Armoured Vehicle
Suspension Glossary

A classification system (per VPAM/EN 1522) indicating the level of ballistic threat a vehicle's armour can defeat. B4 stops handgun rounds (.44 Magnum, 9mm); B6 stops rifle fire (7.62x51mm NATO); B7 defeats armour-piercing rounds (7.62x63mm AP). Higher levels require thicker armour and correspondingly heavier suspension upgrades.

The lateral tilting of a vehicle's body during cornering, caused by the transfer of weight to the outer wheels. Armoured vehicles experience significantly increased body roll due to the higher centre of gravity from added armour mass. Heavy-duty sway bars are engineered to resist this roll and maintain vehicle stability during evasive manoeuvres.

The progressive loss of shock absorber performance that occurs when hydraulic fluid overheats and aerates (forms gas bubbles), reducing the fluid's effective viscosity and damping force. Fade is accelerated under heavy armour loads and sustained use. Foam Cell technology prevents fade by separating oil and gas phases.

A shock absorber design that uses a micro-cellular foam insert to separate the hydraulic fluid from the nitrogen gas charge. This prevents oil aeration (cavitation) under sustained high-load cycling, eliminating damping fade. Tough Dog Armoured uses Foam Cell technology in its 50mm bore shock absorbers and 35mm steering dampers for sustained performance under armour loads of 1,500-3,000kg.

The maximum legal weight a vehicle can safely carry, including the vehicle itself, passengers, fuel, cargo, and any armour or modifications. Armoured vehicles almost always exceed factory GVM due to added ballistic protection (400-800kg), requiring an engineered GVM upgrade to remain legally compliant and safe to operate.

A suspension system where each front wheel moves independently, using coil springs rather than a solid axle with leaf springs. IFS platforms (e.g. newer Land Cruisers, Rangers) require X5K coil springs engineered for armoured loads rather than the leaf spring upgrades used on solid-axle vehicles like the LC70.

A Toyota 4WD platform widely used as the base for armoured military, security, and government vehicles globally. The LC70's solid front and rear axles, robust chassis, and proven reliability make it the world's most armoured 4WD platform. Suspension upgrades typically use leaf springs and 50mm bore shock absorbers.

A shock absorber design using a single tube containing the piston and a high-pressure gas charge separated by a floating piston. Monotube designs offer advantages in single-impact high-performance scenarios but can be more susceptible to fade under sustained heavy loads compared to Foam Cell (emulsion) designs in armoured vehicle applications.

The National Institute of Justice (US) body armour standard, sometimes referenced for vehicle armour. NIJ Level III and IV are roughly comparable to VPAM B6 and B7 respectively. While primarily a personal armour standard, it is frequently referenced in armoured vehicle specifications for international procurement.

A leaf spring design where the spring rate increases as the load increases, achieved through variable leaf thickness or multi-stage leaf pack geometry. This provides a softer ride when the vehicle is lightly loaded and firmer control under heavy armour loads. Tough Dog Armoured uses SUP9/SUP9A steel in progressive rate configurations for armoured vehicle applications.

A tyre designed to continue operating after losing air pressure, typically via reinforced sidewalls or an internal support ring. Run-flat systems add significant unsprung weight and increase steering feedback stiffness, necessitating a heavy-duty steering damper upgrade to maintain vehicle control in both normal and deflated operational states.

A surface treatment process where small spherical media are blasted at a spring's surface under controlled conditions, inducing compressive residual stress. This significantly extends fatigue life by preventing crack initiation. All Tough Dog Armoured leaf springs are shot-peened as standard for extended service under armour loads.

A NATO standardisation agreement defining protection levels for armoured vehicles against kinetic energy, artillery, and mine blast threats. Levels range from Level I (light) to Level VI (heavy). STANAG 4569 is the primary reference for military vehicle procurement and influences suspension design requirements for blast-resistant vehicles.

A hydraulic cylinder mounted between the chassis and steering linkage that absorbs steering kickback and vibration. Essential on armoured vehicles where run-flat tyres, heavy wheels, and armour mass amplify steering feedback. Tough Dog Armoured's 35mm EXT Foam Cell steering damper restores OEM steering feel under armoured load conditions.

High-tensile silicon-manganese alloy spring steels used in heavy-duty leaf spring manufacturing. SUP9A is a modified version with improved hardenability. These steels are shot-peened and pre-stressed to maximise fatigue life under the sustained heavy loads typical of armoured vehicle applications.

A torsional spring connecting the left and right sides of a suspension system, designed to resist body roll during cornering. Armoured vehicles require upgraded heavy-duty sway bars with increased diameter and high-strength spring steel to manage the additional lateral forces generated by 400-800kg of added armour mass.

The portion of a vehicle's mass not supported by the suspension system — wheels, tyres, brakes, and some suspension components. Run-flat tyres and ballistic wheel upgrades increase unsprung weight, which affects ride quality, steering feedback, and suspension component wear rates in armoured vehicles.

A European ballistic protection standard (Vereinigung der Prüfstellen für angriffshemmende Materialien und Konstruktionen) that defines threat levels for armoured vehicles. It provides a standardised testing methodology for ballistic resistance and is widely used in international armoured vehicle procurement alongside STANAG 4569.

A proprietary Tough Dog coil spring manufactured from X5K spring steel, hot-formed and heat-treated for armoured vehicle independent front suspension (IFS) platforms. The X5K designation indicates a specific tensile strength and heat treatment process engineered to maintain ride height and handling under sustained armour loads.