More than likely yes it will fit.
On a 1999 Mercury Sable : The transaxle ( transmission ) is located in the engine compartment , bolted to the engine
It was used in the previous generation Sable/Taurus (90's) with the 3.0 OHC Duratec engine and FWD Lincoln Continental's with the 4.6 V8. The two are probably not interchangeable and the gearing between the two is much different (at least in my experience). Would be nice to know if the two are interchangeable.
Inside the transmission
The Mercury Sable transmission has a fluid capacity of 12 quarts. You can use any SAE certified automatic transmission fluid.
yes
NO it don't. It is a electronic controlled transmission.
Replace your transmission pump or get a new transmission.
According to the 2000 Mercury Sable Owner Guide : ( Motorcraft MERCON - V , automatic transmission fluid in both types of automatic transaxle / transmission )
There is NO TIMING BELT on a 1995 Mercury Sable * Both the 3.0 and the 3.8 liter V6 engines in a 1995 Mercury Sable have a timing CHAIN
The 1995 Mercury Sable would have come from the factory with ( 5W-30 ) oil in the engines
Clean the 1994 Sable transmission at a car wash. This will make it easier to find the leak. Keeping the fluid full, check the transmission frequently to see where the leak is.
On the transmission.