Transmission pan gasket leaking/seeping fluid

I did a regular drain & fill this weekend, added about 4 quarts of WS ATF, checked the fill level and made sure the pan temp was in the right range while doing so by using a live data OBD scanner the way Toyota tells you to. Did not drop the pan or touch any of the pan bolts in the process.

When I was tightening up the fill plug, I noticed some oil seemingly seeping though the gasket around some parts of the pan. I dabbed it with a clean shop rag and confirmed that it was bright red, like the color of fresh transmission fluid. Unfortunately I didn't pay attention, and am not sure if the oil was already seeping out prior to exchanging the fluid.

Forgive my ignorance here, but this isn't normal right? It's possible the transmission is a little overfilled and I need to let some more out (a "slow trickle" from the check plug is sort of ambiguous), but either way shouldn't the outside of the transmission be completely free of oil?

It's not a fast leak or anything, it isn't even running all the way down the side of the pan yet or pooling on the driveway, but it seems like something that should be fixed. Would replacing the gasket be enough or is this a sign of something bigger being wrong with the transmission?

For reference, this is a 2019 4WD Tundra so the transmission unit in question is the 6 speed Aisin AB60F.

 

What side was it seeping from?? If it's on the same side of the fill hole, it can be assumed that some fluid dribbled out, making it appear its seeping through the gasket. I've reused my 2nd gasket and have 2 missing bolts on my 07 and it's been good so far.
If you don't feel comfortable having it seeping then keep an eye on it and on your next engine oil change swap the gasket out. I did say engine oil so you don't waste the new ATF fluid, by then it will be well mixed with the old fluid and allows for a fresh 6qts of oil.

 

Dumb question, but I'm asking for good reason. Are you sure the washer didn't fall off before installation? It's nearly the same size as the flat bolt head

 

As stated if it's on the same side as fill it could have dribbled out and dripping down. I run my ab60 with an additional quart of atf with no leakage.

 

To address some responses here, no it's not next to the fill hole. It's most pronounced on the side that faces the rear of the vehicle.
And to answer bflooks, both washers are on and it's not coming out from the fill or check holes, it's coming out of the rubber gasket that seals the entire transmission pan.

 

Pictures please

 

I’d probably just hit it w some degreaser and rinse off w a hose and run it for a bit to see what’s up, even if it was seeping a smidge, I’d probably go with it till it actually dripped.

 

Yeah, I've had fluid come out of the fill hole.and it runs along the pan surface to the rear. Clean the entire run as best you can, and repeat for a few days. I guess the summary is this: it's not unheard if, but time will tell if it is residual. You'll know what we mean if it stops. I say this as someone who didn't think there was very much at the seal, yet the drops appears to say otherwise on the garage floor overnight.

 

Photos as requested. The drain and check plug area were cleaned with brakcleen so they're discolored but aren't leaking any red fluid. But between the pan gasket and the pan I can see some oil.

 

Have you ever dropped the pan to change the strainer?

 

Nah, I've never dropped the pan on this truck. Previous owner might have, but it's not in the lengthy dealer maintenance log so I doubt it.

From what I've read, changing the strainer/filter usually isn't necessary on these unless you go really long without a fluid change?