Most likely you have a problem with the torque converter or the valve body in the transmission. If you have around 85,000-120,000 miles on your Sable/Taurus, this is a common issue. Having a transmission specialist look at the vehicle is an expensive but necessary pitfall.
MY 98 HAD A BROKEN CLIP ON FORWARD CLUTCH VALVE SPOOL IN VALVE BODY
It is inside the transmission, on the valve body.
Inside the transmission, on the valve body.Inside the transmission, on the valve body.
Inside the transmission, on the valve body.Inside the transmission, on the valve body.
Inside the transmission, on the valve body.Inside the transmission, on the valve body.
It is inside the transmission, on the valve body.It is inside the transmission, on the valve body.
Inside the transmission, on the valve body.Inside the transmission, on the valve body.
Inside the transmission, on the valve body.Inside the transmission, on the valve body.
On the valve body inside the transmission.On the valve body inside the transmission.
Inside the transmission, on the valve body.Inside the transmission, on the valve body.
It is inside the transmission, on the valve body.It is inside the transmission, on the valve body.