A COUPLE OF DAYS AGO I BACKED OUT OF MY GARAGE AND WHEN I STARTED TO GO FORWARD MY 82 300D WOULD NOT MOVE FORWARD OR REVERSE, I HAD IT REBUILT ABOUT 2 YEARS AGO AND WOULD APPRECIATE IF ANYONE COULD HELP,THANKS , DAN

Well Dan, if I were guessing, I'd say it's broken :D :D.
Seriously, if this happened suddenly and there were no early warning signs, I'd look at the linkage first. I have seen this happen a number of times. Wouldn't it be nice if were something simple like that. If it isn't the external linkage, it could be internal linkage. If it's internal, best left to a tech. Good luck my friend.