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Do You Need a Suspension Lift Kit?

Last updated 03/04/2016

Do you need a lift? According to some, one of the most important modifications to any 4WD is the installation of after market suspension lift kit. Is this really true? Is after market suspension universally a good idea?

Why So Low Out Of The Factory?

Why are vehicle manufacturers bringing out their independent front suspension (IFS) four wheel drives with so little ground clearance? Just a little bit more would be great. It doesn’t need to be huge, just enough to keep the belly off the ground in a typical rut. It seems that standard vehicles can bottom out in the ruts even on an easy track to popular family beach and camping spots. Why not give us a few more centimeters to clear those tracks?

It’s not a matter of cost. What’s it take to increase ground clearance slightly? A tighter pre-load wound up on the spring? The cost is practically zero. Do vehicle manufacturers have shares in after market suspension companies? Are they just being stupid?

There is a good reason – the ride height is purposely chosen in a IFS vehicle to minimize CV angles and minimize failure rate. The drive shafts on a stock vehicle are designed to be perfectly level and the CVs to be completely straight when the front wheels are straight. With straight CVs, wear is minimized and longevity and reliability are maximized. The front wheels spend the vast majority of their time pointing straight ahead, so with level drive shafts the CVs are only significantly worn during the small fraction of a vehicle’s life spent turning corners or when on uneven terrain.

hilux stock suspension

The dead straight drive shaft and CVs on a stock standard 2012 4WD Hilux.

As soon as you lift a vehicle the CVs start wearing out more than they otherwise would. Not a bit more. A lot more. Driving straight ahead is wearing them out due to the non zero angle. So instead of wearing out a small percentage of the time, they are wearing out all the time. The wear is constantly accumulating, increasing the risk of a future failure.

The CVs in a stock vehicle are less likely to fail for two reasons:
1. They will be less worn so will be stronger when faced with a potential failure event, such as a shock load when offroading.
2. Any potential failure event will occur at a lower CV angle, reducing the stress on the CVs.

People often associate a failure with what they were doing at the time. Instead of holding the suspension lift accountable, they’ll blame the fact that they were tackling a demanding track at the time. Or they were showing off and driving too hard. Actually failures have many contributing factors which accumulate over long periods of time. As soon as you lift your vehicle the wear is accumulating and potentially contributing to a future failure. See this article for an explanation on how failure works.

To reduce the risk of CV failure, the differential can be lowered when installing a suspension lift. This reduces the CV angles. Ground clearance will be lost directly under the diff, however ground clearance across the rest of the vehicle will be improved, as well as approach angle and the ability to fit larger diameter tyres. This is no different to installing a suspension lift on a vehicle with live axles. The differential ground clearance is not changed for live axle vehicles.

Get After Market Suspension For Better Performance

After market suspension manufacturers often claim their products afford superior handling and performance. One of the key parameters that determines a vehicle’s handling is its centre of mass. Take a look at a Ferrari or Lamborghini. They are low. Raising a vehicle’s centre of mass degrades its handling, increasing body roll, increasing rotational inertia, deteriorating steering feel and increasing the risk of rollover. So right off the bat, all other things being equal, a lift kit will degrade handling.

Apart from lowering the centre of gravity, the other way to enhance handling, given suspension geometry and linkage design is already fixed, is stiffer suspension (with matched shock absorbers). After market suspension is often stiffer than factory suspension. Stiffer springs means they will sag less under the load of the vehicle, providing lift. Stiffer springs also have increased load carrying ability. Many after market springs are provided for increased load carrying so again they’ll be stiffer than stock springs. Stiffer springs do enhance steering response and reduce body roll. But stiffer isn’t better. The vehicle manufacturer could have easily fitted stiffer springs without additional cost. The spring stiffness is a compromise between handling, load carrying ability, passenger comfort, articulation and traction over bumpy terrain. The vehicle manufacturer picked a stiffness they thought was the best compromise. Stiffer springs aren’t superior quality, they simply offer different advantages and disadvantages. So in my opinion you wouldn’t get after market suspension because it’s universally better in terms of performance. It’s different. Get it if you want to carry heavy stuff or you want increased ground clearance and articulation. If you want superior on-road handling you’d lower your vehicle and fit stiff springs.

