FYI Tasmanian AIS Inspection Manuals (details legalities / roadworthy of modification

[twr7cx]

For this interested, the Tasmanian Approved Inspection Station Scheme Inspection Manuals can be found at Transport: AIS Inspection Manuals (http://www.transport.tas.gov.au/ais/ais_inspection_manuals)

Relevant to modifying Land Rovers is the Light Vehicle Inspection Manual down the bottom.

Most relevant are:
Appendix C: Suspension Modifications - pp. 89 - 90
Appendix D: Lift Kits & Suspension Modifications - p. 91
Appendix H: Mudguard and Mudflap Requirements - p. 99
Appendix O: Modifications Brochure - pp. 129 - 148

[twr7cx]

Some key points for 4WD wheel, tyre and suspension modifications:

Tyres (Section 5: Wheels and tyres pp. 27 - 28):


For a 4WD with beam axles, you can increase tyre width by up to 1.5 times larger than the vehicle manufacturer's widest optional tyre width
Wider wheels/tyres are not to protrude beyond the vehicles extremeties unless additional flared mudguards are fitted
4WD with beam axel can have the wheel track increased by up to 50mm (wheel track is measured from the centre of the tyres)
4WD tyres rolling diameter can be increased up to 50mm larger than that of any tyre designated by the vehicle manufacturer for that model



Suspension Modifications (Appendix C: Suspension Modifications - pp. 89 - 90 and Appendix D: Lift Kits & Suspension Modifications - p. 91):


Body lift kit maximum allowable height increase permitted is set at 50mm for passenger vehicles
Off road vehicles may be granted approval in principal for lifts up to 150mm for modifications carried out in accordance with section LS 7 & 8 of National Code of Practice for Light Vehicle Construction and Modification (VSB-14) - http://www.infrastructure.gov.au/roads/vehicle_regulation/bulletin/pdf/NCOP11_Section_LS_Tyres_Suspension_Steering_V2_1Ja n_2011%20v3.pdf
The suspension travel in the bump or rebound mode must not be altered by more than one third of that measurement as specified by the original manufacturer - http://www.aulro.com/afvb/modified-zone/168727-suspension-travel-bump-rebound-mode.html


Note: nothing is listed in the Body Lift section on p. 91 about no body lifts on a SRS airbag vehicle - although this may be contained within with section LS 7 & 8 of National Code of Practice for Light Vehicle Construction and Modification (VSB-14)


So essentially 2" increase in tyres and 2" in suspension is acceptable without any engineering. Pity that the tyre increase is limited to only 2"'s, as a 2" tyre diameter increase only lifts the vehicle up by 1"...
Strange that they would also approve in principal a suspension lift up to 150mm (approximately 6") but not necessarily the tyres to suit it...

[twr7cx]

For cross reference, you can find the Vehicle Standards Bulletin 14 (VSB 14) National Code of Practice for Light Vehicle Construction and Modification (NCOP) at Vehicle Standards Bulletin 14 (VSB 14) (http://www.infrastructure.gov.au/roads/vehicle_regulation/bulletin/vsb_ncop.aspx)