How to choose the correct springs for your application.
Author: Jack Date Posted:2 May 2017
We often hear people saying "My mate told me to fit HD coils" or "I need 500kg leaf springs because I load up heavy for the Christmas holiday" but in most cases, it simply isn't true. Choosing the correct components is the difference between a harsh uncomfortable ride or a vehicle you will never want to get out of!
Below are some simple tips on how to set up your vehicle correctly, to maximise not only the ride comfort but the life of your suspension components.
1. Front Spring Weight Rating
Setting up the front end of your 4WD can literally make or break your suspension setup. The key to choosing your front coil springs is simple, select the option that suits your vehicle currently. If you have a factory plastic bumper, select the plastic bumper coils. If you select a HD coil (for e.g. bar and winch) and do not have a bar and winch, you will not only have a harsh ride, you will damage your shocks.
2. Constant Load
Simply put, your 'constant load' rating is how much weight you always have in there. Generally for leaf sprung vehicles we offer 3 different ratings, a 0-150kg or 0-300kg rating, a constant 300kg and a constant 500kg rating. These figures relate to what you always have on the vehicle, not occasional weight or weight that comes on and off the vehicle.
0-150kg or 0-300kg rating
These leaf springs are suited to most drivers and will handle roughly the same load as your factory leaf springs. They are designed to give the best ride comfort, as well as handle occasional loads in the back. If you drive around empty or with a light load (such as a fridge), and every weekend or two you put some camping gear in the back and/or tow a trailer these are the leafs for you. These leafs are also suitable for drivers that have a constant weight of around 100kg in the back, for e.g. a fridge & rear mounted dual battery.
These leaf springs are suited to drivers that always have around 300kg in the back, this could be made up of tools & toolboxes, drawers, a canopy, a large water tank or heaps of other things.
These leaf springs are suited to drivers that always have 500kg-GVM in the back. This includes the items listed above, but could also be a heavy steel workbody or other bulky items. We find most tradie vehicles that are always loaded up with lots of tools and supplies require these leaf springs, but you should always work out your constant load and find an applicable leaf for your situation.
Constantly varying loads
Some days you have an empty tub, other days you are at GVM & towing a heavy load? Unfortunately with coil & leaf springs, generally you can't have your cake and eat it too. A light load leaf will settle down when loaded up, and a constant load leaf will ride extremely firm, and sit very high (causing shock damage) when empty.
For vehicles that have constantly varying loads, we recommend pairing up a pair of light load leafs with an airbag kit, which will distribute the load correctly and will ensure that no matter if you are empty or at GVM, you will always have a comfortable ride.