Reliability

We’ve already discussed how lifted suspension negatively impacts CV reliability. What about the reliability of the suspension itself? The stock suspension is reliable. It’s simple and the geometry is well constrained to ensure it stays safe. There isn’t much that can go wrong. Imagine how many hundreds of thousands of vehicles the manufacturer sells, most running stock suspension. Mining, agriculture, rental vehicles, commercial fleets – they’re all stock. For the small fraction of vehicles running after market suspension, in my experience they account for a disproportionate quantity of failures. Over extension of ball joints, impacts between various suspension components due to flawed suspension travel, strut failures, mounting bolt failures – these are problems I’ve seen in vehicles with after market suspension (in addition to CV failures). Maybe it’s because those vehicles are driven over tougher terrain and with heavier loads. Regardless, stock suspension is reliable in my experience. I wouldn’t get after market suspension for the purpose of increased reliability.

Shock absorbers wear out so it’s possible that after market shock absorbers could last longer. So maybe you’d consider after market shock absorbers if you wanted greater life out of them. However the slow deterioration seen in shock absorbers is not something that will see you stuck out in the bush. If reliability is defined as simply being able to drive then longer lasting shock absorbers don’t really offer enhanced reliability but will offer better performance on bumpy surfaces compared to worn factory shock absorbers.

What About Lifting Live Axles?

Installing a suspension lift on a live axle still degrades handling through increased centre of mass and worsens reliability of UV joints but not to the same extent as CVs in independent suspension. Although universal joint angles are increased, the change in angle is much less when compared to the same lift height on independent suspension and the effect on wear and longevity is much less. This is why live axles are preferred for extreme offroading. They can be configured for huge lift and articulation without effecting strength as much.

Do You Need Big Flex for Going Offroad?

With open differentials it pays to have good flex in your suspension so that all wheels maintain firm contact with the ground. With differential lockers (or traction control) it doesn’t matter if you lift a wheel. The grounded wheel will have more traction because all the weight is on that wheel, and it will receive all the torque through the diff locker or traction control. If you want to maintain driveability on road and minimize increasing the center of mass of your vehicle you are better off getting selectable diff lockers than changing the suspension to get more flex.

If you are doing hard core trails then more flex does have advantages. It keeps the vehicle more stable which is useful if for example you are pushing the limits of traction and inclination. Lifting a wheel causes instability where the vehicle may rock back and forth, potentially triggering a loss in traction or worse a rollover.

When To Get After Market Suspension

In my opinion you should get after market suspension if you want to carry heavy loads for long periods of time and / or if you want improved off road performance through increased ground clearance, articulation, flex, approach angle and departure angle. Another reason is if you want to fit larger diameter tyres to your vehicle. Get some experience with your vehicle before deciding on a lift kit. Does the rear end feel saggy and sloppy when you’re fully loaded? Are you bottoming out on the tracks you usually drive on? If you answer no to both of these questions then maybe you don’t need after market suspension.

Lift your vehicle by the minimum you can get away with. This keeps the centre of mass as low as possible, minimizes negative effects on reliability and hopefully keeps your 4WD legal. Increasing lift increases wear on your CVs disproportionately. A small lift doesn’t make much difference. A large lift means you’ll probably break CVs every so often.

For me, the front end on my hilux was a bit too low for what I wanted to do. It would often beach itself too easily in soft sand and would clip the ground on relatively tame rocky trails. I also didn’t want to lose ground clearance when fully loaded for touring. So I got a small lift – 40mm. And I got stiffer rear springs rated for constant heavy loads. The lift I got is below the 50mm lift limit enforced in most jurisdictions in Australia to keep it legal. Remember you must keep the total lift below the limit. This means suspension lift + body lift + lift garnered through larger diameter tyres must be less than the maximum allowable lift according to the law in your state or territory.

Types of Lift

There are a few ways of lifting your vehicle. Some legal, most not. I’m no expert on vehicle modification laws so do your own research. This is my interpretation of the limited and possibly inaccurate information I’ve come across regarding suspension lift in Australia.

Strut spacers: This is a spacer between a coil strut and the strut mount. It shifts the entire assembly down. This introduces potential problems with over extension of suspension components / steering linkages and bump stops no longer adequately limiting travel. I understand strut spacers to be illegal.

Spring over: This is where leaf springs that have been designed to run under an axle are re-positioned on top of the axle, providing a lift equivalent to the thickness of the axle. I understand spring overs to be illegal.

