Adjustable coilover front suspension has been used for many years in motorsport and on the offroad scene was developed more for the desert racing scene that has in turn given birth to the stadium trucks that compete in a series with the V8 Supercar events here in Australia.
These shocks feature a threaded body shock absorber and either come with an adjustable spring seat or a top compression ring at the top of the spring. Either design achieves the same thing and that is to allow adjusting the preload on the coil spring to alter the ride height.
For many people the thought of adjusting the front ride height has appeal as it allows them to level their truck out as from the factory, the rear is often higher than the front to allow for heavy loads. In practice, from our experience, unless you are setting up a race truck, these become a set and forget adjustment.
Some coilovers come with an external reservoir. Once again, this is borrowed from motorsport as it allows an external piston and greater oil volume for extreme conditions.
Few recreational drivers in Australia drive in conditions that require this feature and installation becomes more problematic as it can be hard to find room to mount the external reservoir in many modern vehicles.
It generally makes more sense to go with an internal floating piston (IFP) design that gives the benefit of a coilover design without the external reservoir.
Most of these shocks are rebuildable although some require special tooling from the shock manufacturer that few workshops have.
Also because of their motorsport origins, most quality coilovers can be revalved to change their damping characteristics.
With some coilover shocks, there is insufficient clearance between the coil spring and the sway bar. This can be resolved by installing a Sway bar relocating bracket that moves the swaybar forwards. However, this is also a compromise and causes clearance issues in front of the swaybar and the radiator support brackets.
Most people deal with this by spacing the support brackets down at the expense of ground clearance. VMN’s approach to this problem is to fit a high clearance bash plate that also makes room for the swaybar and incorporates recovery points.
VMN also offers some Bilstein front shocks with adjustable spring seats that give a range of adjustability and the ability to set the shocks at a higher lift height than what can be achieved with a normal fixed height spring seat.