BMW F97 - Page 34

F97/F98�Complete�Vehicle
4.�Powertrain
30
The�Service�employee�can�move�the�oil�bulkhead�to�the�open�position�by�means�of�the�“Service
function�>�Transfer�box�VTG�>�Oil�change”�in�the�BMW�ISTA�diagnosis�system.
Current�transfer�box�oil�recommendations�and�capacities�can�be�found�in�the�current�documentation�of
the�BMW�workshop�information�systems.
4.3.5.�Active�M�differential
The�active�M�differential�on�the�rear�axle�is�an�integral�part�of�the�M�xDrive.
This�electronically/electromechanically�controlled�M�rear�differential�lock�was�developed�specifically
for�the�F10�M5�and�is�also�used�on�the�F06/F12/F13�M6,�F80/F82/F83/F87,�F90�and�now�on�the�new
F97/F98.
The�active�M�differential�has�been�reworked�for�the�F97/F98,�which�specifically�involved�adapting�the
rear�differential�housing�to�the�rear�suspension�subframe�of�the�F97/F98.
The�M�rear�axle�differential,�size�HAG�225�(crown�wheel��225�mm),�is�used�with�a�M�rear�axle
differential�lock.�The�system�designation�is�"M�regulated�rear�differential�lock"�and�accordingly�the
control�unit�designation�is�M�GHAS.�
The�gear�ratio�of�the�rear�axle�differential�HAG�225�is�3.154:1.
This�M�rear�axle�differential�can�be�recognized�by�an�aluminum�oil�sump�assembled�from�below�and�an
electric�motor�which�is�visible�from�the�outside.
The�HAG�225�weighs�43�kg.