Be Prepare for Anything
I work all my life in my cars doing any kind of work and replace the rear bearings of my 645 was a lot harder than i thought.
I also have the bimmer electronic service manuals and follow all the instructions but the puller to pull the bearings that show in the manual does not work for me i have to build my own tool.
According to the manual you do not have to remove the axles but that the only way i was able to do it. Removing the axles and the exhaust to have some room to pull the axles back and give the right torque.
The truth is that you do not remove the axles you disconnected from the cage and pull it down a little bit to gain access to the bolts that hold the bearings from the rear. And you need to move the axles especially to tight the new bearings at the right torque.
If you still havenít do the job you may have to buy some extra bolts the service manual recommend replace all the bolts and some may get striped also I replace the Hub that was not in the original idea but I fight so much with the puller that I worry may bend and after I replace the bearing the hub warble and I have to do the job again and get another set of bearings. So I put everything new you need the press the bearings to the hub with a 5 inch vice and lot of invention, you have to press the bearing from the inside to get it press in to the hub if not you ruin the bearings.
I believe that the dealer sell the bearings already pressed in a hub that save you some time and headache, I was not able to do it because I order only the bearings and after confront the problems I order all the new bolts and the hubs.
You may have to find or rent a torque wrench that can go up to 350 foot pound, that one is to tight the axle nut, I believe goes at 320 foot pound.
This is a picture of the rustic tool I build because the puller I start using same as the one in the service manual broke and I have to buy the rented tool and lost $50.00 paying for the broken tool.