I don't have any answers for you, but I'm going to bump this to the top in hopes that someone else will. I'm looking for the same info for my 86 300E. It actually doesn't have a problem yet, but it's got about 155K mi. on it and I'm pulling it out to repair some leaks, so I'd like to know what I can or should replace while I have it out. Can much of the innards be gotten at or put back together without special tools, or are there some special tools that are a must?

Fwiw, I recently downloaded and printed the service manual for the 722.3 & 722.4 transmissions from ATSG.com. Here's a link to the order page. . The price is $25 for either download or hardcopy. I got the download version. It seems fairly complete and well laid out.

Gary