I checked the small technical data book and found two references to rear axle housing:
Hex.-hd screws for mounting left rear axle tube with bearing flange at rear axle housing. M8 - 2.5 mkp (18 ft-lbs), M10 - 5 mkp (36 ft-lbs)
Hex.-hd screws for mounting cover at front of rear axle housing - 3.5 mkp (25 ft lbs)