The Superior Engineering Landcruiser 79 coil kits can be supplied to suit a wide range of applications. We have packages and options from – VSB / State approved kits that use your factory housing in either Bolt-In or Weld-In to our bigger kits that can be Federally approved. These larger Federally approved kits allow a metric equivalent or imperial 35” tire, 4” suspension lift kit, 4 tonne GVM, Wide-Track chromoly housing.
With so many options available Superior Engineering can supply a kit to suit just about any application, whether you’re just a weekend wheeler that has no weight and puts the dog in the back, a Tradie that is loaded through the week and unloaded on the weekends or a fully kitted-out 4T+ tourer.
What is a coil conversion:
On a leaf spring vehicle the spring (leaf) also does the locating on the diff as it travels through the suspension cycle. A coil conversion replaces the factory leaf springs, shackles and bushes and replaces it with a steel fabricated crossmember that supports coil springs between the diff and chassis. The Upper and Lower control arms locate the diff as it travels through the suspension cycle, allowing the spring to do only what they do best – suspend the vehicle. Coil spring design allows the vehicle to have a wide range of spring load characteristics from soft comfy linear, dual rate for loaded and unloaded comfort or heavy duty for those that carry large constant loads. The Control arms accurately locate the diff as it travels up and down and the geometry is finely tuned to reduce dreaded rear steer and allow massive articulation while reducing tire to chassis interference. Link suspension also nearly eliminates wheel hop under acceleration which reduces load on the axles and gears.
Why buy a coil conversion:
While leaf springs have always been known as an economical suspension setup for carrying load and locating the diff, they are far from optimal when it comes to ride quality and offroad performance. Coils springs are available in a huge range of different heights and rates when compared to leaf springs. Coil Springs are readily available with rates to suit all applications whether you’re a heavy tourer or a 4wd carrying no weight. With a coil conversion will often transform your 4wding capability as your suspension is greatly enhanced with more overall wheel travel, added traction and a comfier more controlled ride.
Why buy a Superior Engineering Coil Conversion over other brands:
- The Ultimate diff housing starts with 4140 Chromoly 13.5mm wall housing tubes that are ~900Mpa average Yield Strength where our competition uses ~6mm wall carbon hollow bar that is ~470Mpa, meaning just in the tubes alone a Superior Engineering housing are almost double the strength over our competitors. FEA tests were completed with 15 tonne load on the rear axle, and even then they only showed a deflection in the housing of less than 1mm, no other brand Landcruiser housing come close!
- If material strength and thickness wasn’t enough, we are also the only manufacturer using 90mm axle tubes; almost all other are still using the smaller 80mm axle tube. Utilising a 90mm axle tube greatly increases the overall strength of the housing to resist bending from excessive loading or side impacts.
- Adding to this the center section of our diamond diff is fabricated as standard with 6mm high tensile 830Mpa plate! High Tensile, wear-resistant and Hardened steel plate is the perfect match for the 4140 chromoly outer tubes. For added strength, it has a 4mm High Tensile Diff Guard / Skid Plate added to the rear and bottom of the housing which further protects the pinion gears and diff centre.
- A massive increase in ground clearance compared to our competitors is achieved through the use of larger axle tubes and a wider overall diamond, meaning we do not have weld additional gusseting underneath the diff housing to add strength.
- Overall width of the diamond center is wide and tapered, which adds a massive amount more structural integrity and strength, the additional internal gussets of the diamond center not only help with overall strength but provide channels for oil flow aiding in cooling.
- Superior Engineering is the only Australian manufacturer to use Aerospace grade – 300M axles made exclusively by RCV – ‘The manufacturer of the world toughest 4WD axles!’. These axles are the same material and hardening used in Ultra4 race cars, trophy trucks as well as an array of offroad weapons in the USA and around the world, and they are at no extra cost. The RCV 300M axles offer a lifetime warranty against breaking!
- The RCV axles are attached to the housing using a billet 4340 drive plate. Factory axles are prone to break once a wheel bearing becomes loose, the use of a drive plate almost stops the fatigue caused wheel bearing play and provides a stronger overall axle drive assembly.
