Leaf Springs for Dump Trucks, Haul Trucks, and Heavy Equipment

What Leaf Springs Do on Heavy Equipment and Why Failure Is Costly

Heavy equipment leaf springs are not a passive component. On a rigid dump truck under full payload, the spring pack is in constant dynamic compression, absorbing impact forces that can momentarily exceed the machine's unladen weight in a single jolt across a haul road discontinuity. Each blade in the pack contributes to the assembly's composite spring rate, determining how the axle responds to load and how much impact energy is absorbed before it reaches the chassis frame.

When a blade cracks or the pack loses structural integrity, the remaining blades carry a disproportionate load share. Spring rate drops, the axle begins to articulate outside its design range, and tyre wear accelerates on the affected side. Left in service, a degraded dump truck leaf spring will eventually allow the axle to bottom out under full payload,d transmitting unattenuated force directly into the chassis, the differential housing, and every suspension mounting point connected to that axle.

Leaf spring condition also has a direct bearing on the wider suspension and steering parts system. Worn packs place additional stress on suspension bushings, alter the alignment geometry that wheel hubs depend on, and reduce the effectiveness of damping components in combined spring and damper suspension configurations. The cost of a replacement leaf spring pack is a fraction of the structural repairs that a failed spring can trigger across the surrounding system.

Leaf Spring Configurations We Supply

We stock both multi-leaf and parabolic configurations, matched precisely to the OEM specification of each supported machine platform.

Multi-Leaf Spring Packs

Multi-leaf spring packs are the standard configuration on the majority of rigid and articulated dump trucks operating in construction and mining environments. The assembly is made up of multiple graduated steel blades stacked and clamped together, with each blade contributing a portion of the overall spring rate. The redundancy built into a multi-leaf spring pack for heavy equipment means a single blade failure does not cause immediate total suspension loss — but it does signal that the remaining blades are now overloaded and that a full pack replacement should be scheduled before the next loaded production shift.

We supply multi-leaf spring pack assemblies for Cat, Komatsu, Bell, and Volvo dump truck platforms, available as complete packs or as individual replacement blades where the rest of the pack remains within serviceable condition.

Parabolic Leaf Springs

Parabolic leaf springs use fewer, thicker blades tapered to a variable cross-section, widest at the centre, and reducing progressively toward each end, distributing bending stress more evenly along the blade length than a conventional multi-blade stack. The result is reduced inter-blade friction, a more progressive load deflection curve, and a longer maintenance interval under equivalent operating loads. Where an OEM specification calls for a parabolic leaf spring for heavy equipment, we stock the correct configuration rather than substituting a conventional multi-leaf pack of equivalent rated capacity.

Machine Platforms and Models We Cover

Our heavy equipment leaf spring inventory is catalogued to the following platforms and model lines:

Caterpillar (Cat)

• Cat 773 leaf spring — rigid dump truck rear suspension assembly
• Cat 775 leaf spring — rigid dump truck rear suspension assembly
• Caterpillar haul truck spring assemblies across the Cat 770-series platform

Komatsu

• Komatsu 730E leaf spring — rigid haul truck platform
• Komatsu dump truck leaf spring range across the HD-series model lineup

Bell

• Bell dump truck leaf spring assemblies — including the Bell B30 platform and Bell B-series range
• Bell articulated dump truck leaf spring packs for front and rear axle positions.

Volvo

• Volvo dump truck leaf spring assemblies for the A-series articulated dump truck range
• Volvo dump truck rear suspension spring packs

If your specific model is not listed above, contact our team with the machine serial number,r and we will confirm the correct specification before any order is placed.

Five Signs Your Leaf Springs Need Replacing

Leaf spring failure on heavy mining and construction equipment rarely happens without warning. These are the most reliable field indicators that a dump truck leaf spring or haul truck leaf spring requires immediate inspection and likely replacement:

1. Visible blade cracking or separation — any fracture line across a blade face, or a visible gap that has opened between blades in the pack, means the assembly is already beyond serviceable condition and should not complete another loaded shift without replacement.
2. Uneven tyre wear across one axle — accelerated wear concentrated on one side of a rear axle indicates the heavy equipment leaf spring on that side has lost load capacity, allowing the axle to run out of its correct alignment plane.
3. Chassis sitting lower on one side when unladen — when the machine is parked, empty, and one side of the rear sits measurably lower than the other, the spring pack on the low side has deflected below its rated static load height.
4. Bottoming out under full payload — a pack that has lost spring rate will allow the axle to contact the bump stop at a lower-than-design payload threshold, transmitting full impact force directly into the chassis and mounting hardware.
5. Creaking or knocking from the spring mounting area — noise from the spring eye or centre bolt location during machine articulation can indicate blade cracking, centre bolt shear, or worn spring eye bushings requiring immediate inspection.

Any combination of the above symptoms should be treated as a priority maintenance item before the machine returns to loaded production operation.

OEM vs Aftermarket Leaf Springs: Which Is Right for Your Application

The choice between OEM and aftermarket on heavy-duty leaf springs comes down to two variables: the manufacturing specification of the aftermarket option and the specific operating context of the machine.

OEM leaf spring assemblies are produced to the original design drawing, with the exact blade geometry, steel specification, and rated load capacity defined by the machine manufacturer. For equipment operating under an active OEM warranty, or for platforms where spring geometry is closely toleranced to specific OEM mounting hardware, genuine OEM parts remain the most appropriate choice, and we can source them.

Quality aftermarket leaf spring assemblies for heavy equipment, manufactured to OEM-equivalent steel grade and load rating, are a standard and widely accepted procurement practice across the global mining and construction industries. The determining factor is whether the aftermarket spring meets the OEM-defined load deflection curve and fatigue cycle requirements, not whether it carries an OEM label. We only supply aftermarket leaf springs where this specification can be confirmed and validated.

For the majority of Cat, Komatsu, Bell, and Volvo dump truck applications, a quality aftermarket leaf spring pack delivers equivalent service life at a lower procurement cost than the genuine OEM equivalent.