| 1 | Multi-Leaf Semi-Elliptic Spring | A stack of tapered or constant-thickness leaves secured around a central bolt. It carries vertical load while locating the axle and controlling wheel movement. | Light commercial vehicles, utility trailers, vans, pickups, and heavy-duty road vehicles. | Match the spring orientation, center-bolt position, eye diameter, eye-to-eye length, and installed arch. Tighten U-bolts to the vehicle maker’s specification with the vehicle at the specified ride height. | Inspect for broken leaves, shifted center bolts, worn bushes, loose U-bolts, corrosion, and abnormal contact marks. Do not lubricate composite or friction-sensitive surfaces unless approved by the vehicle maker. | Check leaf thickness, free camber, eye alignment, surface cracks, edge damage, corrosion pits, bush fit, and correct left/right configuration. | Replace as a matched axle set Replace immediately after a fracture, severe corrosion loss, permanent sag, or repeated overload damage. |
| 2 | Parabolic Leaf Spring | Leaves are tapered in thickness and normally have limited contact between adjacent leaves. The design reduces inter-leaf friction and can improve ride response. | Light commercial vehicles, buses, off-road vehicles, and selected trailer suspension systems. | Install with the correct tapered orientation and center bolt. Confirm that retaining clips and pads do not restrict normal flexing. Avoid mixing parabolic and conventional leaves in one pack unless specifically engineered. | Keep contact surfaces clean and inspect for surface scoring, cracks, damaged pads, loose clips, worn bushes, and uneven ride height. | Verify the taper profile, camber, eye dimensions, center-bolt location, material finish, and absence of forging or heat-treatment cracks. | Use the same design on both sides Plan replacement when camber is permanently reduced, a leaf is cracked, or ride height differs significantly from the opposite side. |
| 3 | Mono-Leaf Spring | A single, relatively wide leaf provides the main spring function. It is designed as a complete spring rather than as one component of a multi-leaf pack. | Light-duty vehicles, compact trailers, and applications where low mass and simple packaging are important. | Confirm the spring’s load rating and mounting geometry. Install the correct isolators, bushes, center bolt, and U-bolts. Avoid clamping or drilling the leaf unless the design specifically allows it. | Inspect the full leaf surface for cracks, edge chips, corrosion, and permanent set. Check bush movement and fastener torque during scheduled service. | Measure free camber, width, thickness, eye dimensions, and surface hardness where required by the inspection plan. | Replace the complete spring A damaged mono-leaf should not be repaired by adding an unapproved leaf or by welding. |
| 4 | Helper or Overload Spring | An auxiliary leaf engages progressively under increased load. It supports the main spring but does not automatically increase the vehicle’s legal gross weight. | Commercial vehicles, pickups, delivery vehicles, and trailers with variable payloads. | Set the designed gap or contact condition between the helper and main spring. Confirm adequate clearance from the axle, frame, brake lines, and tires throughout suspension travel. | Inspect contact surfaces, mounting clamps, brackets, spring seats, and evidence of harsh engagement. Check for overloading and uneven payload distribution. | Verify thickness, length, camber, end shape, bracket compatibility, and correct engagement clearance according to the suspension design. | Replace with the complete approved set Do not use a helper spring to compensate for a sagging or broken primary spring. |
| 5 | Slipper-End Leaf Spring | One end uses an open or slipper-style termination that slides in a hanger or bracket instead of using a conventional circular eye. | Heavy-duty trailers, agricultural equipment, and selected commercial vehicle suspensions. | Position the slipper end in the correct hanger orientation and verify free sliding movement. Inspect hanger wear before installation and use the specified clearance and lubrication method. | Check the slipper contact area, hanger plate thickness, wear grooves, cracks, corrosion, and side-to-side alignment. | Measure slipper width, end radius, spring length, camber, leaf thickness, and compatibility with the hanger and equalizer. | Inspect hanger and equalizer together Replace the spring when the slipper end is cracked, excessively worn, or permanently deformed. |
| 6 | Full-Elliptic Leaf Spring | Two semi-elliptic springs are arranged to form an approximately complete ellipse. The layout provides suspension movement but usually requires separate axle-location control. | Historic vehicles, specialty equipment, and selected non-standard suspension systems. | Confirm the spring’s mounting geometry and the separate axle-location system. Check that the full range of movement does not cause interference with the frame or steering components. | Inspect both spring halves, shackles, brackets, retaining hardware, and axle-location members for wear, distortion, and cracks. | Check symmetry, free camber, eye alignment, leaf thickness, mounting-hole condition, and surface defects. | Replace paired components together Replacement requires a complete geometry check because worn locating members can cause rapid spring damage. |
| 7 | Three-Quarter-Elliptic Spring | A semi-elliptic spring is combined with an additional quarter-elliptic section. The arrangement is uncommon in modern mass-production vehicles. | Special-purpose, historic, and custom mechanical suspension designs. | Follow the original mounting sequence and preserve the intended pivot and load paths. Verify that the spring is not installed upside down or with reversed eye orientation. | Inspect pivot pins, brackets, leaves, fasteners, and contact areas for fatigue, wear, looseness, and corrosion. | Compare both sides for geometry, camber, length, thickness, eye alignment, and material condition; use drawings or measured original parts where available. | Plan as a custom replacement Confirm dimensions and load requirements before ordering because direct interchangeability is limited. |
| 8 | Quarter-Elliptic Spring | A short leaf spring is fixed at one end and supports the suspension at the other. It functions as a cantilever-type spring. | Historic vehicles, lightweight equipment, and specialized suspension layouts. | Secure the fixed end with the correct clamp or fasteners and confirm that the free end has sufficient travel clearance. Check the mounting structure for fatigue. | Inspect the fixed mounting area, free end, brackets, pivot surfaces, and nearby frame members for cracks and deformation. | Verify length, taper, thickness, mounting-hole location, camber, and crack-free edges. Dimensional accuracy is especially important for cantilever designs. | Replace before fatigue failure Replace when permanent deflection, edge cracking, or mounting-hole elongation is observed. |
| 9 | Transverse Semi-Elliptic Spring | A semi-elliptic spring is mounted across the vehicle rather than along its length. It can support both sides of an axle or wheel assembly depending on the design. | Historic vehicles, selected independent suspensions, and specialized low-volume applications. | Center the spring accurately and confirm equal left/right ride height. Check pivot security and ensure steering, brake, and tire clearances throughout travel. | Inspect the center mount, outer eyes, shackles, bushes, brackets, and signs of asymmetric loading or lateral movement. | Check centerline position, camber symmetry, eye alignment, thickness, surface finish, and mounting-hole dimensions. | Replace after geometry comparison Unequal camber or ride height can indicate fatigue, incorrect installation, or a damaged mounting structure. |
| 10 | Platform or Cantilever Leaf Spring | A leaf spring is arranged to support a platform or body structure, often with one end fixed and another connected through a pivot or link. | Specialized trailers, industrial equipment, historic vehicles, and custom load-support systems. | Install according to the designed load path. Check pivot alignment, mounting rigidity, travel stops, and clearance from the supported platform and frame. | Inspect fixed mounts, pivot pins, bushes, brackets, spring edges, and contact zones for fatigue and fretting wear. | Verify spring rate requirements, free camber, thickness, width, mounting geometry, surface condition, and correct heat-treatment documentation. | Replace with design verification Recalculate load distribution if the platform, payload, mounting points, or operating conditions have changed. |