Hard Shift On 904

ok so i have this swinger that i saved from a little old lady in 08. it had been sitting for at least 10 years in the same spot before that, and thats just as long as i can remember it. anyways it just ticked over 106K here a week ago, runs good, happy little car.

One thing its done since i got it is a hard 1-2 shift, like jaring. I can pull all the kickdown pressure out so it shifts a little better but my mpg falls like a brick. Something i noticed the other day was if you manual shift 1-2 after the D shift point its a perfect shift.

Only extra thing to add is it drains back really bad, after driving to work , 8am, till 5pm its got to fill again lol.

i was thinking of taking it to my tranny guy and have him do a shift kit so i could have him check and clean the vb, while adjusting bands. i can do the front bushing when i swap converters.

Any idea what would cause this?