KK lift

[bjeffers83]

Lift springs have a higher compression rate than stock springs so they have less squish. This could lead to different lift heights from springs that have similar unloaded lengths. But I don’t know why you didn’t get the height you expected. Maybe they sent the wrong springs?

Yes if the OME are 11.8 and the stock off the car are 11.3, that's around half an inch taller, and since I am only getting 1 inch of total lift, the OME only have half an inch less squish? That can't be right?

Hopefully someone with KK experience and memory or pics can chime in on if they noticed the OME were around the same/barely taller as I saw, or that thiers were obviously taller. I would like to know if I have the wrong springs on my hands or not and go from there. Those pictures, measurements, charts, and numbers are there for someone to confirm or deny what I am seeing here compared to their experience. To get 2.5 inches, I would expect to see like an inch or more in free height, and/or an inch or more in squish.

 

[JeepinJarhead03]

"how is that possible" = due to the coil rate, the only realistic way to test the coil rate on the bench, is to either build a jig to press the springs ontop of a scale and compress them about two inches or so to get the initial coil variance out of the way, then tare the scale, then compress them as close to an inch deflection as possible, and the measurement on the scale will be pretty close to what the coil rate is in lbs per inch. There's actual spring test equipment for this measurement, if you have a scale that will go to 800lbs (load about 400lbs before tare) then it's possible to build a test jig, if there's a race shop near you somewhere, they'd probably throw a spring on their tester for you for free. It sounds like you've done your due diligence in terms of on vehicle testing (hub to flare measurement) unless you've got significant weight in the cargo area, it looks like either mislabeled springs or out of spec springs, what I'd do is contact OME , give them your findings, and they'll send you a new set of rear springs. Other than the inconvenience of a reinstall, shouldn't cost you anything, they usually won't even ask for the incorrect springs to be sent back, about all they'll ask for is the origin of the purchase which is for QC tracking purposes. Be sure to detail what the expectation was, the service person may be able to come up with an alternative coil , cross platform, that will work for the intended goal - may be 3" instead of 2.5 etc. I've only lifted 15 or so KK, I've used 731s a little more than half the time, unless the loadout was heavier for one reason or another, The 731 has usually been pretty close to 2.25-2.5, when the loadouts were heavy, an extra iso usually trimmed it out back to the goal, or load assist spring shocks for the extra height or load control. If it's a pretty standard loadout in terms of no real aftermarket addon stuff weight, and the springs aren't measuring on vehicle where they're supposed to be, I'd skip right to contacting OME

 

[soewhatman]

"how is that possible" = due to the coil rate, the only realistic way to test the coil rate on the bench, is to either build a jig to press the springs ontop of a scale and compress them about two inches or so to get the initial coil variance out of the way, then tare the scale, then compress them as close to an inch deflection as possible, and the measurement on the scale will be pretty close to what the coil rate is in lbs per inch. There's actual spring test equipment for this measurement, if you have a scale that will go to 800lbs (load about 400lbs before tare) then it's possible to build a test jig, if there's a race shop near you somewhere, they'd probably throw a spring on their tester for you for free. It sounds like you've done your due diligence in terms of on vehicle testing (hub to flare measurement) unless you've got significant weight in the cargo area, it looks like either mislabeled springs or out of spec springs, what I'd do is contact OME , give them your findings, and they'll send you a new set of rear springs. Other than the inconvenience of a reinstall, shouldn't cost you anything, they usually won't even ask for the incorrect springs to be sent back, about all they'll ask for is the origin of the purchase which is for QC tracking purposes. Be sure to detail what the expectation was, the service person may be able to come up with an alternative coil , cross platform, that will work for the intended goal - may be 3" instead of 2.5 etc. I've only lifted 15 or so KK, I've used 731s a little more than half the time, unless the loadout was heavier for one reason or another, The 731 has usually been pretty close to 2.25-2.5, when the loadouts were heavy, an extra iso usually trimmed it out back to the goal, or load assist spring shocks for the extra height or load control. If it's a pretty standard loadout in terms of no real aftermarket addon stuff weight, and the springs aren't measuring on vehicle where they're supposed to be, I'd skip right to contacting OME

I had an issue with OME front springs for my KJ and they were very good about sending replacements once I sent them a few photos and a copy of receipt. I believe mine were either mislabeled or improperly manufactured, and getting very little lift over stock height. It does happen.

 

[JeepinJarhead03]

I had an issue with OME front springs for my KJ and they were very good about sending replacements once I sent them a few photos and a copy of receipt. I believe mine were either mislabeled or improperly manufactured, and getting very little lift over stock height. It does happen.

