed a 4 row manual trans radiator) fixed those issues, and so long as I tow on less steep grades or at highway speeds it doesn't overheat the transmission. Without towing I can do slow rock crawling to whatever just fine with no heat issues all day in 100 degree weather. I don't have a temp gauge yet, but I do have one on order. Fan clutch hub has been replaced with a new OEM one, and has heavier oil in it (it works great at keeping things cool). Installing a hefty electric fan to the trans cooler to help a bit as well.
My question is this, is the torque converter to blame for it getting too hot (it locks up fine in 4th) along with it being removed from the radiator? Should I get an auto trans radiator and hook it back up properly? I've seen other HDJ81s towing heavier trailers than mine in the PNW (autos) to the same areas and they don't have the issues I have, so I'm just trying to figure out if I need to drop the trans and replace the torque converter, or really double down on cooling for it.
I have flushed all the ATF out (multiple times to ensure it's fresh when this happens), last year when it was attached to the radiator and a smaller (9 row stacked plate Derale aux cooler) it caused my radiator to boil over (but the ATF light never came on) when towing. Removing it from the radiator (I installed a 4 row manual trans radiator) fixed those issues, and so long as I tow on less steep grades or at highway speeds it doesn't overheat the transmission. Without towing I can do slow rock crawling to whatever just fine with no heat issues all day in 100 degree weather. I don't have a temp gauge yet, but I do have one on order. Fan clutch hub has been replaced with a new OEM one, and has heavier oil in it (it works great at keeping things cool). Installing a hefty electric fan to the trans cooler to help a bit as well.
My question is this, is the torque converter to blame for it getting too hot (it locks up fine in 4th) along with it being removed from the radiator? Should I get an auto trans radiator and hook it back up properly? I've seen other HDJ81s towing heavier trailers than mine in the PNW (autos) to the same areas and they don't have the issues I have, so I'm just trying to figure out if I need to drop the trans and replace the torque converter, or really double down on cooling for it.