Carry More. Stay Legal. Tow Hard.
Increase your legal payload to 1,249kg with a fully engineered, compliance-ready 3.99T GVM upgrade using Fox 2.5" Remote Res Shocks. Federally approved for pre-registration.
Factory GVM
Was Never
Enough.
The Toyota Tundra's 3.5L twin-turbo hybrid is a powerhouse — but the factory payload tells a different story. Tow 4,500kg and you're already blown past your 700kg payload limit with two passengers and minimal gear on board.
The rear axle load of 1,850kg gets crushed the moment you fit a tray, canopy or serious touring setup. We build fully engineered GVM upgrade packages to get your Tundra properly sorted — legal, safe, and ready for anything.
- ✕Factory 700kg payload — blown out with 2 passengers and gear
- ✕Over GVM — every trip is technically illegal
- ✕Unsafe under braking and cornering with a full load
- ✕At risk of insurance void in an accident
- ✕Non-compliant for ATO tax deduction purposes
- ✕Factory rear axle limit exceeded with any serious build
The Right
Upgrade
Pre-Registration federally approved. Price includes SSM Federal Engineering and installation. Freight not included.
*Freight not included · Pre-registration only · Post-rego coming soon
- ✓ Front Fox Performance Elite Series 2.5" Coilover Remote Reservoir DSC Shocks
- ✓ Rear Fox Performance Elite Series 2.5" Remote Reservoir DSC Shocks
- ✓ BDS Front Upper Control Arms
- ✓ Rear Outback Kitters Coil Springs +50, 100kg or 300kg
- ✓ Boss Air Double Bellow Airbags
- ✓ SSM Federal Engineering
- ✓ Installation
Approved with factory wheels and tyres. 2" lift included. Ideal for towing, touring, and work setups — keeps you legal and ATO-compliant.
Book This PackageThe Only Upgrade
Your Tundra Needs
With just one well-engineered package, we take your Tundra from a dangerously underrated 700kg payload to a genuine 1,249kg — nearly doubling what you can legally carry.
The rear axle climbs from 1,850kg to 2,149kg, meaning tray builds, dual cabs with canopies, and heavy touring rigs are finally covered.
Approved with factory wheels and tyres — no mandatory wheel swap required.
Pre-registration compliance only. Post-rego option coming soon. Approved tyre size: 265/65R20.
Is the 3.99T Right
For Your Build?
The Tundra's upgrade is purpose-built for three kinds of owners. Here's who needs it most.
| Details | 3.99T |
|---|---|
| Lift Height | 2" |
| GVM | 3,999kg |
| Payload | 1,249kg |
| GCM | 8,499g |
| Braked Towing Pre-Rego |
4,500kg |
| Front Axle | 1,850kg |
| Rear Axle | 2,149kg |
| Wheel & Tyre | |
| Wheel Load Rating | 1,075kg |
| Tyre Load Rating | 1,075kg |
| Requires Wheel/Tyre Upgrade | ✕ |
| Max. Tyre Size | 265/65R20 |
| Package Inclusions | |
| Shocks | Fox 2.5" R/R |
| Part Number |
AG831002-39F2-11 (100kg) AG831002-39F2-21 (300kg) |
Not Just Another
GVM Program
Knocked Out of the Park
We weren't the first to release a GVM program — we wanted to make sure ours gives you the best outcome. Not just the best products, but the right components and compliance package for each specific vehicle.
Vetted Installers Only
We can't have any random workshop touching your truck. Every installer in our network has been vetted by us personally — quality work done by legends who know what they're doing.
Full Engineering Papers
Every upgrade is backed by SSM Federal Engineering and full compliance paperwork — accepted nationally. Pre-rego approval available across all states, with post-rego options coming soon for the Tundra.
Best Support in the Game
Our GVM experts are available to walk you through the right choice for your specific Tundra build — before and after installation. We want you sorted, not just sold.
GVM Upgrade
Frequently Asked Questions
Everything you need to know before you upgrade your Tundra.
The factory GVM and rear axle ratings simply weren't designed with serious Australian touring and towing use cases in mind. That's why a properly engineered GVM upgrade is so important for anyone using their Tundra the way it was built to be used.
Our goal is to offer a more complete and confidence-inspiring upgrade pathway, backed by stronger supporting information and a clearer compliance position — so you're covered no matter your state or use case.
GCM stands for Gross Combination Mass and refers to the maximum legal weight of the vehicle and trailer combined.
In simple terms, GVM is about how much weight the vehicle can carry on its own wheels, while GCM is about how much total weight the vehicle and trailer can handle together. The Tundra 3.99T upgrade achieves a GCM of 8,499kg.
This makes it a cleaner, more cost-effective upgrade path for most owners. You get the payload and axle capacity increase without the additional expense of new wheels and rubber.
What changes significantly is the available payload headroom. With 1,249kg of legal payload, you can now tow at or near the 4,500kg limit while carrying passengers, fuel, and gear without exceeding GVM. That's the real-world benefit for Tundra owners.
This is where many people get caught out. There is a big difference between a vehicle that has upgraded suspension and a vehicle that has a properly approved and certified GVM upgrade. The Tundra package from America's Garage comes with SSM Federal Engineering certification — accepted nationally for pre-registration approval.
The best way to protect yourself is to use a properly supported GVM upgrade program, keep all paperwork, and make sure the vehicle is modified and certified correctly. The America's Garage Tundra upgrade comes with complete SSM Federal Engineering paperwork — giving you a strong compliance position with any insurer or dealer.
Ready to Sort
Your Tundra?
Talk to one of our GVM experts. We'll walk you through the right package for your Tundra build, your state, and your budget.
Our GVM experts are ready to help — Mon–Fri, 8am–5pm AEST