just example , I drove a 70 coronet , 318 / 904 with no kickdown (TP) rod on the engine or trans whatsoever for over 3 years , everyday. its not good for it , no. the car was still driving and shifting fine when I sold it. it sounds to me like "AAMCO" (the transmission wizards) did something else to it that caused it to fail . I don't see it completely failing after just a "few" days of not being hooked up , I could be wrong of course , but considering who was working on it , I would not be surprised
you will have to prove in a court of law that they were directly responsible for the failure. you will need all the paperwork and show that there is or was a guarantee on the work done and that it was still valid when it let go.
I hope you sue the **** out of them and win. AAMCO is a joke, this isn't the first time ive heard of their shoddy work and refusal to make it right
