Morning Steve
Welcome to the Forum
Just check on www.realoem.com put the last 7 digits of your Vin into the search box it will call up your model then look for what you need probably front axel section. Double click the part number and if the were any alternates it will show a list.
Take care as there could be a few ratio choices 3.73-1 3.08-1 The next challenge will be getting your hands on one at a reasonable price BMW tend to only sup[y exchange units at 4 figure sums plus fitting. So check out the specialist Dismantlers
Dave