Interim diagnosis: Differential bearings?

With another massive storm bearing down on us here in DC, I decided it
might be a good idea to have my mechanic have a listen to my truck and
tell me if it's safe to use 4WD over the weekend.

So Kenny takes it for a spin.  I do think he's trustworthy, but also
like to get verification when I have no knowledge of what a person's
talking about :)

He told me that when u-joints go out they tend to squeak?  Or something
similar.  That kinda got lost in what he said next - he thinks it's the
bearings in my differential?  Or, possible, the transfer case since that
has bearings as well... he said he can't know for sure until he opens
things up, but that he'd expect to find "shards of bearings all over".

A bit of googling says that noise on deceleration can be the
pinion-bearing preload has loosened (which means nothing to me); or a
failed pinion bearing - Kenny didn't mention this but he may have been
trying to keep this in layman's terms.

He highly recommended that I not use 4WD this weekend.  Said it'd be a
multi-day repair and might cost me $1500 depending on what's wrong.

So... what do you think?  Does this sound plausible?

So I'm really bummed.  I LOVE going out when the weather's so bad it
scares everybody witless (and believe me, most here are in a frothy
panic at the moment).  Big storm, snowy roads, everyone staying home
and... damn, so am I.  Grounded!

Hopefully I can get the thing in on Monday.  This area simply doesn't
have the number of snow plows needed to clear the roads quickly after a
really big storm, so we might be housebound for some days.  Especially
since there's another storm predicted for Tuesday.

I might even make some ccc's this weekend just to make me feel better,
and to stave off cabin fever.

Anyone else here battenin' down for the big storm?  I'm figuring since
everyone's well prepared for this one, it'll be a Big Fizzle.  Innit
that how things usually work?

jmc