Trans cooler leak. 100% my fault.

Yes, I wish we still had transmission dipsticks.
So, a month or so ago, my MIL ( I gave her my Tacoma and got a 4Runner) was saying that the truck would bump intermittently when at a stop or pulling away from a stop. I drove it and it happened once or twice. First I suspected bad gas. Not it. Then I ran my Foxwell to see if there were any codes. Zero. Plugs, nope. Thought I would do a drain and fill on the trans. Ordered the WS and a new magnetic inline filter, as I installed a B&M supercooler back when I was towing a little bit. There it was, a tiny leak on the lower inlet hose that never made any spots on the ground, ever. After draining, I got about 2.5 quarts out. From most accounts, people are usually seeing about 3.5. Did the fill and set the level. Took about 3.5 qts, and of course, back to normal.
The morale of the story is, if I had a dipstick, it would have probably been the first thing I checked.
Live and learn.