GON2FAR Suspension Systems

Introduction

In the beginning there was the humble leaf spring, bastion of many four-wheel drive suspension systems on utility vehicles the world over. Simple in design and easy to maintain and fix, leaf springs are still fitted to vehicles even today.

However, those who have driven older Series Land Rovers will know that a combination of rust, wear and limited articulation all conspire to give Leaf Sprung vehicles a reputation for combining a hard ride with a capacity for getting cross axled.

Then the Parabolic ‘leaf’ spring came along and its advanced design and differing materials gave leaf sprung vehicles a new lease of life, even challenging coil sprung suspensions for comfort, with much improved articulation, especially compared to tired and rusty traditional leaf springs.

Back in early 2000, Nigel Aldred, like many like minded enthusiasts before him, decided it was time to rebuild his beloved 109 Leaf Sprung Land Rover and soon discovered for himself the advantages of Parabolic springs. Some ‘before and after’ off road testing soon confirmed Nigel’s suspicions that increased articulation enabled better control and less crossed axles over rough terrain.

Most of us would have been happy to leave it there but luckily for us Nigel began to formulate plans for taking his 109’s parabolic suspension system to new limits. What followed was many long months of development, trials and experiments that eventually led Nigel to develop some simply amazing modifications to that old 109, and in so doing form GON2FAR Suspension Ltd in order to help others achieve similar results.

Just take a look at these shots and you’ll begin to appreciate what Nigel has managed to achieve, remember that you are looking at vehicles fitted with leaf springs!

First the 109, which has been fitted with the GON2FAR front-end kit and has (so far) unmodified Parabolic spring rear suspension.

Then the 88, which is fitted with a suspension system based on Revolver Shackles front and rear.

Front axle and the GON2FAR Suspension System

Nigel soon discovered that first and foremost it was the front suspension that was the primary limiting factor in the axle articulation of his Parabolic fitted 109. In fact, when fitted with parabolics alone the rear axle gave twice as much travel as the front, giving an ‘unbalanced’ overall system. There was clearly a need to redress this balance problem since the more equally balanced articulation is between the front and rear axles the more level and stable the vehicle will be as it crosses uneven terrain. Initial research and development then, focussed on this limiting front axle.

Nigel’s work identified the key factors critical to the success of his new system.

The GON2FAR Spring Mount

At the heart and soul of the GON2FAR system is the unique front spring mount that pivots to absorb twist in the parabolic spring. Development of this critical component was the key to the whole GON2FAR system since it ‘frees’ the parabolic spring of the limitations imposed by its own bushes and those in the vehicle chassis.

On a standard system, as one end of the axle drops away from the vehicle the angle between the axle and chassis can become quite severe. When no more angle can be absorbed by the give in the bushes the spring itself must twist to allow more movement. A leaf spring is pretty resistant to this twisting action and this adds up to a resistance to articulation. Arranging the spring mount to pivot prevents the build up of twist in the spring, allowing the spring and axle to move more freely.

But, whilst its all very well to have a suspension system that lets the wheels hug the ground over improbable obstacles, that same system also has to enable the vehicle to drive along at much higher speeds, especially when cornering. The GON2FAR spring mount then features a manual locking mechanism that unleashes its full potential off road but which restores near normal behaviour when driven at higher speeds.

A word of warning here, a vehicle fitted with any suspension modifications, whether supplied by GON2FAR Suspension Ltd or nor, will exhibit handling characteristics different from those of a standard vehicle. It is the driver's responsibility to familiarize him/herself with these characteristics and to ensure that at all times the vehicle is driven safely.

Long travel, increased working angle prop shaft.

