vibration problems with jeep

having problems finding anyone with knowledge on the process gear 247 j
transfer case in the little town where i live.originally took it in and
they said rear u joints were bad.replaced them vibration got worse.went
back they said maybe it was a bearing in the tranfer case.they told me to
take the extension housing off of the transfer case and there should be a
bearing there to replace that bearing.so i bought three different manuals
and none of the manuals actually shows my transfer case.is it actually
possible to remove the cover and replace the bearing or is this more like
a rebuild job?all we have here in town is an autozone and they have been
more cofusing than anything not very knowledgeable.after spending alot of
money between what the auto parts said and the garage we had look at it
the new thing they tell me is that they don't actually know they never
worked on the 247 j.that it is an oddball transfer case is this true?it's
our only mode of transportation trying to fix it to get to work.would
greatly appreciate any help with this not getting anything but alot of i
don't knows here.wish they would have told me that before i spent so much
money.they sold me a bunch of parts that weren't the right ones now they
are saying everything for it are dealer items is this true?one mechanic
tried to tell me he had never heard of the bearings going bad in the
transfer case???Please need help first jeep we ever had don't know what
else to do don't have the money to take it to the dealership and have it
fixed.