Subaru Forester: Rear Axle Half-Shaft CV Boot Failure

The rear drive axle half-shafts on all-wheel-drive Foresters use rubber constant-velocity (CV) joint boots to retain grease and exclude road contamination. The inboard and outboard boots on the rear shafts are subjected to heat from the exhaust system, road debris impact, and continuous flexing through the suspension travel range typical of the Forester's elevated ride height. Boot failure is accelerating by the lack of a protective undertray on many variants. Once the boot tears, grease is ejected centrifugally and the CV joint begins to run dry, leading to joint wear and eventual failure. This is a consumable item but is frequently missed at WOF inspections until the joint itself is damaged.

• Clicking or clunking noise from the rear of the vehicle during tight low-speed turning manoeuvres, indicating a dry or damaged CV joint
• Grease splatter visible on the inside of the rear wheel rim, on the suspension components, or on the underside of the rear bumper
• Torn, split, or collapsed rubber boot visible when inspecting the rear driveshafts from underneath the vehicle
• Vibration through the floor or rear seat at highway speed that worsens progressively as the joint degrades

Run a finger along the boot surface and check for grease film on adjacent components. With the vehicle on the ground, perform slow tight turns in both directions while listening for clicking. Spin each rear wheel by hand and feel for roughness or binding in the CV joint. If a workshop inspection is possible: Raise the vehicle and inspect all four CV boots on both rear half-shafts with a torch — look for cracks, splits, or boot clips that have come loose.

Parts involved: CV joint and boot.

$280 to $750 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “Have the rear CV boots been inspected recently, and are all four in good condition?”
• “Is there any clicking noise from the rear when turning in a tight circle at low speed?”
• “Has any grease been noticed on the inside of the rear wheels?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.