Transmission oil: How full is too full?

[Coronado126]

(11-26-2020 )Meanwhile Wrote:  Thank you, that’s good to know. Today I decided to clean up some oil and make sure there’s nothing leaking. I’m pretty sure this trans cooler has coolant running to it, since it has blue silicone hose on the one side. I pulled the plug on the transmission to check the oil level and it didn’t run out. I can touch it with my finger easily. I’m guessing I’ll be ok to run it a couple days until I can find some more oil?

It's more than likely perfectly fine.

I can't find the drawing I used to have, but stick your finger straight in just past the 2nd knuckle, and bend your finger down roughly ~1". If you can touch fluid you are good. Anymore than that and you need to top off until it is level with the fill plug hole.

The above applies to autoshift (not real automatics!!) and manual transmissions, and differentials on semi's.