- Unlike our competitors the 79 Series Coil Conversion features a complete wrap-around chassis structure that encapsulates the complete chassis. We then combine a bolted clamp system both top and bottom with through-the-chassis and individual location bolts to completely secure the OE chassis and Superior Crossmember together as one strong unit. Other manufacturers often just use 2 x L plates bolted to the chassis and they do not connect to each other allowing a great deal of movement around the chassis causing rust.
- Superior Engineering has a long and respected history in the 4wd industry. With a pedigree forged from building some of Australia’s best and most innovative 4wd components and a passionate sales team that live and breathe anything offroad. Not to rest on our laurels, we have designed all of our rear coil kits to make full use of the amazing front suspension kits that we have available. The Superflex and Hyperflex radius arm kits are incredibly popular and are perfectly matched to the Rear coil kit adding massive articulation to great driving manners. This gives our customers peace of mind knowing they will have a product that is guaranteed to outperform and outlast all others!
- The Superior coil kit offers over 100% more chassis bracing than other coil conversions and is designed and tested to far EXCEED all OE and ADR chassis loading criteria. The Superior Engineering Coil conversion kit is the only one on the market to support the chassis along the almost whole rear section of the vehicle, with bracing that runs in conjunction with all of the tray mounts that support load. Some competitors kits only brace in-between that center tray supports, this then relies on the tray so support the center-point bending load caused by the coil suspension.
- With our kits you can fit both long range – side and/or rear Browns Davies tanks.
- Our Diff upgrades kits come standard with a corrosion resistant Black powder coat finish; other optional colors are available at NO EXTRA COST! Not an additional extra like some manufacturers.
- Superior coil kits are packaged to allow customers the ability to choose a setup to suit their exact requirements, whether it’s remote touring, towing, camping or extreme 4wding we have a setup for you. All Superior Engineering kits are advertised with no hidden costs, we can help with everything need to transform your vehicle, from supply, fitting and engineer approval, we are there to help you build the most capable vehicle to suit your needs .
- Only Genuine OE bushes are used in all our suspension links , we highly recommend you never fit an Upper or Lower control arm in a 4wd rear suspension with anything apart from genuine OE bushes, poly bushes cannot handle continuous articulation and torque loading that is seen in general offroad use
- We are the only manufacturer to offer ITS technology on all Superior Engineering Tierods Draglinks and control arms, this is a patented seal and groove design that stops rust from forming inside your control arms , no other brand cannot offer this extra protection and peace of mind
- Long arms are a standard feature in our coil conversion, this style extended Arm greatly reduces rear steer that other brands badly suffer from. The Long arm geometry reduces diff-steer and allows the vehicle to transfer power to the ground much more efficiently rather than just trying to drive the diff under the vehicle and upset the center of gravity. Coil kits for Toyota 70 series cruisers that utilise the factory spring hangers for the lower link mount, drive terrible and do not climb hills as well, when compared to a well-designed 4 link Long-Arm setup. Short lower links are often linked with poor Anti-squat geometry and increased diff steer when articulating.
- The Superior coil kit has the best geometry of any Landcruiser 70 series kit available! By not trying to use the factory mounting locations we were able to get the link position and length perfect allowing for an excellent handling and performing kit whilst achieving huge amounts of diff travel and flex!
- A massive advantage in choosing Superior Engineering for your coil conversion is the ability to match your front suspension By choosing from an array of street legal steering and suspension options that no other company can offer, such as the patented Superflex arms, the amazing Hyperflex arms as well as ITS 4140 Chromoly Upper control arms and the all new – Superior Drag link featuring the World’s strongest steering joints for Toyota 70 series.
A full set of comprehensive Instructions is supplied in print form at time of purchase and are also able to be download from our website. In general Coil conversion Kit fitting time can range from 2 days to 5 days depending on the exact kit and options chosen. Ideally it is recommended a workshop be used with a hoist to fit a coil conversion. If fitting a Weld in kit, you will need to use a competent welder or if it is Bolt-in you need sound mechanical knowledge and be competent in fitting and adjusting suspension.