Extended shackles: This is installation of longer shackles on leaf spring suspension. I understand extended shackles to be illegal.

New springs / struts / shock absorbers: This is the only way that I know of to provide a true suspension lift legally without getting engineering certification, as long as certain requirements are met like not exceeding maximum allowable lift height. New springs will be longer and / or stiffer, providing the lift. Shock absorbers are also replaced to suit the spring rate and travel.

Body Lift: This involves installing spacers where the body fixes to the chassis. It does not improve ground clearance but does provide extra room to fit larger diameter tyres. It is not a suspension lift. I think it’s legal as long as it doesn’t impact other systems like SRS airbags and the height of the lift does not exceed legal limits.

Air Bags: These are pressurized bags that provide lift assistance for your existing suspension and are used to adjust ride height and stiffness. The air pressure in air bags can be adjusted to suit different loads and conditions. Their adjustability is what makes air bags superior to other suspension arrangements. The problem with air bags is that they may load the chassis at a position where it is not designed to take that load. Chassis failures have occurred as a result of air bags. Use them for fine adjustment of your springs rather than as a substitute for springs designed to carry the load. Air bags may or may not be legal depending on how they impact suspension travel.

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See also:

Our Hilux Setup

Design Compromise

Bridgestone Dueler D694LT 48,000km Review

Diff Locker vs Traction Control

How Failure Works

Frenchmans Track

How Often Should I Service My Car?

How to Improve Fuel Efficiency

Why No Diesel Performance Chip?

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17 thoughts on “Do You Need a Suspension Lift Kit?

  1. Howdy Joe,

    Really loving your no bullshit approach. It astounds me how many $ city folk spend on their 4wd’s….seems the “setup” is more important than actually using it! Anyway I could go on & on…

    Question; I have a 2013 Triton with Old Man Emu suspension with what ever their standard lift is. I didn’t necessarily want a lift but needed stiffer on back due to fitting a tradesman type tray/canopy. I am really fussy about suspension and am delighted with the OME set up. (I originally had “The Ultimate Suspension” fit a “system” DO NOT go anywhere near those guys, it was unbelievably terrible!!!!)

    Do you think it worthwhile the cost of fitting free wheeling hubs to save front CV joints/fuel/wear and tear. I would need to get 6 new wheels to allow fitting of hubs, this could be anything from $10 for stock steel wheels from other vehicles with correct specs up to heaps for brand new alloys + $300 or so for hubs themselves.

    My Triton is the base model with gear lever selection of 4wd, so no danger of destroying the transfer case at the flick of a switch with hubs unlocked whilst driving.

    Cheers
    Ben

    • Yeah most of the discussion with many of these folk is around setup and “mods”. Not much about getting out and about. I reckon less mods, less working to pay for them, more camping and more fishing.

      I’ve heard good things about ultimate suspension, shame they didn’t perform for you. I had the perception they were premium stuff but have no direct experience.

      I’ve thought about freewheeling hubs. I think the benefits are marginal so decided it wasn’t worth the hassle. So my opinion on freewheeling hubs is maybe. Lift from OME kits is typically modest at around 30 to 50mm so your CVs should still be pretty reliable if that’s the case. Fuel saving I don’t reckon would be much but I have never tested it.

  2. BTW I have a DP Chip that I transferred from a previous vehicle that came with it, cost $150 to be re-mapped. It makes a slight improvement to torque etc but NO WHERE near enough to warrant the $1700 or so price tag, I would be so pissed off if I had paid that!

  3. Hi Joe,

    Thanks for your insights, they seem to make a lot of sense. I am also trying to find the right compromise for me – I am about to spend a few months with my young family of 5 travelling through the Kimberley and central Australia and hope to get off the beaten track where possible. I own a 200 series land cruiser and plan to fit a winch to my Sahara bar, and will be towing a 1.5 ton hybrid camper plus all our gear, water,fuel and people etc. My vehicle already naturally slopes down to the front, and fitting the winch on the front will only exentuate this….
    Whilst I don’t really want a lift kit for the sake of it, I am being told ( mainly by people that sell these kits!) that a suspension upgrade is almost essential given the weight we will have on the vehicle and the tracks we will be travelling on. I am weighing up an old man emu set up involving a very modest lift (25mm front and 20mm rear) vs a respected local off road mechanic who has suggested a 50mm front lift and 40mm at the rear using blistering shocks, king springs and air bags for the rear which can be deflated when not towing. I am also going to get a new set of all terrain tyres with a marginally larger rolling diameter.
    Any suggestions welcome.

