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View Full Version : JK shorty lift advice



Dru
03-09-14, 12:06 PM
The question of whether or not we needed to lift a Rubicon was well and truly answered in the Wattagans bog holes. :highly_amused: I don't think I want to go mild, but I'm not building a comp truck either.

So, with a move to 35"s and 3.5" lift, I would normally do this in one hit, but cost and practicality tell me otherwise. Is there a method that can be done in stages? I don't have a garage so generally will need things done by a mechanic. How have you guys gone about it? What would you do differently?

Ideally I still want to go wheelin at each stage. Tire and wheels would be last. How does this effect geometries etc when the lift is designed for 35's but sitting on 32's for a while?

I've been doing a lot of reading, just it's a bit daunting when you are about to hit the "start" button.

Steve F
03-09-14, 01:06 PM
There will be no issues running 32's on a lift for 35's other than the look ;) My XJ is running around on 31's at the moment but it's normal tyres are 35's.

My JK Rubicon (also a shorty) has just been lifted about 2.5", the main reason for me was to get the belly up, it still runs the stock tyres while the bank balance builds up and I wear them out. In all honesty a rubi with a small lift and muddies is pretty unstoppable, my ultimate plan is to keep the lift on this one lower, run a 33 or maybe 34 and limit flex to help keep it stable off camber. With the twin lockers, good ramp over (after a lift) and the short overhangs at either end I find it doesn't need the same amount of mods as the XJ did to go the same places and it will happily crawl through while cocking one tyre (or more) in the air. On a travel ramp my XJ will give it a kicking but in the real world I think they will be hard to seperate.

The advantage with this, we'll legality, street-ability, easy for my wife to drive it and keeps the costs right down :)

Cheers
Steve

Dru
03-09-14, 01:54 PM
Cheers Steve.

My thoughts were that with 2.5" and 33's I really want a bit of width in the tires to make up for reduced road contact with MUDs compared to ATs. From recollection the widest that will fit stock rims is 11.5". More than this means new wheels as well as tires.

New wheels and tires for 33's is going to be roughly the same cost as for 35's. I suspect it's the biggest cost here and if committed to it why not do 35's? I'd hate to work a 2.5 inch lift and get hung on my next trail. Pretty much means starting again doesn't it?

The street legal thing is confusing and hard to get clear answers. In reality how often are Jeepers hassled? While 35's will be a higher risk I hear of 33's getting pulled up too. I wonder how much this is about drawing attention to yourself?

I know common sense and street ability dictates 33". Tough decision!

Steve F
03-09-14, 02:06 PM
The hassling is getting more common, is it a daily driver? If you think you need the lift to run the trails you want to run then do it, I found with the XJ most of the challenge had gone out of the trails as it would drive most everything quite easily :) In saying that, with suspension and tyres the sills have gone up 8"

As an aside a good mud tyre will not be noticeably different on the road to an AT, at least grip wise. The KM2's I run on the XJ are great on the road :)

Cheers
Steve

Paul-JK
03-09-14, 04:56 PM
You can easily fit 35's under a JK with a 2.5" lift.
Keeps the lift lower to limit the extra parts you need for the lift and keeps the centre of gravity lower.
You'll need new wheels for 35's as the stock wheels are only supposed to be used for tyres up to about 33". If you did try to run 35's on them then you'd need wheel spacers.
You will then need to add something to cover the tyres as they'll be sticking out a fair bit. Getting aftermarket replacement guards will then free up fair bit of space to allow the 35's to come much further up under flex.

DLE068
04-09-14, 07:16 PM
If u get the right wheels with back space close to stock u won't need aftermarket guards. Just takes a bit of research

Paul-JK
04-09-14, 08:55 PM
True, but keeping the stock guards with 35's and a minimal (2.5") lift will likely mean reducing the up travel to stop the tyres hitting the guards.
Getting new guards will open up the options on new wheels as you can go a bit wider (which will also help stability which can only be a good thing on a shorty) and will give you maximum flex rather than having to limit the axle movement to keep the tyres off the guards.
Either will work, just depends on budget and intended use.

Dru
04-10-14, 11:29 AM
Has someone here been through the legals properly?

I was running over what seemed to be the relevant ADRs. Up to 50mm increase in ride height is exempt. So a 2" lift with 33" tyres is not legal without relevant certification. Unless I am missing something.

