Tci 727 question

In my coronet I have a TCI street fighter 727 its been great for about 16 years zero issues. Few weeks ago I was going to a show and generally I shift it manually up into drive and I shifted to 2nd and it was just like I hit neutral. Low and 3rd still shift firm like always. Reverse works good to. I changed fluid and filter after and outcome still the same. I've wrecked a few 727s and usually when they break all gears go at once any one have any ideas before I pull it out?
What did the filter look like when you pulled it off? What kind of debris was in the pan?