Tech Brief – Buying or own a used Volvo with 70K-120K miles? Make sure the All Wheel Drive System (AWD) is working, in fact, this may be something that you want your servicing shop or dealer to check the next time your Volvo is in for service. Over the past few months we’ve seen a total of 3 of these cars, all in the 70K-120K mile range, with inactive AWD. We check the AWD system each service, but if you are taking your Volvo to a general repair facility, then you may want to show them this article, unless you know what to look for it can be easy to miss.

Amazingly this problem does not turn on any warning lights or set a computer fault code, the only way you can tell, other than by an through inspection in the workshop, is by a loss of traction, the front wheels have drive power, the rears do not. In one case the problem was noted during a vehicle maintenance, on the other two – only when the owners brought the car in with a concern about a lack of traction.

Fortunately the repair is quite straightforward, if caught early. It consists of installing a revised or reinforced coupler from Volvo, yes, they seem to have updated the part design. Given the overall dependability of the Volvo AWD/AOC system, and the mileage at which these failures occurred, this is not a terrible fault. We think of the coupler as a form of a “mechanical fuse”, protecting the more expensive driveline components from failure.

Overview of car

Coupler with Angle Drive Removed

Side view of Coupler and Transaxle

View of Coupler and Transaxle Output

Side view of Coupler and Transaxle

Angle Drive Gearbox

Angle Drive - Output shaft flange

Input to Angle Drive - Note splined shaft

Wore Coupler - Brownish material is rust, note extreme spline wear

Worn Coupler - Cleaned to show deeply worn splines