Leaf Springs

Nolathane leaf spring parts keep a leaf spring suspension working the way it was designed to. A leaf spring is more than a stack of steel. It relies on pins, shackles, bushes and U-bolts to attach it to the chassis and axle, and every one of those parts wears over time. When they do, even a healthy spring can?t hold the axle in place, and the vehicle starts to squeak, wander and feel unsettled under load.

The range covers the leaf spring parts that see the most wear on 4WDs, utes, vans and trailers, helping restore quiet, stable and predictable rear suspension for work, touring and towing.

Parts of a Leaf Spring

Understanding the parts of a leaf spring makes it easier to diagnose problems and choose the right replacement parts:

• Main leaf is the longest leaf, with an eye rolled into each end
• Spring eyes hold the bushes that the spring pivots on
• Additional leaves sit under the main leaf and add load capacity
• Centre bolt holds the leaves together and locates the spring on the axle
• Rebound clips stop the leaves fanning apart when the axle drops
• Fixed pin passes through the front eye and attaches it to the chassis hanger
• Shackle connects the rear eye to the chassis and swings as the spring flexes
• U-bolts clamp the spring pack to the axle through a saddle or plate

The spring leaves themselves rarely need replacing until they sag or crack. The pins, shackles, bushes and U-bolts usually wear out first.

How Leaf Spring Hardware Works Together

When a loaded vehicle hits a bump, the spring flattens and gets longer. The front eye pivots on the fixed pin, while the shackle swings rearward to let the spring lengthen. The U-bolts keep the axle clamped firmly to the centre of the spring the whole time.

Because the leaf spring also locates the axle, any slack in these parts lets the axle move. Worn bushes or pins allow the axle to shift fore and aft under braking and acceleration, and the rear wheels can steer slightly as the body rolls. That?s why fresh leaf spring parts make such a difference to stability, especially when towing or carrying heavy loads.

Benefits of Quality Leaf Spring Parts

• Firm axle location, reducing rear-end wander and passive steer
• Better stability under braking, when towing and when carrying loads
• A quieter rear end, free of squeaks, creaks and clunks
• Longer life for the springs, mounting points and tyres
• Smoother spring movement for better ride quality
• Easier future servicing with greasable pins and shackles

When to Replace Leaf Spring Parts

Signs that leaf spring parts need attention include:

• Squeaking or creaking from the rear over bumps
• Clunking when taking off, braking or crossing speed humps
• The rear of the vehicle wandering, especially with a load or trailer
• Rust, cracks or distortion on pins, shackles or U-bolts
• Pins that are seized and won?t turn
• Cracked, flattened or extruded bushes at the spring eyes or shackles
• The axle sitting off-centre on the spring, or uneven rear tyre wear

If the vehicle sits low at the rear, bottoms out easily or one side sits lower than the other, the spring itself may have sagged or a leaf may be cracked. Replacing worn hardware won?t fix a tired spring, so check both.

Replacing Both Sides

Leaf spring parts should be replaced in pairs across the axle. New pins, shackles and bushes on one side and worn parts on the other leave the axle located unevenly, which can make the vehicle pull under braking and wear tyres unevenly. If the springs themselves are being replaced, fit new hardware and U-bolts at the same time, as old U-bolts shouldn?t be reused once they?ve been tightened.

Greasable Pins, Shackles and Protection

Factory pins usually can?t be lubricated, so water, dust and grit grind the bushes and seize the pins. Greasable pins and shackles allow fresh grease to be pumped through the joint, flushing out contaminants and keeping the spring pivoting smoothly. Protective caps over greasable fittings help keep mud and grit out of the grease points between services.

These upgrades suit 4WDs and utes that see beaches, river crossings, dusty roads and corrugations, where factory hardware wears fastest.

Polyurethane Spring Bushes

Nolathane has been making polyurethane suspension bushings since 1974, originally developed to replace brass bushes in hillclimb competition. The signature red bushings are made in a range of durometers (hardness grades) for each position, are mechanically fitted with minimal crush, and offer outstanding abrasion resistance, high load-bearing capability and resistance to oil, grease, ozone and weathering. Paired with greasable pins and shackles, they keep the spring eyes firm and quiet for longer.

The honest trade-off is that polyurethane spring bushes need regular greasing to stay quiet, particularly on vehicles that see water and dust.

Leaf Springs on Trailers

Many trailers, boat trailers and caravans also use leaf springs, and their U-bolts and hardware suffer from salt water, sitting idle and rough roads. Replacing rusted U-bolts and hardware on a trailer improves safety and stability on the road. Check that each part suits the trailer?s spring width, axle size and load rating.

Fitting and Maintenance

Fitting leaf spring parts suits professional workshops and experienced home mechanics. Support the chassis securely, support the axle to unload the springs, and work on one side at a time so the axle stays located. Tighten pins, shackles and U-bolts with the vehicle at ride height, and tighten U-bolts evenly in a crossing pattern to specification.

After fitting, re-check U-bolt and shackle torque after the first few hundred kilometres, and grease any greasable fittings at every service and after water or beach driving. Have a wheel alignment (tracking) checked if the axle position changed.

Choosing the Right Parts

Confirm the vehicle, drivetrain and model year, as spring eye sizes and hardware differ between variants. For U-bolts, measure the axle tube diameter, the required length and the thread size. Each listing shows the vehicles or dimensions the part suits. Our fitment guarantee means the parts you order for your vehicle are confirmed to suit it.

Shop Leaf Springs

Sagging leaf packs are one of the repairs covered in Nolathane's suspension springs range.

Find the leaf spring parts for your vehicle, then order online with fast shipping or have them fitted by a Nolathane reseller. Every product is backed by Nolathane?s warranty, 60-day returns give you time if a part isn?t right, and our local support team can help whether you?re repairing a squeaky rear end, servicing a working ute or preparing a 4WD for touring.