1996 Subaru Legacy automatic; Drive Shaft intermediate Support Bearing & Transfer Duty Solenoid, problems

[subyworkshard]

I have a bad vibration and knocking from the rear or centre of the car when accelerating. Through my process of elimination and visual inspections and pry testing I think the centre drive shaft support bearing is causing the bad vibration/knocking. I cannot find a drive shaft Intermediate support bearing, or an affordable drive shaft. So, I tried to switch my AWD to FWD only, but it appears the 'transfer duty solenoid' is not functioning. When I install the fuse to hold the solenoid switch in place the dash light says FWD but I still get acceleration power to the rear wheels/driveshaft. There is no vibration / knocking when coasting at any speed. So, I think, if I can it in FWD only my problem would be resolved, for a while at least. I cannot find a new replacement solenoid, so can anyone suggest where I can find or what I can do to run it in FWD only? And could someone tell me where the 'duty transfer solenoid' is located and is it easy enough for a mechanically minded DIY'r to replace?