Necessary preliminary work:
Release connector (1) and remove.
Slacken nut (2).
Disconnect positive battery cable from alternator.
Slacken nut (1).
Remove cover from idler pulley and undo bolt (1) beneath it.
Remove idler pulley.
Release screws (1).
Feed out alternator upwards and remove.
NOTE: Check stored fault messages.
Delete fault memory.
BMW X3 Service & Repair Manual > Final drive: Removing and installing/replacing rear differential
Special tools required:
33 5 206
33 5 200
33 5 120
33 5 125
33 5 123
33 5 121
33 5 124
33 5 126
33 5 122
33 5 127
WARNING: Danger of injury!
Rear axle differential must be lashed with tensioning strap 33 5 206 to prevent it
from dropping down when pressing the output shaft ...