Thanks, grcauto. I see on page 75 of the ATSG 'The output gear tapered roller bearings must have a preload of .02 to .05 millimeter (.0008 to .002 inch). I have not done this before so this will be new,
The differential is a very necessary adjustment which is what you are looking at on page 75. Also make sure the the end play is correct using the correct thrust plate for the 2/4 clutch described on page 56 and 57. End play in the shafts is what wipes planets. Don't short the thrust plate or preload. Also that bushings are good so the shafts do not have excessive side to side movement. Most can be done by feel and common sense.
There are good videos on you tube from guys that do total overhauls. Might be good to view one or two if you have a couple hours.
Need to be aware of one or two snap rings (tappered or beveled) as they only go in one way and I think there may be something else that is critical for which way it's installed. Take your time and read each step and you'll be good.
The comment about the bearing pre-load in ATSG is in regards to the output gear. It's just a small blurb on page 75. I would be doing nothing with the diff. So I guess I just put a feeler gauge in between the gear and the case? Re: input clearance, it's done on the input drum, not the 2/4. I assume a cheapo hand-held dial indicator would do the job? Never done this stuff...yes, the UD and L/R pressure plates both have a beveled upper snap ring that must be oriented correctly. Hard for me to see the bevel but it's there. Yeah, on that core, I had installed that tranny in another van but used a different pump and converter, and it still made the whining sound. If I could be sure it was either the stripped front planet or something in the valve body, then I would build that tranny up and avoid all this stuff with the rear planet.
If you are not doing anything with the diff just pry and check for any excess play on the ring and side gears. If they are pretty tight I would not worry about shims. As for the output gear bearing if you can't tell there's movement you are probably good. I'm not sure I remember ever trying to use a feeler on one while assembled. If they had any movement we tore them down and used dial indicators to rebuild with new shims. Been several years since I've done any transmissions and my memory isn't the best.