4 Wheel Drive/SUVs: 97 Explorer Front Differential

Question
My question is more general in nature I believe.  Now, this may sound like a pretty screwed up idea, I'm hoping you will know if it's technically possible.  I have a 97 Explorer AWD that has not had the front drive axle connected for about a year now, working perfectly fine, I even drove it from California to North Carolina in December '13 - no issues whatsoever.  What's started happening this past week is that what was a thumping sound quickly progressed to a scraping, then grinding/crunching sound.  I didn't initialy concern myself too much, thinking it was separated brake pads or rotors.  Well I got to a mechanic when it got to sound pretty crazy (truck still moving/running perfectly fine just the new added noise feature) and the mechanic is certain that its the front diff.  Having removed the shaft from the transfer case to the front diff some time ago, I hadn't given much thought to the idea that the gears and everything would keep spinning with the wheels.   MY QUESTION(in case you wanted to skip the explanation);would it be feasable/at all possibe to just remove the synchros from inside the front differential, leaving the drive axles? Could that be done without removing the axle/axles?  I knw it sounds abusive as a responsible owner, but the truck is pretty much rusted out underneath(not typical rust, mechanic afraid to put on a lift type of rust), I'm not sure how much more to invest in the vehicle, and at minimum this would be a fix while I try to locate a compatible front diff and have it installed.

Answer
Marcus,
OK, first of all, there are no "synchros" in a differential.  Synchros are used in transmissions to assist in shifting from one gear to another without grinding.  As long as there was oil in the front differential, there should be no problem.  You need to leave the internal gears in the differential, as they also support the axles.  You may be able to get a manual hub set up off of another Explorer at a wrecking yard.  If you install the manual hubs, then all you need to do is turn the hubs out, which would put the front wheels into a free wheel mode.  This way they wouldn't be turning the axles at all.

Carl