it can be a trans. mount (pull down real hard on tail shaft it should flex
down, not already be on the crossmember, then see if there is just a
little side to side flex) you may have a "carrier bearing" it's a flex joint
to support a long drive shaft( move up/down/side/side) it shouldn't move
to much . u-joints are checked about the same as the carrier, apply the
pressure with a small pry bar, DO ALL THIS on flat ground with wheels
chocked so there is no load on drive-line work safe, get a shop manual
to understand this better
