Im building a early 3 speed trans for a customer. After completing the re-build the trans refuses to down shift back to first at slow speed (it never did to begin with). The transmission shop told my tech that first gear was not syncronized and that those early transmissions needed to be at a complete stop befor they would go back to first gear. Im trying to explain this to my customer and since he just baught the car he doesnt know anything about it but, he is sceptical that I am lieing to cover up poor workmanship.

HELP!!!!!