Certification (my term for the purpose of the discussion) then makes it legal up to 150mm. That way a 3.5" lift with 35's, by my thumb print, is OK. With certification.

By certification what I mean is there is a design cert under the ADR that is required. Surely the decent kits have this available? And then the installer certifies under the ADR. All good.

Then to NSW administration of the ADR, and it needs inspection and sign off. I presume this is what is meant when Jeepers say "engineering".

The other thing, is that looking through the ADR it is all commonsense stuff. Geometries, brake lines, suspension travel, no DWs etc. which surely we want anyway?

What am I missing?

We have checked with our insurers who are cool as long as it is legal. Everything seems fine so far.

AV8
04-10-14, 09:26 PM
Hi Dru,

I think you have it right. Mind you, you may not be legal QLD after being certified here in NSW.A trip to the Cape might be a worry then.

I don't think that there is a kit as such that will fit the ADR requirement and it is your choice to fit the appropriate one to meet the requirement of your state.

Having said that, how would you know what the new lift is if you change axles, mounting brackets, flares, sliders, etc. Where is the new datum where lift height is measured from?


Steve F, if you don't mind me asking,

Which engineer did you use for your XJ?
Is it certified for the 35s?
Whats your overall lift? <150mm?
Did you have to do a lane change test?
How much did it cost?

Steve F
04-10-14, 09:36 PM
Mine isn't certified, wolfe got his done but not with 35s. No chance of getting an xj done on 35s when 28 is stock

AV8
04-10-14, 11:01 PM
Thanks Steve. My bad. I thought I had read somewhere that it was certified. Cool

Paul-JK
05-10-14, 07:20 AM
I had heard that Jeep Konnection were selling some lifts that were engineered, i.e. your car will be engineered with them. Might have been the AEV lifts but I'm not sure.
Might be worth giving them a ring.
It would probably mean a trip to Melbourne to get it fitted and I'd make sure it's engineered for NSW and not just VIC.

Dru
05-10-14, 03:17 PM
"Where is the new datum?"

I'm no lawyer nor a techie, but if I'm reading it right, you would start with the "tallest" version of your car from the manufacturer that already has ADR design compliance. For the JK that would be the Ruby with 17" wheels and (roughly) 32" tyres.

Then measure it at the roof, before and after. So half the tyre size increase + the lift. Over and above the Ruby.

I know now what you mean about different states. We brought my Porsche 928 back from the UK and had it certified in BrisVegus. Then had to do it all over again when we moved to NSW. I think you would be ok though as long as it was legal and certified and registered in your home state. If you were just using an address of convenience you might be in trouble.

Wooders
07-10-14, 08:18 AM
I had heard that Jeep Konnection were selling some lifts that were engineered, i.e. your car will be engineered with them. Might have been the AEV lifts but I'm not sure.
Might be worth giving them a ring.
It would probably mean a trip to Melbourne to get it fitted and I'd make sure it's engineered for NSW and not just VIC.

Engineering Approval is a state specific process to certify that the vehiole is deemed safe under the ADRs and that states laws.
For a national approval the vehicle would need to be passed as an entire configuration (inc wheels/tyres/bumpers etc) and run through the entire testing process which would likely include crash testing etc. Then every vehicle would have to be setup thew same. The cost would be substantial and I don't think it would return on the investment.
I Could be wrong by that's my understanding and perspective.

AV8
07-10-14, 11:04 AM
"Where is the new datum?"

I'm no lawyer nor a techie, but if I'm reading it right, you would start with the "tallest" version of your car from the manufacturer that already has ADR design compliance. For the JK that would be the Ruby with 17" wheels and (roughly) 32" tyres.

Then measure it at the roof, before and after. So half the tyre size increase + the lift. Over and above the Ruby...

Sure mate, that's easily understood. I suppose it is easy to compare semi stock vehicles.

What if changes were made for example, different sized axles, axle mounting bracket height/angle, new body mounting bracket, higher wider fender flares, rock rails height, soft top vs hard top. Just by changing the axles alone changes the start point where one needs to measure and compare heights/distance from.

We're all bush lawyers here, why not spend some dough and get a definitive answer from straight the horse... ;) The engineers.

