Transmission acts like it's constantly trying to shift while in overdrive

2013. Auto. Truck shifts and runs fine in gears 1-4 but once it shifts into 5th / overdrive, once it's there, it keeps trying to lurch. Almost like it's still trying to shift. Kind of lurches. Hard to explain but it's only in 5th gear.

My first thing to do normally would be to check if it's low, but, these transmissions are such a pain in the butt to get to the proper level, I thought I'd ask if anyone had an idea. Tried the search feature but came up blank.

 

I would learn to do the proper level check. It's not the enigma that people make it out to be.

Sounds more like the torque converter locking and unlocking to me

 

I don't think it'll be hard either, I just thought there might be something simple and common that I wasn't aware of, which might be brought to my attention. My poor recollection tells me that it's something like removing the fill plug, getting all your tools ready, doing some sequence until the truck tells you it's in the right temp range, and filling it til it comes out of the fill plug. But, I haven't done it in ten years so I might be wrong.

 

You might be right on the tires, if it hadn't just started doing it last week. I've been running 33s for over a year now.

 

https://www.tacomaworld.com/threads/how-to-drain-refill-automatic-transmission.63851/

@gearcruncher

 

I guess I should clarify. The RPMs don't change when this happens. It stays the same. So, I guess I should say it probably is the torque converter doing its thing. But, is there a reason why it would be locking and unlocking - or is low fluid the go-to reason for its acting silly?

 

Is it possible you have a slight ignition misfire when the truck is under load?
Another possibility would be torque converter shudder but usually with that the tach will fluctuate slightly when it's occurring.
https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

 

^^ this

If the rpms aren't changing then it might not a slipping trans or TCC issue.

Scan it. Sometimes you'll feel a misfire for a bit before it codes