The venerable leaf spring became prevalent way back in the 1750’s on horse drawn carriages leaf spring as we know it today is generally connected at the front of it via a pin to the chassis of the vehicle and the rear of the leaf spring is attached to the chassis via a swinging shackle. This shackle allows the leaf spring to elongate when compressed and that then makes for a softer ride. Leaf springs are generally attached to the vehicle’s rear axle via u-bolts.
It is important that these u-bolts are replaced every time the springs or the axle are removed as the threads can stretch and come loose if reused. Then there is a risk that the axle will part company with your vehicle which is something that most of us would rather not experience.VMN offers a range of leaf springs that are match to suit different load-carrying conditions.
For each vehicle, usually we have a light duty spring which is suited for standard weights of between 100 and 300 kg, a medium weight spring that is good for between 300 and 500 kilos and a heavy weight spring suited for loads that exceed 500 kg on the rear axle. Where possible we recommend that shock absorbers are also matched to suit the loads that you carry.
However, few manufacturers offer different valving options for different weights and conditions.
Leaf springs for four-wheel drive conditions generally require a greasable pin to hold the front of the spring to the chassis and also greasable shackles often when replacing rear leaf springs, the existing pin needs to be cut off to remove it from the vehicle because fuel tanks and other components prevent it from being easily removed.
We also recommend that the various suspension bushes that are fitted between attachment points and the actual Spring and Chassis are placed while it is apart. The most highly regarded leaf spring manufacturer in Australia we believe is Carrols Suspension Solutions in Brisbane.
Their suspension brand is EFS and they manufacture many leaf springs for other brands that white label the EFS product. VMN is a distributor of EFS products and are happy to advise you on which is the correct spring for your application.
Many mini off road vehicles in Australia come with Leaf Springs from the factory because most of the four-wheel drive utes in our market are manufactured in Thailand which has significant tax breaks for vehicle manufacturers that use leaf springs and drum brakes.
One notable exception is the Nissan NP 300 Navara which comes with coil springs because it is not manufactured in Thailand. Nissan have been using coil springs in their Nissan Patrol four-wheel drive ute for many years.