Legal limitations to 4x4 Tyre and Suspension modifications.

[Disco_Rock]

Guys and Girls, long time lurker first time poster, I'm currently looking into upgrading the suspension on my girlfriends Silver 2004 Land Rover Discovery TD5 Classic (coil sprung), we added an ARB steel winch bar and XD9000 Warn winch to it, we're now planning on upgrading the springs and shocks due to fair wear and tear (its @190K) and to cope with the additional weight of the winch and bar (incorporating an ARB/Old Man Emu 40mm raise), and a change from the 255/55R18 Khumo ATR's to something with a little more bite in the dirt preferably an LT and maybe a little bigger, but I've been told I have to stick with the 18 inch Alloys cause she likes them. Ive been trooling the net soo much lately looking for tyres, lift kits, rear bars, snorkels etc that she's starting to get short with me (but I kinda promised I'd do some work to the Disco for her, after all she let me do some engine work to the SS Wagon.) So i thought I'd finally attempt to contribute to this forum, my question is somewhat double edged, 'Whats Good and Works' and 'Whats Legal in NSW'

I have no intention of having the tyres fouling on or protruding out of the guards, or conducting any suspension geometry/mount modifications beyond shocks, springs and a possible steering damper replacement, and I would like to minimise/avoid taking to her guards with a Grinder/Dremel, as she loves her car and enjoys tinkering on it, but not biting off more than she can chew (she insists on doing alot of the work on it even tho I've got considerable experience with a spanner and hammer, which is awesome, our last 'project' last weekend was fitting her UHF radio into the overhead console)

Cheers,

Josh & Shell

[Alex 110]

My understanding is that a total lift of more than 50mm requires an engineers certificate. So with your 40mm OME lift you can't take the tyres more than 10mm extra radius. You could probably go to a 265/60R18 tyre, which will fit without scrubbing or needing guard cutting.
FYI the standard tyre is 29" diameter, the 265/60R18 is 30.5", so 18.75mm increase in radius. It would pass my mechanic on pink slip, but who's to say another mechanic won't check the tyre size against the placard?
Food for thought...

[Disco_Rock]

So that's from the current NSW reg's? Thanks for clearing that up, I've been reading Australian stds, VSI, and it seems to vary from state to state, then you see cool rigs running around on 33's & 35's with 3 inch+ lifts, doesn't help when the GF's family is in WA and I think their rules are different.

What's the go with such limited 'LT' tyres in 265/60R18's, they're all passenger construction!!!

[barney]

This will be a bit to read through, but these are the current laws and guidelines that you need to comply with. They are under review. By a huge working party that include the NSW &ACT 4wd association as a major contributor, along with the hot rod, modifiers and car clubs.
If you need more info, the conference is due for Feb 17th at eastern creek raceway

Inaugural Motor Enthusiast Conference Report (http://4wdnow.com/index.php?option=com_content&view=article&id=39:inaugural-motor-enthusiast-conference-report&catid=11:latest-news&Itemid=3)