In the world of 4X4, vehicle suspension is everything. Our suspension is what determines everything – from the tyres you can fit, to the quality of your ride, and the amount of that all-important ‘lift’ you get from your vehicle. But for the uninitiated, modern suspension systems can come across as overly complicated and impenetrable.
Thankfully, if you can look past the jargon, the principles and the fundamentals remain very much the same today as they did back in the early days of automotive development.
Here, we get to grips with the basics of suspension, answering some of the most common questions regarding suspension upgrades in a general guide that should form a solid foundation for the rest of your suspension queries.
It’s all about the lift
When it comes to lift, you must understand that adding lift to your 4X4 will raise its centre of gravity. If you use poor quality suspension or suspension that is not compatible with your specific vehicle, this can make it less stable and less comfortable to drive.
Premium suspension is designed to offset this, particularly the suspension from specialist brands like Terrain Tamer and Old Man Emu. It’s all about finding a balance between the amount of lift, the stability of the vehicle, it’s off-road durability, and the quality of the ride overall.
What about the tyres?
Your tyres and rims will need to fit without making contact with the vehicle body or any other components. Always buy your wheels last, as once you’ve added more weight, you might find the clearance is less than you’d hoped for.
Factory suspension or premium suspension
Whether you leave your stock suspension in-place or opt for an upgrade will depend very much on how you intend on using your 4X4. If you are using it to do the daily school run then the factory suspension should be suitable but even then, be aware that just because it’s fitted as standard, that doesn’t mean it’s the best suspension for the vehicle.
All vehicles are built to a price-point and components are developed not only for performance but to meet that price point.
For those that want to take their vehicles off-road and do some serious over landing and green laning, look towards premium upgrades that can offer different options that manufacturers might never have considered.
Are my shock absorbers long enough?
Fitting an integrated suspension kit will generally ensure that the shock absorbers are the right length for the supplied coil or leaf springs. That being said, fitting lift springs with existing factory shock absorbers means the shocks can fall short in certain cases.
A new set of springs on an older vehicle will very rarely give you the results you want. Indeed, if they are paired with old shock absorbers, the replacement springs are only going to have to work harder and will fail again sooner.
The same is true of pairing new shock absorbers with old, worn-out springs. If your suspension needs replacing then you’ll want to swap it out entirely with a brand new suspension kit. It’s all or nothing.
Modern suspension systems can seem complicated, but many of the principles involved date back to the early days of automotive development. Here, we try to cover some of the most common questions we get asked about suspension upgrades.
There is no single set of answers which apply to every vehicle and suspension type though, so this is intended as a general guide only.
“How much lift can I get?”
We are constantly being asked for lifts of 2 inches or more, and while this is fine for some vehicles, it will cause a lot of problems with others. Specialist brands such as Old Man Emu and Terrain Tamer spend a lot of time and money developing and testing their products and trying to find the best balance between amount of lift, vehicle stability, off-road durability, drivetrain alignment and ride quality both on and off-road.
Adding any amount of lift to a vehicle will raise the centre of gravity, but most premium suspension packages are designed to be suited to daily use and are comfortable and stable. However, adding a larger amount of lift, typically 3 inches or more, can make the vehicle less stable in cornering, less pleasant to drive, and less useable – both on and off-road.
“What tyre size can I fit?”
When fitting larger wheels and tyres, we always recommend taking measurements to be sure that your chosen tyre size will fit without contacting the vehicle body or other components. This should be done after adding any additional weight (such as winches, bumpers, roll cages, etc) and after upgrading your suspension. It is never a good idea to buy your wheels and tyres first – and then have to upgrade your vehicle to make them fit.
“Is factory suspension the best option for my vehicle?”
Although it seems logical that all vehicle manufacturers would fit the perfect suspension when the vehicle is new, this is often not the case. Firstly, most vehicles are built to a price-point, so components are often developed to achieve the best results within that price point. Secondly, 4×4 vehicles and pickup trucks have a wide range of uses, and very few manufacturers have ever catered for this by offering upgrades such as different spring rates or shock absorber valving.
Depending on vehicle age, differing usage patterns and mileage covered, factory suspension components become fatigued and less efficient, corrosion can set in, and safety issues can arise. When this happens, it may be difficult or prohibitively expensive to obtain OE replacement parts.
“Can I just replace part of my suspension?”
While it may be tempting to economise and just replace the springs on an older vehicle to achieve some lift, or to just replace one or more shock absorbers to overcome an MOT failure, this is usually not recommended. A set of new springs will not give the best results if they are paired with worn-out shock absorbers – and doing so will cause the replacement springs to work harder and therefore fail sooner. Likewise, fitting new shock absorbers will not cure worn-out springs and can reduce the lifespan of your new shocks.
“Are my shock absorbers long enough?”
Fitting an integrated replacement suspension kit will normally ensure that the shock absorbers are the correct length for the supplied coil or leaf springs. However, if you fit lift springs with your existing factory shocks absorbers, in some cases the shocks can be too short and can ‘top out’ at full extension. This varies by vehicle.