I had to build a new filler tube for my 55 dual range hydromatic and have questions with the dipstick What issues are there with overfilling of the trans. I had some slippage when shifting from 2nd to 3rd. Put some more oil in it and it didn’t slip. I do think it might have more oil then required

 

Sounds more like out of adjustment than a low oil or to much oil issue unless it started out very low to begin with. The second to third shift is the most likely to give you a rougher shift than all the rest anyway. You might try an adjustment as prescribed in motor manual and see if the carb is giving the transmission the right information (it's all mechanical info), Or on the bad side your bands could be getting ready to give it up. Give the adjustment a try and se if that helps it's a cheap fix anyway. How much is too much I can't see the dipstick from here is it blowing out the dipstick hole yet?...Tedd