Nissan Patrol: Rear Leaf Spring Sag and U-Bolt Fatigue

Both Y60 and Y61 Patrols use a rear multi-leaf spring suspension that progressively sags under load over time, particularly on vehicles used for towing or carrying heavy loads. The U-bolts clamping the spring pack to the axle housing fatigue and crack, and on high-mileage examples can fracture, allowing the axle to shift laterally under braking. Spring interleaf corrosion in wet climates causes the leaves to fuse and crack rather than flex, resulting in sudden spring pack separation. A sagged rear causes the vehicle to sit nose-high, adversely affecting headlight aim and handling.

• Rear of vehicle sitting noticeably lower than the front when unladen
• Bottoming out on moderate bumps at legal load
• Clunking from the rear axle area when transitioning from acceleration to braking
• Visible rust between spring leaves on inspection from beneath

Measure the rear ride height from the axle housing to the chassis rail on both sides and compare to the front — more than 30 mm lower at the rear than factory spec indicates sag. Inspect the U-bolts for cracks at the bend radius and for elongated holes in the spring plate. Bounce the rear of the vehicle and listen for a clunk — movement of the axle on a fatigued U-bolt produces a characteristic double knock. If a workshop inspection is possible: With the vehicle on a hoist, inspect between each spring leaf for cracking and interlayer rust.

Parts involved: Rear leaf spring.

$500 to $2,500 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 vehicle been used for regular heavy towing or payload, and at what weights?”
• “Have the rear springs or U-bolts ever been replaced?”

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.