Last week, a heavy vehicle fleet manager in Australia asked me a common question:
Do I need a VASS (AVE) Approval Certificate if replacing a drawbar with one from another manufacturer?
This blog post breaks down the answer with practical insights for transport operators, engineers, and compliance managers.
What is a VASS/AVE Certificate?
An accredited sign-off in Australia to confirm that a vehicle modification complies with the Australian Design Rules (ADRs) and Vehicle Standards Bulletin 6 (VSB6). It is a vital part of ensuring roadworthiness and legal compliance for heavy vehicle modifications.
Like-for-Like Replacement (No VASS Required)
If the replacement drawbar is truly identical to the original in terms of exact dimensions, material specifications, load rating, and mounting arrangement, it is generally considered maintenance or repair, not a modification.
According to the official guidance in When is a VASS Approval Certificate Required, modifications that remain within the manufacturer’s specifications typically do not require certification.
Different Design or Non-Identical Replacement (VASS/AVE Required)
If the new drawbar differs in geometry, welding methods, bush arrangement, thickness, or load rating, it becomes a modification under VSB6. In this case, you will need a VASS/AVE Approval Certificate to prove compliance with ADRs. This ensures your vehicle remains legally compliant and safe for road use.
The deciding factor is whether you can prove equivalence:
- If the new manufacturer provides engineering drawings or compliance statements confirming that the part meets the original specifications, VASS/AVE may not be needed.
- If proof is not available, then the replacement is treated as a modification requiring VASS/AVE certification.
Practical Compliance Checklist
To avoid compliance risks, transport operators should:
- Consult a VASS/AVE signatory before making changes.
- Document everything: supplier compliance statements, drawings, and correspondence.
- Err on the side of caution — when in doubt, get a VASS certificate.
Technology Spotlight: RegPlus
Operators looking for quick answers to compliance questions may also find tools like RegPlus useful. RegPlus is an AI-powered compliance knowledge hub for the road transport industry, developed by ModiCert. It provides easy-to-understand guidance based on current regulations, helping operators make informed decisions about modifications and certifications. Here is RegPlus’s answer to our question:
“According to the file When is a VASS approval certificate required_, if the modification is within the manufacturer’s specifications, a VASS Approval Certificate may not be required. However, if the drawbar does not comply with the original specifications or if it involves modifications beyond standard replacement, then it will require a VASS Approval Certificate.
In summary, if the new drawbar manufactured by another company has the same specifications and is considered a direct replacement, a VASS certificate may not be necessary. It is advisable to consult with a VASS signatory for confirmation regarding compliance and any specific requirements.”
Final Word
In summary:
- Direct replacement within OEM specs → usually no VASS/AVE required.
- Different specifications or unproven compliance → VASS/AVE required.
For peace of mind and legal certainty, always confirm with a qualified VASS/AVE engineer.
Written by: Eiman Nosrati (VASS Signatory, CPEng, NER)
Do you need a VASS certificate for replacing a dolly drawbar? Learn when a like-for-like replacement is considered a repair versus a modification under VSB6 and ADRs.
- VASS certificate replacement drawbar
- Heavy Vehicle Compliance Australia
- Dolly drawbar modification VSB6
- ADR compliance heavy vehicles
- VASS engineer Victoria
Need help with heavy vehicle compliance or modifications? Our team can provide you with experienced VASS signatories and provide tailored guidance to support your needs.
