Engineered in Australia for maximum load capacity, strength, and off-road control — without compromise. 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 4WD and JMACX is generating a buzz among avid off-roaders.
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GVM UPGRADE KITS
- Legally increase your vehicle’s carrying capacity
- Designed for touring, towing, & heavily accessorised vehicles
- Includes engineered certification for peace of mind
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COIL CONVERSION KITS
- For improved ride comfort and articulation
- Better handling under load compared to traditional setups
- Ideal for high-end touring and performance builds
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HEAVY DUTY SUSPENSION SYSTEMS
- Complete matched systems (springs, shocks, components)
- Built for constant loads, towing, and harsh terrain
- Designed to eliminate sag and improve vehicle control
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ALPHA REMOTE RESERVOIR SHOCKS (PREMIUM)
- High-performance adjustable shock technology
- Designed for heat dissipation and consistent damping
- Ideal for off-road performance and demanding conditions
JMACX Upgrades Available
Toyota Landcruiser 70 Series
- Electronic Handbrake Conversions
- 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
Dodge Ram DS 1500
- 4200 GVM Upgrade
Toyota Landcruiser 300 Series
- 3800 GVM Upgrade
- 4200 GVM Upgrade
Ford Ranger
- 4200 GVM Upgrade
McCormacks 4WD x JMACX
McCormacks 4WD's 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.
Need help choosing the right suspension?
Chat with our sales team of 4WD experts or request a personalised quote, we’ll match the perfect setup to your vehicle and lifestyle.
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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
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WHY CHOOSE JMACX
- Engineered GVM upgrades – increase your legal carrying capacity
- Fully compliant systems – certified and engineered (not dodgy mods)
- Australian-made components – built for harsh conditions
- Industry-leading coil conversions – better ride, stability & articulation
- Premium, heavy-duty construction – designed for serious touring and work setups
- Complete systems – not mix-and-match guesswork
- Engineered GVM upgrades – increase your legal carrying capacity