Heavy vehicle modifications

The NHVR has classified the type of heavy vehicle modifications that require approval, either by an Approved Vehicle Examiner (AVE) or the NHVR. For minor modifications (that don't require approval) the NHVR cannot provide an exhaustive list, but general guidance is provided below on the limited type of modifications classified as minor.

The Heavy Vehicle National Law (HVNL) does not specify qualifications for mechanics undertaking service or repair of heavy vehicles, but sets the standards that heavy vehicles must meet. The qualifications of service providers who service or repair of heavy vehicles are currently the responsibility of the various state-based legislative authorities that administer the vehicle service and repair industry, including specific licensing arrangements.

Minor modification

Minor modification includes the fitting of optional equipment or alterations to a vehicle within manufacturer’s specifications that do not cause the vehicle to be non-compliant with heavy vehicle standards. Should clarification be required on whether a modification requires approval the NHVR will make a determination.

Examples include; additional lighting, aerials, air conditioning, alarm systems, plastic shields for lamps and windscreens, and manufacturer’s wheel and tyre options (that do not affect the Gross Vehicle Mass (GVM) or Gross Combination Mass (GCM) rating of the vehicle). These modifications do not require approval provided the vehicle continues to be within manufacturer’s specifications and comply with the heavy vehicle standards.

Modifications under the Code of Practice (Section 86 of the HVNL) - require approval by an AVE

These modifications are those outlined in the NHVR Code of Practice for the Approval of Heavy Vehicle Modifications (PDF, 655KB) (the Code). This includes complex modifications that can affect the safety of a vehicle if not performed properly. The modifications included in the Code are based on accepted vehicle engineering practices and the requirements of the heavy vehicle standards. The Code also supplements the recommendations of the original vehicle manufacturer in relation to vehicle modification techniques or standards and provides guidelines where manufacturer’s specifications do not exist.

The Code applies the existing National Code of Practice Vehicle Standards Bulletin (VSB 6) – Heavy Vehicle Modifications

Vehicles modified in accordance with the Code maintain the vehicle’s compliance with the heavy vehicle standards. These modifications require approval by an AVE who will issue a modification certificate and ensure a modification plate is affixed to the vehicle if the vehicle passes inspection. The vehicle may require a further inspection subject to particular jurisdiction registration laws.

Modifications made under the Code do not require direct approval by the NHVR.

Modifications outside the Code of Practice (Section 87 of the HVNL) - require approval by the NHVR and an AVE

These are modifications not covered by the NHVR Code of Practice for the Approval of Heavy Vehicle Modifications (PDF, 655KB) and may cause the vehicle to be non-compliant with a heavy vehicle standard. These are usually significant or extensive modifications that have the potential to seriously affect the safety of the vehicle and its operation on the road by affecting the vehicle’s design, strength, structural integrity and handling characteristics. These modifications require approval by the NHVR.

A Modification application (PDF, 526KB) must be submitted to, and assessed by, the NHVR. An engineering analysis (certification) by a suitably qualified person may also be required depending on the extent of the modification and the potential effect of the alterations on the vehicle’s safe operation.

When the NHVR approves a modification, a Statement of Requirements – Requirements for Modification Approval (Statement of Requirements) will be issued detailing how the vehicle modification should be undertaken and any related inspection requirements. These modifications require approval by an AVE who will issue a modification certificate and ensure a modification plate is affixed to the vehicle if the vehicle passes inspection.

The vehicle may require a further inspection subject to particular jurisdiction registration laws.