With the front, I think it was a label printer that was printing 924 that looked like a 927 or something like that, I got sent a set of those and just happened to still have a coil spring tester in the shop at the time and noticed it preinstall, well not even preinstall , the guys vehicle wasn't due in for 2wks yet, it got sorted with no time lost

 

[tommudd]

Jeepinjarhead has done more KKs than I have , ( only done 9 for me) but over 60 KJs )
but since I seem not to make you understand that springs can and will be the same height but give lift I'll let jarhead finish helping you
maybe I wrote it out un Swahili LOL

 

[bjeffers83]

"how is that possible" = due to the coil rate, the only realistic way to test the coil rate on the bench, is to either build a jig to press the springs ontop of a scale and compress them about two inches or so to get the initial coil variance out of the way, then tare the scale, then compress them as close to an inch deflection as possible, and the measurement on the scale will be pretty close to what the coil rate is in lbs per inch. There's actual spring test equipment for this measurement, if you have a scale that will go to 800lbs (load about 400lbs before tare) then it's possible to build a test jig, if there's a race shop near you somewhere, they'd probably throw a spring on their tester for you for free. It sounds like you've done your due diligence in terms of on vehicle testing (hub to flare measurement) unless you've got significant weight in the cargo area, it looks like either mislabeled springs or out of spec springs, what I'd do is contact OME , give them your findings, and they'll send you a new set of rear springs. Other than the inconvenience of a reinstall, shouldn't cost you anything, they usually won't even ask for the incorrect springs to be sent back, about all they'll ask for is the origin of the purchase which is for QC tracking purposes. Be sure to detail what the expectation was, the service person may be able to come up with an alternative coil , cross platform, that will work for the intended goal - may be 3" instead of 2.5 etc. I've only lifted 15 or so KK, I've used 731s a little more than half the time, unless the loadout was heavier for one reason or another, The 731 has usually been pretty close to 2.25-2.5, when the loadouts were heavy, an extra iso usually trimmed it out back to the goal, or load assist spring shocks for the extra height or load control. If it's a pretty standard loadout in terms of no real aftermarket addon stuff weight, and the springs aren't measuring on vehicle where they're supposed to be, I'd skip right to contacting OME

Via email with arb usa

I have attached our Liberty KK guide. It states that the 2731 springs will provide approximately 1.5'' of lift for the rear. I'm not sure where it said 2.5'' but that is not correct.

That's all I got out of them.

After driving a few days, I measure about 20.5 in the rear now, which is 1.5 over stock, which is what they are "supposed" to be, idk why it's not more. When you were measuring that 2.25-2.5, what was the hub to fender measurement? I had basically 0 sag, so maybe that's where the extra inch went?

 

[JeepinJarhead03]

ARBs 1.5" measurement, basically across the board, on springs labeled 1.5" , are AU insurance regulation certed springs , this includes , 2926, 2927, 2790 2947 and 2948 in addition to the KK springs 2731** . ** Is a footnote I'll come back to, all of those springs are listed as 1.5" for au ins purposes - they're not allowed to sell higher than that in au - with specific loadouts (which are very rarely ever the actual loadout) or the springs intended loadout, 1.5 is what you'd get, 2927 is basically used as a gasser 3" , loadout wise is basically a crd 1.5, 2790 gasser +winch for 3, is technically a crd +winch and massive bullbar and probably a few kangaroos on the hood for 1.5, the 2948 , I guess would need a 6000lb caravan on it to be 1.5 but from what I understand, that's how they shimmyed it through au regs. 2731**note - the last time I used 2731 they measured on the vehicle with no cargo, no extra isos and the vehicle slightly nose high, like 2.25" - I don't remember but I may have mentioned that in the previous post. It's been awhile, and when I did that lift, I have no way of knowing how long the springs had sat on the shelf, they may have been there a year or three, or may have just came off of a international flight and had been manufactured the month prior, I have no way of knowing. ARB may have changed the spring from like 2.25 to 1.5 - when they do that though, they typically create a new part number. It's simple enough to trim in additional lift - but more in line with your initial reaction, had I installed them and they measured 1.5" instead of 2.25+, I'd have been calling ARB - and if they stuck to "oh they're supposed to be 1.5", I guess I would have had to accept that , at least on the surface, and my follow up question, would have been, well , do you have a spring that is the same or close to the same diameter, with the same coil rate and longer free length, or something along that line, and attempted to find an alternative coil that would result in 2.5 or whatever the goal was - it may not have resulted in a find, it's easier to go to 4, 6, etc in alternative coils, than it is 1.5 to 2.5, but it's also possible to chop a longer coil that's an appropriate rate and use it as a lower lift too, so that would have been my next step if necessary.

 

[JeepinJarhead03]

In terms of the KK hub to flare measurement, on the show room floor, at least until early 2011, they were 18F/19R stock- the last sub 4+ I have on the books, was leveled at 21.5/21.35 shimmed the front clevis 1/4" , I didn't record any rear extra isos, don't remember adding any, not that it isn't possible anyway, but that would have been a result of 3.5" front 2.35" rear