Fault-tracing information

Condition 

Fig 1: Identifying Rear Differential And Drive Shafts

Courtesy of VOLVO CARS OF NORTH AMERICA.

Applies only to cars with All-wheel drive (AWD).

Possible Source 

• The freewheel engagement/release mechanism in the viscous coupling is faulty.

Fault symptom[s] 

• No freewheel when reversing.