If you use the Search facility and read the many posts on this subject you will get a better understanding of the available options. Sometimes Vauxhall UK offers a contribution. Bottom line is be prepared to get your cheque book out; the sum involved seems to vary wildly. If you didn't know, other brands have transfer box issues too and it is claimed that unequal tyre tread thickness can cause a failure. Good Luck and do post the outcome for others to see.
2015 2.2 CDTi SENav 163ps manual 4x4 in Carbon Flash with 19\" alloy spare towing a Bailey Unicorn III Madrid @ 1500kg.