JWRColorado

My mechanice says I have failing O-rings in auto trannie. Says it would be almost as expensive to replace them as to have have new trannie installed. Is this true?

At stops, trannie sometimes seems to slip into neutral. Only gear that works is reverse. After shifting several times into reverse, then neutral, then park, or in reverse order, it kicks back into drive. Only does this when car has been running for 10 minutes or longer. Any ideas?