If you are a newbie reading this forum, thinking about lifting your KJ - here are a few things I've learned while researching and having a lift fitted to my Diesel 05 KJ:-
1) Manufacturers of spring lifts quote their lift figures based on the platform they used to engineer the lift - either a pre-lowered 02 model or a lowered 03 (3/4inch lower). Jeep lowered the 03's 20mm in response to a Magazine tester that rolled a KJ while pushing it HARD through a witches hat course. They seem to be creeping up again in height though now.....read on and you will see.
2) No one can give a measurement that tells you what height each of these base platforms actually sits stock (as far as I can see).
3) Wheel arch to lower rim (using stock 16inch rims) is a common measurement to use as a reference but so far very few people and no manufactuers quote these measurements either stock or after their lifts
4) Your car may sit lower or higher relative to the base platforms when it is straight from the factory (there's 10 or more different springs used in KJ's)
5) If fitting a SPRING lift (replacing stock springs) - the lift you end up with on the front may not be the full amount quoted by the manufactuer or it may be more, you will get the quoted lift relative to the KJ the manufacturer tested on, which may have been lower or higher than yours. So don't automatically assume your car will be lifted 2.5inches if you fit a 2.5inch lift!
6) If fitting a SPACER lift with your current springs, then you will get the quoted lift of the manufacturer within 10mm generally, as you are just adding to what you already have.
7) Ask people posting about their spring lifts what their final arch to lower rim measurements (with 16 inch wheels) are - as these are the most useful way of comparing where your car will sit once lifted with the same spring lift they used
8.) From the reasearch I've done, a lowered 03 sits around 680mm at the arch to rim measurement stock, and a pre-lowered closer to 700mm, and a lifted KJ shouldn't exceed 750mm otherwise CV problems could occur. My CRD sat at 710mm stock (above the pre-lowered height).
9) One of the best spring lifts for PETROL KJ's that gives a reasonable lift within safe limits seems to be the OME spring lift with 927's on the front and 947's or 948's on the rear. This should net 740mm front and 750mm rear measurements after the lift with OME struts, 10mm less on the front if you use Rancho struts, as the clevis mounting point is at a different spot than on the OME's. Given this, I reckon the OME's are probably best used if you are doing an OME spring lift. The mounting point on the Rancho's is the same as on the stock struts. These measurements are with an ARB bar.
10) The best lift for the current 2.8L diesel at the moment (especially if you fit an ARB bar), because of its extra weight is to use the original front springs, plus either the Daystar 1.5inch (Part Number KJ09119) or 2.5 inch (Part Number KJ09117) spacer lift on the front (use the one that is going to give you around 740mm after lift compared to your car stock with your springs). eg. My KJ was 710mm stock and I'm fitting the 1.5inch kit next week which should bring it up to 740mm.
11) On the rear use OME 947 or 948 springs (edit - I'd recommend 948 only if you are towing a boat or caravan regularly, because the 947's are plenty stiff enough for use without a trailer even when fully loaded, they work fine on mine). Its recommended that you change the front struts to Rancho or OME when you add the spacer lift, as the stock struts don't have as much travel and could 'top out' and destroy themselves when at full extension. Rancho make the RSX17505 and RSX17004 that fit a lifted KJ. The RSX17004 is a longer shock for the rear than anything else available on the market (50mm longer than stock - its for a Dodge SUV available in the USA), and is recommended for max travel on the rear of the KJ. Rancho shocks are less expensive than the OME's. The RSX17505's are available in Australia, but you will need to get the RSX17004's freighted in from the USA - but they are still cheaper than the OME's even with the freight! James at JeepersandCreepers.com can supply them.
12) If you use OME springs on the front of a diesel (927 is the only one nearly heavy enough for the front), then expect 20mm less lift than the same spring on a petrol model because of the extra weight of the diesel engine, and a spongy ride! (The OME spring really isn't suitable for the 2.8CRD's, especially if you fit an ARB bar (mine sagged back to the stock height without the ARB bar after a week) - maybe ok for the earlier 2.5CRD - Suburban run them on their 2.5L Diesel KJ).
