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MARCH 2025


4x4 Outdoors Show Brisbane



Steering Knuckle For D-MAX/MU-X/BT-50

Fulcrum Suspensions Hall: Lower RICC Stand: 722

TRC6680 Steering Knuckle Kit - Bump Steer Correction - designed to optimise the steering geometry

This product does not require engineering or mod plating and it is completely legal. TRC6680 is VSB 14 approved, this product is also ADR compliant. It works the exact same as installing an upper control arm. 

Our engineering team have both assessed and conducted 3rd party testing on the aftermarket front knuckle (TRC6680) to VSB14 loads, for a front axle rating of 1650kg using FEA analysis. It has been found to comply and exceed the strength requirements. This product can be fitted with any GVM upgrade.

VSB 14 & How this product is compliant & legal

VSB 14 is the legal underwriting that affects aftermarket modification, where TRC6680 is classified as owner certified. Meaning that no engineer or certification is required after the product has been installed. This works the exact same as installing an upper control arm, shock, legal lift kit, spring or airbag kit.


ADR & How this product is compliant & legal

The Australian Design Rules (ADRs) are our national standards for road vehicle safety, anti-theft and emissions. All new road vehicles manufactured in Australia and imported new or second-hand vehicles, must comply with the relevant ADRs when they are first supplied to the Australian market. There is no specific underwriting related to steering knuckles, the same as there isnt for control arms, shocks, etc. As such there is no ADR compliance to be followed. However, when testing this product it met OE design standards.


It is essential to highlight that there are no Australian Design Rules (ADRs) specifically addressing the 'robustness of a vehicle.' Consequently, VSB14 serves as an excellent guide and, in practice, is the primary standard to reference when considering 'in-service modifications.'


Comparison examples of other in-service bolt in modifications that also do not require engineering / mod plate certification but are a similar replacement part / upgrade to the superpro steering knuckle, include:


1.      Leaf spring - Parabolic vs. original: Despite notable differences in shape and design, both comply with Original Equipment (OE) standards.

2.      Front Strut - OE to Formula 4x4 or equivalent: Transitioning from the OE to Formula 4x4 or an equivalent strut demonstrates conformity.

3.      Bull Bar - Before and after fitment: The installation of a bull bar poses no issues.

4.      Control Arm - Replacing a steel control arm with an Alloy Control Arm: This substitution maintains compliance with standards.

SuperPro components, implemented as 'in-service modifications,' have undergone rigorous testing in accordance with appropriate engineering standards, instilling unwavering confidence in the quality of our products.


  1. Vastly improved handling and overall vehicle dynamics, building driver confidence and supporting the fact that the car “just feels a whole lot better”. 
  2. Improved stability, day-to-day driving as well as touring/off-roading.
  3. The driver will not have to constantly correct the steering or fight lane change assist.
  4. Less driver fatigue meaning higher levels of concentration and reduced chance of being involved in an accident
  5. And finally, reduced tyre wear meaning better contact between the tyre and the road

If you are a trade customer and wish to purchase this part at a special trade price, please call our trade sales department within business hours on 1300 360 922 - this is the direct trade phone number. 1800 684 255 is the general phone number for retail and trade customers. 

The Isuzu D-Max, MU-X & Mazda BT-50 suffer from chronic bump steer resulting in radically increased tyre wear which is apparent in standard height vehicles, but becomes more prominent as you lift them.

These brand-new steering knuckles resolve this issue and are suitable for both standard height and lifted vehicles.
TRC6680 steering knuckles replicate all the features of the original equipment (OE) knuckles and come with identical mounting provisions for a seamless direct replacement.

It is produced using a hot forged 4140 AISI steel which is then post machined, heat treated and finished in black e-coat for maximum for corrosion protection.

Combine a pair of TRC6680 steering knuckles with a set of TRC6590 upper control arms in your vehicle and you will solve your premature tyre wear, sort your alignment issues and have your vehicle driving well as intended.

Can Regular Wheel Alignments from a Suspension Specialist Fix this issue? 
The short and simple answer is no. You could get a wheel alignment from a suspension specialist every 5000km and rotate your tyres every so often to help reduce tyre wear. But this only mitigates the issue it is not a fix. Doing regular wheel alignments serves as a band aid fix to the actual problem.


Alternative fixes that are NOT a Steering Knuckle. 
Two years testing in order to design a fix for this issue has taught us. The issue with just doing an upper control arm is you cannot get enough offset in an upper control arm to get a corrective fix for bump steer. The steering rack pickup point needs to be raised to fix the issue. A UCA (upper control arm) can get some change to help with bump steer but wont fix the issue.

If an upper control was designed to fix the bump steer issue you would end up with so much caster that you would end up with tyre clearance issues, giving your car a new problem. 

TLDR; You could use an upper control arm to help improve bump steer but it will NOT properly fix the issue and if you did design a UCA which did in fact fix the problem it will cause other issues in turn (fixing one issue but causing other problems). The steering knuckle from SuperPro is designed to fix the issue with zero consequences.

Why is bump steer an issue?
Bump steer is the change in toe in or toe out as the ride height of the vehicle changes. This occurs constantly when driving as the vehicle oscillates over the bumps in the road. This movement is magnified by increased weight from towing, high loads, accessories or a suspension lift . An excessive amount of bump steer will cause extreme amounts of premature tire wear, which is what field reports have shown to the development team first-hand and through their own R&D testing.


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