If you can't get it to stay... yeah tranny has to come back out. One of the prongs might be pushed up and its only catching one or something got bent up or who knows what. It should definitely stay in place on its own.
2000 Mustang GT Steeda #0048 34k miles. 99 Cobra 4V swapped, FTBR IRS swapped, exhaust, tuned by James Gordon.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.