Terrible noise in Opel Border 2.8

Hello! I have an Opel border 2.8 TDI with Isuzu motor that for a while to this part, how do I put the 4x4 traction, to get out of a sand, for example, I must take it away right away, because it costs a lot to wear the car, as if the rear axle were on its own, and also makes a deafening noise suddenly, as if it stepped on a large stone, and it is removed later. When putting back on two wheels, the car vibrates a barbarity for many kilometers and then disappears. A year ago that happened, I took him to the workshop and they told me that it was a bearing problem, that they changed, because the unlocking did not enter well.
What can be happening?
Thanks in advance

If that was already the problem in a Minoto, the most caused thing is that the same problem you want to change you anything but they only repaired it, there can happen generally, it happens that they do not enter or go well, and that is why they probate noises and bibations, it can also be that the crosses of the cardan either of the tranfer or the normal ones are in poor condition, or contamination of fat.