Two problems related to transmission not engage have been reported for the 1996 Mercury Sable. The most recently reported issues are listed below.
When coming to a stop, the transmission would disengage out of drive into neutral. This has happened numerous times. Have been to dealer & so far nothing found.
During accelleration from stop to make left turn, transmission dissengaged. Rear bearing failure caused dissintegration of transmission. Dealer suspected faulty components/assembly but was unwilling to cover under warrantee which expired only 5000 miles earlier. Contacted manufacturer who claimed no responsibility.