Pulling trailer transmission issues. Any advice?

Hey guys, thanks for all the advice on the site. Having an issue with my 2002 2RZ AT with 250,000 miles WITH LCE supercharger.

Been doing some moving with a lot of back and forth trips. I have a 6x10 single axel trailer 80% full with household items. I've gotten about 2,000 miles with no issues at all, but this morning woke up to continue the haul and the transmission isn't shifting how it normally has been. It sticks in low gear on level land, revving beyond 45000 rpm with little to no power. It won't downshift at all, even when going downhill. It seems to be stuck in 2nd or 3rd when I force it with the gear shift. I don't know what's going on since it's been working fine for the last 2 weeks with no change in load size and no problem revving up and down the torque band. I took the trailer off to check, and it went back to having no issues. But as soon as I put the trailer on it continues with this new symptom. Besides air suspension and the supercharger, the truck is bonestock.

My first thought is it was doing fine at first, but due to the high mileage the transmission has had it. And at this point I'm inclined to just swap out with a lower mileage a44d or if there's a more robust option for the 2rz. Or maybe it's simpler, like a bad tps sensor.

Any thoughts are super appreciated, I'm a bit lost on what to do and I don't want to get rid of this truck because I've had it since it was new in 2002, and I need to be able to pull trailer loads. You guys have taught me lot since I've had to work on this truck, again thanks for all the advice.

 

I have watched enough Roadkill episodes to check tranny fluid level 1st

 

Do you have an external fluid cooler? Recommended for towing. In adding to checking the fluid level, verify the fluid is not degraded. Should be a bright/clear red.

 

I don't know your transmission, or how you've treated the truck, but I know with my 3.4 MT, I started pulling a 3,000lb trailer when it had 200,000 miles. Still pulling that trailer at 325,000 miles, and the tranny is holding up. In fact it's still got the original clutch. So the mileage it not necessarily an issue. But I don't know anything about ATs. I've definitely shortened the life of my truck by pulling this trailer, but it's surprisingly been up to the job.

 

I would start by checking the kick down cable. Odd for something like that to happen over night.

 

1. Do you tow in overdrive?
2. How much weight are you towing? Rating is not measured in household items or number of canoes.
3. The AT in the 1st gen is pathetic. I tried a DC up a steep grade no trailer once. It was the I knew a DC was not an option for me. The 5 sp pulls a small camper great.
4. If you love the truck and have gotten that much out of it, replace the tranny, read the towing Bible and gear crushers AT thread, and resume loving your truck.



Edit: holy crap I just realized you have a 4 banger. I got confused by another posters pic.

Get a tow truck, or a truck that can tow.

Not sure how many HP your SC adds or if you have all the fuel pump/trims and pulley mods. But betwewn that and I heavy load or over drive or both, it is likely your AT has essentially become the equivalent of a fuse in your powertrain, especially if that model AT is matched to 4 banger output.