904 Shift Problems

If the trouble started imediately after this burnout I would think you've stirred up some debrie that clogged something in the valve body. There are steel balls rolling back and forth in channels. If a ball was sent past where it normally travels it probably stuck there.
If you can rebuild an engine it's likely you can service the trans.To drop the valve body and seperate it to clean it requires a manual so the correct size balls go back in the correct places. May as well pplan on replacing the selector shaft seal though. That can be the hardest part of it.