Do I need an engineering signatory for minor modifications?Vehicle modifications fall into three distinct categories: ‘Owner certified’ minor modifications which can be accepted for registration purposes without formal certification.
‘Engineering signatory certified’ modified production vehicles.
‘Engineering signatory certified’ individually constructed vehicles.
Owner certified minor modifications are generally those modifications which were optional equipment for the vehicle concerned. Owner certified modifications also include some non-standard modifications of a minor nature which do not affect the level of safety, strength or reliability of vital systems such as brakes and steering. These modifications have little or no impact upon the vehicle’s level of compliance with the Australian Design Rules.
Examples of minor (owner certified) modifications are:Engine changes where the capacity increase is less than 15% above the maximum size engine available for the vehicle (providing no major structural modifications are necessary and where noise and/or exhaust emission ADRs apply, all standard equipment such as carburettors, exhaust systems, exhaust gas recirculating valves, oxygen sensors and catalytic convertors relating to noise and emission control are retained and operate correctly).
The fitting of a proprietary sunroof (if the modifications are of a minor nature only).
Fitting a ‘package’ available as optional equipment for the vehicle (eg front disc brakes, power steering, alternative transmission and bucket or bench seats).
Additional lighting eg fog & driving lights.
Alternative wheels and tyres within the owner certified limits set by the Authority (see Vehicle Standards Information Sheet No. 9 Guidelines for alternative wheels & tyres).
Fitting of handling enhancing suspension components such as roll stabiliser bars and up-rated shock absorbers.
Major modifications which fall outside the category of minor (owner certified) modifications require submission of certification by an RTA recognised engineering signatory. This is usually in the form of an Engineering certificate prepared by the signatory.
Any modification that would affect these crashworthiness safety standards should only be made on the advice of the vehicle's original manufacturer or an engineering signatory.
Bodywork and interior
There are general requirements concerning alterations to the bodywork:
No alteration may cause a hazard to persons due to exposed sharp edges or projections; and
No alteration may cause a reduction in the level of safety or overall strength of the vehicle.