Recc: Andrew Treeve, Rob Elliott, Rob Fletcher

Not Recc: Terry Toomey, Ian Carpenter

here is the lis (http://www.rms.nsw.gov.au/documents/business-industry/examiners/vsccs-bulletin-01-licensed-certifiers.pdf)t (http://www.rms.nsw.gov.au/documents/business-industry/examiners/vsccs-bulletin-01-licensed-certifiers.pdf)

Dru
08-10-14, 06:17 PM
The ADR for suspension mods covers all your specifics. Is this this topic somehow inappropriate?

I have indeed been speaking to the engineers, on the whole the response is not overwhelming. I had hoped for guidance here before approaching the certifiers.

Btw I tried to add copies of (what I think are the relevant) ADRs and the NSW certifications requirements in this thread, but do not have the right privileges to do photos or make attachments.

Steve F
08-10-14, 08:34 PM
Nobody can add attachments at the moment due to some technical issues, try using photo bucket and adding a link

Cheers
Steve

Heidi
08-10-14, 09:23 PM
i think the amount of wheel travel at stock also comes into play so technically you may be able to go more than a 2" lift

Dru
14-10-14, 11:38 PM
Hi guys. Thanks for all the input. I did get a heads up in PM as to why this might be a sensitive topic. Honest, I had no idea.

sorry to anyone I have annoyed.

Steve F
15-10-14, 08:40 AM
Wouldn't worry about annoying anyone, can't see how you could have, or why it might be a sensitive topic, don't hesitate to ask questions that's what the forum is for :)

Cheers
Steve

AV8
15-10-14, 01:41 PM
Hi guys. Thanks for all the input. I did get a heads up in PM as to why this might be a sensitive topic. Honest, I had no idea.

sorry to anyone I have annoyed.

Yeah, why would it be a sensitive topic. I don't get it. Lift, ADR, Engineering = Physics, Law, Aesthetics, Clearance, Comfort

Hmmmmm.... could I also please be PM'd for explanation of the above?

Cheers

stevet
15-10-14, 10:38 PM
Hi guys. Thanks for all the input. I did get a heads up in PM as to why this might be a sensitive topic. Honest, I had no idea.

sorry to anyone I have annoyed.
No annoyance to me....:smile-new:...... Please keep the info coming.....:smile-new:........ Need answers for the TJ's lift, etc when the time comes down the line( bloody long line presently...:grumpy:...), so I can hopefully pick some good, knowledgeable input from folks better informed then me to use/learn a wee-bit more on the topic......:smile-new:........

Dru
17-10-14, 08:33 PM
I should say that the PMs I received were greatly welcomed and not even slightly negative. Just explaining stuff and I appreciate it.

OK stevet I'll run over where I ended up. There is a specific ADR for suspension lifts. It also covers a lot of other things not as relevant. It's a logical document that covers things that we would all want handled in a lift. You can lift a car to match anything the manufacturer has done with the model. Beyond this you have 50mm grace. But this includes tyres as well as the lift. After this, with paper work you can go to a max 150mm. Which would cover 35's with lift on a JK. The paperwork is a) for design, which I have had the temerity to suggest should be sorted by the importer or manufacturer. b) then the installer does paperwork to say he did it to the designers intention.

Easy so far. Then you need to deal with local state certification. Which should be easy with that paperwork.

there are two flaws to my thinking. 1/ you can also only increase the track by 25mm. And most kits cover handling in a lift by increasing track by more than this. So my "easy" doesn't actually work. 2/ the manufacturers and importers don't do this paperwork, so you have to do full engineering as you don't have the design cert.

i was quoted $3,500 for the cert/engineering. That buys a lot of toys for the Jeep.

think that covers it.

AV8
30-11-14, 11:10 AM
After this, with paper work you can go to a max 150mm. Which would cover 35's with lift on a JK.

Hi Dru,

This is true for stock axles = 150mm max lift (Body/Suspension/Tyres).

for non stock axles, the max lift is 1200mm to the top of your headlights. This may be more than 150mm to the original stock axles.

If you'd like to take it up to 35", get the 2.5"-3.0" lift done, tyres and wheels, flares, mud guards, steering and what not and go see Rob Fletcher from offtrack4x4.com in Unanderra. Top bloke and charges less than half of what you were quoted. Rob was recommended to me by Jose BTW. :single_eye:

Dru
30-11-14, 06:19 PM
Cheers bloke.

lift etc happens this week. Exciting stuff.