Its probably your servo pin.

While on my bench I did a ton of pressing on the servo to get it to engage correctly, I even had to weld some material on the end to adjust length after I cut it too short!

I followed this short guide.
400/4L80 Band Adjustment

 

Also, my old drum was crazy worn. I had to get a new one.


Can't see, but lightly sanded to remove glaze and improve grip.

 

Thanks for the link. I'll test it out. I dropped the pan and pulled the servo. Found the c clip for the pin was bent into the piston cover. Almost like something tried yanking on the pin to pull it out of the cover. I have a spare pin but need to measure it. The original pin I damaged when removing from the piston, it was stuck in there pretty good. I attached pictures, hopefully can see what I'm talking about.




Original servo - marked up pretty good from removing pin.








Original pin on left





Do these lines mean anything?

 

Yea, those lines can tell you the length of the pin. Do you have an ATSG manual? That would help you determine what length pins you have.