Nissan Patrol: Y61 GU transfer case drive chain wear

The Y61 GU Patrol transfer case uses an internal drive chain to distribute torque between the front and rear outputs. The chain is lubricated by the transfer case oil, and over high mileage — especially where oil changes have been neglected or the vehicle has been used heavily in 4WD — the chain links elongate through wear and the sprocket teeth become rounded. A worn chain produces vibration and shudder felt through the driveline in 4WD, and in advanced cases the chain can skip over the sprockets, causing intermittent loss of drive to either axle. The failure is accelerated by off-road use that demands sustained 4WD engagement.

• Vibration or shudder felt through the floor and transmission tunnel when in 4WD
• Hesitation or difficulty engaging or disengaging 4WD modes
• Metallic particles visible in transfer case oil when drained

Drain and inspect the transfer case oil for a metallic sheen or fine metal particles, which indicate chain and sprocket wear. On a test drive in 4WD on a safe road, check for vibration or shudder through the floor and driveshaft area. Attempt to engage and disengage 4H and 4L multiple times and confirm positive, clunk-free engagement. Ask for the transfer case oil change history — fluid that has never been changed dramatically accelerates internal wear.

Parts involved: Transfer case.

$1,100 to $2,800 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.

• “Has the transfer case oil ever been changed, and if so, when?”
• “Is there any vibration or shudder when driving in 4WD?”
• “Does 4WD engage cleanly and hold without slipping or grinding?”

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.