As the axle articulates, it stretches and compresses the sliding joint in the prop shaft. It also increases the angle at which the Universal joints have to operate. As you can guess, the standard Leaf sprung Land Rover prop shaft was not designed to cope with the demands of dramatically increased suspension travel of GON2FAR and so again, Nigel went back to the drawing board and with the help of a specialist engineering company, developed a customised prop shaft with an extremely long travel spline and high angle yokes. In fact this stage of development had useful spin offs for anyone considering building a Hybrid or perhaps just engine, gearbox or suspension conversions since Nigel’s business is now able to offer a stand-alone, custom prop shaft service to anyone that needs it. (See the GON2FAR website for details)

Long Travel Shock absorbers

Shock absorbers are another limiting factor in improving suspension travel. Not only does their maximum allowable extension have to cope with the greatly increased axle displacement, they also have to cope with a much higher work rate as the axle now travels much further up and down much faster than before.

In fact to cope with the radically improved suspension travel, shock absorbers with an extended length of 32” are needed! Grab yourself a tape measure and take a quick look at just how long 32 inches really is, especially when compared to standard front shocks.

Of course these longer shocks required much more mounting room and so the space for the new shocks was found up inside the wings. Believe it or not the top mount for the shock is actually just bellow the top skin of the wing, not unlike the height of the mount on Coil Sprung vehicles.

Nigel discovered that there was more to fitting long travel shocks than simply bolting them in place on tall brackets. The GON2FAR system also had to include a special brace to distribute the greater loads that extreme off roading can impose in the Chassis mounting points.

Brakes

Finding your new suspension system has so much new travel that it pulls out and disconnects the original flexible brake hoses would be an exciting experience to say the least. To cope with this and the higher work rate and exposure of the brake hoses the GON2FAR system uses longer, stainless steel flexible hoses.

Lift and track

The GON2FAR Suspension system can be expected to give approximately 1 1/2” to 2" of lift to the vehicle. This is the same amount of lift incorporated by Land Rover in the military version of the 109. During testing this degree of lift did not adversely affect the stability of the vehicle. In fact the amount of lift is offset to some extent by the fact that the track must be increased 3" to allow the kit to work. This is to allow for the greater articulation without the wheels or tyres fouling shock absorbers or bodywork.

Easy Fitment

There’s not much use in designing a system that requires so much vehicle modification that you might as well have started from scratch! Therefore, although requiring some competent chassis welding, Nigel has had to ensure that fitment of the system is simple, rapid and within the capabilities of a good home mechanic.

Rear suspension and the Revolver Shackle Kit

Having advanced the front suspension design so much, Nigel next turned his attention to the rear axle

Here Nigel decided that given the already improved articulation over the ‘standard’ front axle, A system incorporating Revolver Shackles could be used that would give a more than adequate match for the GON2FAR system at the front.

Originally developed in America Revolver Shackles increase articulation by opening up to allow the axle to drop further. They also incorporate a pivot to prevent the build up of twist in the spring during articulation. This pivoting action relies upon the same principles used the by the GON2FAR front mount.

The use of the Revolver Shackles has allowed the rear suspension kit to be developed as a bolt-on kit. As in the GON2FAR front end, space again has to be found for long travel shock absorbers. They are now mounted across the vehicle, reaching all the way up to just underneath the floor. The top mounts of these shocks is located on a new, purpose built cross member.

As anyone using 750x16 tyres with parabolic springs on a Land Rover will know, the tyres will rub the inner arches during articulation. With the increased articulation the Revolver Shackles allow the track width must be increased using spacers or off set wheels to prevent this becoming a problem.

Once again a long travel prop shaft and an extended stainless braided brake hose complete this comprehensive kit.

Find out more

Those of you who have been involved in any development project will know that the theory and experimentation required to advance and perfect the end result would probably take up a whole years worth of Difflock magazines to recount! Nigel understands this too and so he has created a dedicated web site and resource centre where you can find out more about his work and that of other like-minded enthusiast who are stretching the boundaries of leaf sprung suspension systems. Even better, if you can’t spare the years of effort and substantial amount of cash required to develop your own system, you can now buy these two suspension systems as complete kits from Nigel and find out for yourself just what GON2FAR really means!

Click on this link for more details on GON2FAR systems - www.GON2FAR.co.uk