13) OME (Old Man Emu) is available from ARB stockists, Daystar spacers are available from James at
http://www.jeepersandcreepers.com or
james@jeepersandcreepers.com (USA based - fast, cheap freight) the Daystar web site is here so you can get part numbers -
http://www.daystarproducts.com/html/...kits/index.htm
14) Rocky Road
http://www.rocky-road.com also can supply Daystar spacers and have their own strut top plates that provide about 20mm of lift if you need that bit more! Rusty's off road
http://www.rustysoffroad.com also have some strut top plates that should give about 1/2 an inch more lift, but some guys on the USA forums have reported fitment problems as the holes didn't line up perfectly - nothing that a bigger drill wouldn't fix though. James at JeepersandCreepers can supply these too.
16) If you lift your car over 3 inches then expect that you may get some driveline vibration (not to mention damaged CV joints on the front at some point and ball joint problems). The fix for the driveline vibration is to lower the transfer case by putting shims under the mount points. USA4x4 in Melbourne has done this for one KJ owner I believe.
17) After having tried both the OME and Rancho front Struts on my 2.8CRD - I can say the OME struts work much better with the heavy weight of the CRD. If you use the Ranchos you will find you can bottom out the front suspension fairly easily because they don't control the compression of the spring as well. The Ranchos would be ok on a Petrol KJ though - as they are a lot less weighty in the front end! This is backed up by the Liberty owners in the USA - they use a lot of Rancho over there.
18.) At the present time, the rear shocks by Rancho (RSX17004) are the only longer option available that will allow the suspension utilise the maximum spring extension it has available. The standard OME ones are only slightly longer than the stock ones. However, CRDSTU has been testing an OME shock from another model of vehicle that are longer than the Ranchos and all reports so far have been good. Information is going to be released soon about these or PM CRD STU.
19) Its been a few months since I posted this and other guys have tried some combos. I believe this combination to give a good lift (at least 2 inches), well within suspension limits without the need to shim the tranny case:-
Front
Diesel 2.8L CRD
without Bar - OME HD STRUT, Custom "CRDSTU" King Springs
Diesel 2.8L CRD with ARB Bar - OME HD Strut, Stock Springs, Daystar 1.5 inch Spacer, Rocky Road Strut top plate
OR
Diesel 2.8L CRD with ARB Bar - OME HD Strut, Custome "CRDSTU" King Springs, Rocky Road Strut top plate
Petrol with/without ARB Bar - OME or Rancho Strut, OME Springs (choose the correct one)
Rear
All - Rancho RSX 17004 Shocks or new N132L OME Shock with ARB springs MD or HD Springs - use HD if towing. You can also add a 10mm TJ rear spring spacer to give a little extra lift. Use the Daystar 35mm rear bumpstops with the N132L springs.
*Update 19/12/06* CRDSTU has worked with King Springs in QLD to produce a front spring specific for the CRD KJ that will give at least two inches of lift. Check out the information in the other sticky thread - this is probably the best front spring for the CRD KJ now as you don't need to use a Daystar spacer, although, my set-up is still working really well on and off-road.
*Update 26/03/07* OME now have N132L (L for Long) rear shocks for the KJ that are about 1.5 inches longer than there original N132 rear shocks for the KJ. Should be available in Australia by April 2007. You need to install a Daystar rear bump stop with these shocks to prevent them over compressing. OME are also working on a new 500lb front spring for the CRD KJ which is soon to be released. These will be heavier than the 465lb spring CRDSTU had custom made by Kings Springs in the paragraph above. As yet the OME ones are untested as no one has them yet.
Hope this info helps save some of you the pain I went through! Oh yeah - the KJ Cherokee is called a 'Liberty' in the USA!