Inspection of a 904 torqueflite

glhx said
The thrust washer is stuck to the planets with the trans lube. I have to use a butter knife to remove it because it gets like a sticky vacuum seal to it.

What I’m thinking about doing is taking that extra output shaft that’s unloaded and putting the stack on it. Try to see where the space is coming from.

That’s part of the problem here is that I know all the pieces are in there.

The thrust washers are all new. The planets are original.
Both sun shells and gears behave the same with the same clearance problem.

I think more pictures and measuring is in order. I had to stop not long after I found the issue so I didn’t get too far with it. I would have had them both done tonight if I didn’t run into this.

Did you put both of the thrust plates on the sunshell that you replaced. There is a thrust plate and a thrust washer on both sides of the sunshell. Did you put both those in when you assembled the sun gear to the sunshell. With that amount of end play it sounds like you have missed one somewhere.
The thrust plates are large shiny silver discs that get assembled when you put the sun gear into the sunshell before you put the snap rings on that hold the sun gear into the sunshell. Take a picture for us of both sides of your sunshell as assembled.