WJ Legal 17" Rim and Tire Options

[Gojeep]

Originally Posted by junglejuice

20's would be illegal at least here in QLD as you can only go up by 2" on the largest that was fitted.
As for tyres sizes and lift sizes here in QLD it is a pain, 15mm is the maximum for tyres but lifts gets very vague as there is no "2" maximum allowed" as it gets down to wheel travel increase and decrease so if you have 100mm downtravel from rest you can only lift the vehicle by 1/3 of that so 33mm.
As for widths yes we can go up by 1.5 times stock but if it fouls on the steering you aren't allowed to adjust steering stops to compensate plus the tyres cannot stick out past the flares.

As for getting pulled over, that isn't the major issue, if you have a crash and someone is hurt or worse and your car has oversized (illegal) tyres then it is unroadworthy and you are in a whole world of trouble (jail)....

I thought he would be alright being a WH and they offered 20" rims standard factory fitted on the SRT? Little confusing as he did post this on the WJ thread which never had that rim size.

[v8_jofes]

Thought I'd post these links and info in here regarding tyre sizes.
I realise the following national code of practice hasn't been adopted in Qld yet, I don't know about other states and couldn't find a definite source that would tell me where it has been adopted.

According to section LS of the National Code of Practice for Light Vehicle Construction and Modification http://www.infrastructure.gov.au/roa.../vsb_ncop.aspx if your car is considered to be an Off Road Passenger Vehicle (vehicle category MC) you can fit tyres to your car that are not more than 50mm larger (in Diameter) than that of any tyre designated by the vehicle manufacturer for that vehicle.

To determine if your car is an MC class vehicle: (Taken from http://www.comlaw.gov.au/Details/F20...#_Toc326158540 ) (and WJ info taken from http://www.wjjeeps.com/dimensions.htm )

4.3.3. OFF-ROAD PASSENGER VEHICLE (MC)

A passenger vehicle having up to 9 seating positions, including that of the driver and being designed with special features for off-road operation. A vehicle with special features for off-road operation is a vehicle that:

(a) Unless otherwise ‘Approved‘ has 4 wheel drive; and

(b) has at least 4 of the following 5 characteristics calculated when the vehicle is at its ‘Unladen Mass‘ on a level surface, with the front wheels parallel to the vehicle’s longitudinal centreline, and the tyres inflated to the ‘Manufacturer‘s’ recommended pressure:

(i) ‘Approach Angle‘ of not less than 28 degrees; (WJ = 36.7)

(ii) ‘Breakover Angle‘ of not less than 14 degrees; (WJ = 22.6)

(iii) ‘Departure Angle‘ of not less than 20 degrees; (WJ = 28.6)

(iv) ‘Running Clearance‘ of not less than 200 mm; (WJ least clearance is 220.8mm at transfer case cover)

(v) ‘Front Axle Clearance‘, ‘Rear Axle Clearance‘ or ‘Suspension Clearance‘ of not less than 175 mm each. (WJ = 231.14mm)

For those of us in Qld, we're stuck in the 90's with http://www.tmr.qld.gov.au/Safety/Veh...fications.aspx in which, I can't even find a suspension modification section??

There's some other interesting stuff in the NCOP regarding lifts under 50mm, and those between 50-150mm etc etc

/end research.

[fester]

It's not all beer and skittles though as that 50mm of tyre increase gets included in the overall lift calculation. So if you have 50mm lift in tyres you get nothing in suspension unless you go the whole engineering route. Also there is no requirement at this stage for any of the states to adopt the code and they can adopt it in full or part and still modify it so we could still get screwed if thye pick certain bits out.

Qld does have a suspension ruling it is that you can increase your height as long you you don't increase your bump stop travel by more than 1/3rd of it's original travel. So if you have 100mm of bump stop travel you can lift 33mm.

[SeaComms]

Its actually alter bump stop by more than 1/3 from memory so does this mean if you lift, put longer shocks and a small extension to the bump stops you should be ok??

Also a 50mm larger diameter tyre is only a 25mm increase in height in theory and prob less in practice.

Sent from Tapatalk as I finally ditched the Windows 7.5 heap of rubbish

[fester]

Originally Posted by SeaComms

Its actually alter bump stop by more than 1/3 from memory so does this mean if you lift, put longer shocks and a small extension to the bump stops you should be ok??

Also a 50mm larger diameter tyre is only a 25mm increase in height in theory and prob less in practice.

Sent from Tapatalk as I finally ditched the Windows 7.5 heap of rubbish

I don't believe you can alter the original bump stops, you can only increase the standard bump stop travel based on the standard components. Otherwise you could lift the truck as high as you like as long as you space the bump stops and Qld Tpt is not that dumb.

Tyre detail is correct if it is worde that way, I thought they were saying a 50mm lift increase was allowed in the tyre eg from a 31 to a 35 with the proviso that that then allowed no further increase in suspension etc. In effect if that was the case it would be self limiting.

[broadz]

updated Victorian Standards are located here: http://www.vicroads.vic.gov.au/NR/rd...orvehicles.pdf

[Chumby]

Nice set if rims with legal offset:

http://www.jeep4x4center.com/america...978050430.html

Cheers
Chumby