Front End Banging - What Part Has Failed?

1994 NG 900 5-Door. I've got a constant banging from the front end, even on relatively smooth roads. It used to be only when it was cold, now it's all the time. When I pop the hood, and press down on the either side of the car, the center section of the shock/strut assembly, that has the big cupped washer and nut attached to the end of the strut, moves completely up out of the strut mount and does not appear to be attached to anything at all, on both sides, i.e., it is rising up and out as the car and spring seat are going down. When I do the same test on one of my other NG900s that has no banging, this part does not move up and in fact moves with the rest of the strut mount as it should. Is this bad strut mount assembly/upper spring seat? How horrible is taking all of this out? The struts inserts themselves were replaced previously and are not showing signs of needing replacement. I've disassembled and replaced strut assemblies before on Chrysler products which are only a few bolts getting them out, but I see something has to be separated with a ball joint tool on this one.