Buyers Guide to Suspension Lifts for Trucks
So you've been off roading for a while, and hit the limitations of your standard suspension setup. Or you just want to make your truck look bigger. Whatever your reasons, you're looking at a suspension lift. There are a several things to consider while doing this. Firstly, it is not simply a case of fitting longer springs. Depending on the extra height you want, you may well need to change other parts. In this article I will consider lifting a coil sprung vehicle with live or beam axles.
Obviously the first thing you must look at is how much extra height you want. The greater the lift the better your ground clearance will become, but bear in mind that lifting your daily driver and weekend toy by too much will make it a handful on tarmac as it will shift the centre of gravity. The size of tyres you intend to fit should be considered at this point, as larger tyres will make contact with bodywork while your suspension is compressed unless you ensure that the lift is great enough. Each vehicle is different, so I would strongly advise checking on an owners forum such as Mud Club to find out what sizes will suit and indeed what people have found to work best. That done, it is time to start buying parts.
You will need new springs and shock absorbers as a minimum. Consider buying better quality shocks than standard, and now may be a good time to look at those heavy duty suspension parts. If you seek greater axle articulation then you may be able to fit spring dislocation cones, which allow your axles to drop further and ensure the springs return to their seats. On top of these parts, you will need extended brake lines and extended bump stops. Larger lifts may require you to modify or replace the propshafts, again depending on the vehicle. Do not be tempted to skimp on any of these parts, if you cannot afford all of them in one go then collect them together over time before fitting them. You are modifying a critical part of the truck and should ensure that all parts fitted are high quality.
Moving on to a part of the job second only to extended brake lines, you may well need to modify your steering. Lifting the front of your truck (assuming that you have a Land Rover-type design of front suspension) with longer springs causes the axle to rotate forward, as it is held by the radius arms. Your steering will be reluctant to self-centre now, and can make your truck unpredictable. There are several solutions to this problem should it arise, from swapping the radius arms for castor corrected ones to changing the steering swivels for the same result. It really does come down to what truck you have, as even with two identical ones it has been found that some need this adjustment while others do not.
An alternative suitable for trucks with a separate chassis is the body lift. This raises the body from the chassis by a given amount, leaving your suspension geometry unchanged. You can team this with a suspension lift, however some have found that a body lift and larger tyres are a perfect upgrade as it gives the extra clearance under the axles and allows greater articulation. You will still need longer brake lines and may have problems with ancilliary components mounted on the sides of your engine bay along with fuel lines and anything else attached to both body and chassis. You may also find that your bumpers now look a little odd if they are fitted to the chassis, as the body has been raised leaving a gap.
Regardless of which options you choose, having amassed your parts the time comes to fit them. Give your truck a good jet washing underneath, then coat all the bolts you will need to remove with penetrating oil. Do this a few days before you start, and repeat the process. This should save considerable effort and skinned knuckles when you start work. If you do not feel confident, have a garage do the work for you. You will be liable for any mistakes or poor handiwork should it later cause an accident.
All the usual workshop safety instructions apply, but you will encounter some specific dangers. Firstly, spring compressors. These are threaded rods with hooks on each end, intended to squash springs and make them easier to fit. I have heard reliable tales of them slipping off, causing the spring to exit the workshop via the roof. For this reason, many suggest that you jack the vehicle up until there is enough space to drop the new springs in without compressing them. If this is possible with your vehicle then it is a considerably easier way of fitting the parts. Take heed of the usual warnings regarding working with brakes while fitting the extended brake lines, and be prepared to have to replace a few nuts and bolts.
Once everything is fitted and tightened, it is time for a test drive. Take it easy at first, your truck will handle differently. It will tend to lean more in corners and will not fit in most multi-storey car parks. It is worth measuring the overall height of your truck at this point and making a note of it, so you are not caught out by a height barrier which can do embarrassing and costly damage. Last but not least, you must inform your insurer of any modifications. After all that, it is a simple matter of learning to use your new-found ground clearance and tyres to take you where you want to go.