    Cheers,

    Andrew

    • Hey Andrew yeah sounds reasonable dude, you don’t want sagging suspension when hitting the tough stuff. Marginally larger tyres are good too, that’s what I did. Keep the lift to minimum. Apart from lift, ensure spring rate is for heavy loads. You can get no lift but replace the springs with firmer springs. Lifted springs will still sag too much if spring rate is not adequate. Higher spring rate will handle the heavy load better but will yield a firmer ride when unloaded.

  4. Hi Joe, any thought would be appreciated as to why a distinct bass sounding drone noise inside car commencing at 60kph plus and sometimes remaining all the way down to 5 kph, possibly depending on various road surfaces, has developed on my 2008 vx cruiser with KDSS, when a 40mm old man emu upgrade was fitted.
    Thank you Glenn Phillips

    • Hey Glenn not sure mate. Could be something to do with the KDSS going out of whack due to the lift and constanty trying to correct. Try pulling the fuse to the KDSS and see if it goes away. Does it change when you put clutch in / go in neutral? Change with engine RPM or gear selection? Any other mods installed at the time? I’d try a vehicle specific landcruiser forum for more expert advice.

  5. After explaining cv wear in relation to lift, you still lifted your vehicle .
    So I take it you are willing to compromise a little for the sake of a lift ?
    Im considering a small lift, 40-50mm as my vehicle, a bt50 has such a long wheel base. (I already have 32″ tyres).
    Im trying to improve the ramp over angle as it belles out too much.
    Your thoughts ?
    Cheers Dean.

    • Hey Dean doesn’t matter what you do, you are compromising.

      Big tyres plus lift is a bit stressful. But if you’re often dragging the belly then maybe you need it. You carrying big load up front? Bullbar, winch, spot lights, dual battery etc? Then go for smaller lift and stiffer springs. Stiffer rear end may also help if you have a saggy ass.

  6. Thanx Joe, appreciated.
    Dean.

  7. I just came across one of your articles about engine boosters and went on to read the ‘do you need a suspension lift kit’ article. Both relevant to me at the moment, and as a ‘non mechanically minded person’ it is in terms I actually understand. I know I don’t need a suspension kit for any other than reason than re-levelling my front end after the sag of fitting a bullbar and winch. I would like to know your thoughts on just putting in spacers in the front to return height to standard. Would this place the same stress on the suspension components as actually increasing the height? Thanks in advance

    • Hey John see “strut spacers” in the article. Generally they aren’t a good idea. People have had strut failures caused by strut spacers. Maybe, for correcting a bit of sag, you could use a strut spacer no more than 5mm thick which would give you about 10mm lift. There’s still risk by not as much as bigger spacers. Stiffer spring is the proper solution.

  8. Thanks for the reply and explanation on best way to go. Any recommendations on an appropriate spring manufacturer?

    • I’m not sure I have no personal experience purchasing springs alone. I bought ironman lift kit which came with springs and they’re fine. I’ve heard of King springs but dunno much about them.

  9. As a total 100% newbie to 4×4 (just bought a Triton today) I would know I want slightly bigger tyres than the stock tyre and the a little bit of security of knowing my diff is less likely to get stuck on my travels. Not been super rich what is my best cost effective option?

    • Yo Peter it all depends on what you are trying to achieve. The most cost effective is doing barely enough so that your vehicle is just capable of doing what you need it to do. Often this means keeping it stock. I wouldn’t upgrade tyres and suspension just for security with no regard for the intended application. People in the 4×4 community will tell you to do that coz they are either trying to sell you something or they’re addicted to throwing money at their car.

      What sort of work will you be doing with your Triton? Maybe get some experience first with the vehicle, understand its limitations, understand what you want to do with it, and then decide what modifications you want. As security, for the first few times, go out with mates and / or don’t do anything too difficult.

  10. Great advice OBJ, in nearly 30 years of owning 4×4’s I have done fine with just swapping tyres from highway to all terrain and using tyre pressure adjustments to suit environment. Any time I’ve been bogged or struggled with a tough off road situation the other lifted vehicles with increased tyre size have nearly always met the same fate. I have a limited budget so I have chosen to invest in a bullbar and winch and other recovery gear instead.

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