Terrain Tamer offers Gross Vehicle Mass (GVM) upgrade kits with parabolic leaf springs for Ford Ranger, Toyota Hilux, Land Cruiser and many other 4WD models.
The GVM is a rating set by the original manufacturer and refers to the legal maximum weight of the vehicle. This rating incorporates the wheels and the vehicle itself, as well as everything sitting atop. Built into the GVM is also the imparted tow ball mass when towing, and rated axle capacity, a limit set for how much weight should be distributed to each axle.
Adding anywhere from 180kg to 480kg to the original GVM, depending on the vehicle, the Terrain Tamer Parabolic GVM upgrade kits include Terrain Tamer Parabolic Springs and all required suspension components, including Smart Coils, (where applicable) to provide a safe and comfortable upgrade solution, with more flex, less shock and exceptional load carrying ability for vehicles that are pushed to their GVM and axle loading limits when towing or heavily loaded.
Terrain Tamer’s Parabolic Springs contain fewer leaves than regular leaf springs and get their name from their tapered ‘parabolic’ design, meaning the spring is thicker in the centre and thinner toward the ends, rather than the usual linear style. This design directly addresses some GVM issues by eliminating the weight of often heavy, thick, traditional leaf packs and dramatically reducing the unsprung weight of the vehicle, essentially freeing up the weight needed for practical use.
This not only makes them both safer on the road, but also acts to create a more comfortable ride when the vehicle is unloaded, addressing the varying and ever-changing applications that the modern day 4WD is used for and ensuring it is comfortable whether empty or loaded.
The parabolic design also helps the spring to flex while still providing the strength needed to bear the weight of heavy loads. Particularly useful in 4WD applications that carry excessive load on the driveline, or when challenged with difficult terrain, the flex afforded with a parabolic spring allows the spring to give a little when the driver hits a bump in the road, allowing the differential housing to rotate with the springs and effectively providing a smoother ride, reducing the shock transferred to the crown wheel and pinion, stopping the wheel from spinning and maintaining safety and drive. The same force with a standard leaf pack would almost certainly cause more shock to the vehicle and driver.
As well as these advantages, extensive research and development shows that the new shape provides better axle articulation and almost no interleaf friction, allowing the spring to compress or extend with ease without touching each other until there is a reasonable load on the vehicle. This means that the springs are not only quieter, but it also helps minimise any issues with rust build-up, which can be a major cause of failure in standard leaf springs.
As with all GVM upgrade kits, Terrain Tamer’s Parabolic GVM kits have been thoroughly tested and analysed by Multidrive Technology to reach Secondary Stage Manufacturers’ approval and can be installed either prior to registration or on existing registered vehicles at approved workshops.
For more information, visit terraintamer.com/suspension.
