My crown vic want shift into4th

Have you checked the transmission fluid level using the correct procedure? Have you looked at the condition of the fluid? If it is full of fluid you may have an issue that needs to be looked at by a competent transmission specialist.

Need to know the mileage. Could be dirty fluid/filter like Bob mentions, or worn torque converter. You should not drive with the OD off, you are sacrificing gas mileage and needlessly running engine at higher RPMs. With OD on TC clutch will lock at cruising speeds for a 1:1 power xfer from engine.

Wat year trans can i use in my 97 police interceptor

Why won't my crown vic drive

You shift it into reverse the car won’t move put in drive then you can back up