Squealing gearbox disco 2

[robin banks]

I've been asked by a friend to ask on here what would give the symptoms as in the video. It's not his video but his is doing the exact same.
Put it in drive or reverse you get this awful squealing. But put the transfer box in neutral and it doesn't squeal. It's a discovery 2 diesel automatic


https://youtu.be/kCSrMub0cSo

 

[Stock]

Input gear splines gone in the transfer box or a bearing on the output shaft ....................................................................................