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McCormacks Joins Forces with JMACX, the Inventor of Coil Conversions, for Ultimate Off-Road Performance.

When it comes to off-road performance and vehicle modifications, experience and innovation are the keys to success. That's why the partnership between McCormacks and JMACX is generating a buzz among avid off-roaders. With McCormacks' trusted name and 66 years of industry expertise combined with JMACX's pioneering coil conversions, this collaboration promises to take off-road enthusiasts to new heights of adventure and capability. Let's delve into the exciting world of this powerful alliance and discover how it is redefining the off-road experience.


Trusted Excellence in Engineering: McCormacks has been a trusted name in the industry for over six decades, delivering exceptional engineering solutions and top-notch customer service. With a wealth of experience and a proven track record, McCormacks 4WD has become synonymous with quality and reliability. Their commitment to excellence ensures that every modification and upgrade is executed to perfection, giving customers the utmost confidence in their off-road endeavors.

What is a GVM upgrade?

Your vehicle’s Gross Vehicle Mass (GVM) is the maximum weight your vehicle can carry when fully loaded.  Absolutely everything on your vehicle adds to the Gross Vehicle Mass and needs to be accounted for.  This includes the vehicle itself, any load you’re carrying, fuel, accessories, and also any additional tow ball load from a trailer, camper, or boat. It’s important to understand that your vehicle GVM is not only a safety requirement, it’s a legal requirement as well.  You’ll also notice that your vehicle won’t perform as well when driving close to the manufacturer’s factory GVM specification


JMACX is the innovator and industry leader in coil conversions, 6×6, 4×4 suspension systems, and GVM upgrades for the ultimate vehicle. Giving you the strongest coil conversion on the market with full engineering and road legal in Australia for up to 4 inches of lift and 35-inch tires. With the GVM upgrade, this is the ultimate suspension upgrade for outback tourers, commercial vehicles, and the weekend warrior. Tested and proven in some of the world’s harshest conditions.

We provide upgrades on the following Vehicles.

McCormacks' team of highly skilled technicians is trained in the precise fitting and installation of JMACX suspension systems, ensuring perfect match and optimal performance.


With meticulous attention to detail, McCormacks guarantees that every modification is executed flawlessly, providing customers with a hassle-free experience and the peace of mind that their vehicle is in expert hands.

Toyota Landcruiser 70 Series:

  • 3900 GVM Leaf Spring

  • 4200 GVM Leaf Spring

  • 3900 GVM Coil Conversion

  • 4200 GVM Coil Conversion                                              

  • 4495 GVM Coil Conversion

Toyota Landcruiser 200 Series

  • 3800 GVM Upgrade

  • 4200 GVM Upgrade


Toyota Landcruiser 300 Series

  • 3800 GVM Upgrade

  • 4200 GVM Upgrade

Dodge Ram DS 1500

  • 4200 GVM Upgrade

Ford Ranger

  • 4200 GVM Upgrade

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