How to measure for rear springs?

Anyone have a simple, down and dirty way to measure to determine how much lift I have so I can order the right spring? Front is adjustable thanks to the ACOS but the rear is needing love. Currently it has shackle relocation brackets with jks shackles, bastardized stock springs and ?? Leafs, and I added a set of cheap 2" blocks to get the height right for mock up. Now that its time... How do I determine what lift height springs I need so the blocks can go away but the height stays??

What's the coils 3 or 4.5 or? You need to somewhat match what you have in the front, what's bets is a combo of spring and a lift shackle to give you a better ride

Shackles will held most any spring ride better

jeepdreamer said:

Anyone have a simple, down and dirty way to measure to determine how much lift I have so I can order the right spring? Front is adjustable thanks to the ACOS but the rear is needing love. Currently it has shackle relocation brackets with jks shackles, bastardized stock springs and ?? Leafs, and I added a set of cheap 2" blocks to get the height right for mock up. Now that its time... How do I determine what lift height springs I need so the blocks can go away but the height stays??

Click to expand...

Measuring lift.
http://www.naxja.org/forum/showthread.php?t=26622&highlight=measuring+lift

First determine what lift you have now.
Buying springs according it's rated lift is a crapshoot due to manufacture variations and the variations in the weight of the Jeep.
Most spring give more than the rated lift (sometime a LOT more) and then collapse over the next year or so.

Over the last 12 years, I have gone through several sets of manufactured springs plus a couple sets of home-brew springs.
Last year I installed a set of BDS 3" leafs and they are the first that did not cave in after a few months.
Newly installed, they gave 3-1/2" and almost immediately settled down to the rated 3", where they still sit.
http://bds-suspension.com/product-display?ma=7&mo=29&yr=2001
They are my new favorite spring.....until i can afford some Deavers.

Thanks guys... great info lazyxj. I'm probably on about 4"s lift? Hard to say really but I agree. Most spring manufacturer's seem to under rate the initial lift and bank on it settling.
I run BDS on my scrambler and may have to look into them. To bad OME doesn't offer bigger lifts...they are great quality and way less than deaver. I'll have to look through my records on what size springs I ordered for the front. Add in the adjusted ACOS height and I should be close.

My experience.. The spring rates on the Old Man Emu CSO33rb are on the firm-sporty side (matched with the OME sport shocks). The jeep rides firm, but not harsh. It corners precisely on dirt and street. Lift amount has not sagged at all after over a year - 4.25 inches. The 1997 jeep XJ handles a load of camping gear and remains very stable and predictable.

Well... a local guy had a pair of brand new rustys 4.5" springs that weren't going to work out on his jeepster commando so I scooped em up. Hopefully they are enough for the correct height. I'm running shackle relocation brackets and jks shackles but can't remember if those give any lift as well... Guess I'll find out this weekend when I slap em in. I couldn't find a spring rate on rustys site so hopefully they don't ride like a dump truck. If they are to soft when I load the gear I can always find a way install my airbags.

So I got the springs in yesterday and it looks pretty close to the height I was at with the bastard packs without running the stupid blocks. Yea!
But I have a couple questions. The jeep seems to lean to the passenger side some now which may just be the springs needing to find their home. But looking at the jks shackles I see they look like they will contact the shackle relocation brackets when the spring compresses. Anyone else able to look at this pic and tell me if I need to think about cutting the relocation bracket or go with a different shackle?
Then I have a second issue. I scored these airride airbags off craigslist and thought maybe they'd be a cool way to keep the heep level when it's all loaded with expedition gear. I don't plan on rock crawling while stocked with expo gear but I'm curious how the bags will handle it when one side of the axle drops out during flex. Anyone have any ideas? *just have the bags and brackets sitting in there for visual. *

Your shackles are backwards...

notamos said:

Your shackles are backwards...

Click to expand...

X2 curve toward the front for extra clearance on compression.


As far as the bags are concerned. You will need to limit both compressiom and extention with bumpstops and limit straps. Over extending the bag will rip it. Over compressing could damage internally

Oh now that IS embarrassing! backwards. In an idiot.
Thanks guys. Ill fix that Saturday.
As for limiting travel... Yeah, that makes sense. In just not sure how much limiting to do.? Generally speaking the bags should act as bump stops by doing their job... Kinda. But the bigger concern is droop. I suppose limiting straps would do it but what I'm not able to wrap my head around is how it would allow any droop. Unlike the firestone two chambers in my dodge, these don't seem to have any room to extend. What am I missing?

The way they are installed now at ride height, they are practically fully extended. There job is mostly to load stabilize. So if the rear compresses because of a heavy load they stabilize and lift the rear back to normal ride height. (I know obvious right) the bad part of that and how they are currently installed on your rig, is there will be no droop from ride height.

There are some installs ive seen that let the bottom of the bag disconnect from the axle when drooping out. Not sure how to engineer that but it has been done.

It is kind of a conundrum and I don't get it. Even looked at the install manual but it doesn't really clarify much.
Manual here in case you want to give it a quick look and maybe see something I'm missing.?.
https://www.airliftcompany.com/support/manuals/?kit=59507

Learned something interesting with the bags today and think I'm on to a solution. Will post more tomorrow when I remember to take pics.

Pics as promised. Didn't realize that the bags did this. Obviously this is their max extention point and limiting straps will be used to keep them from getting this far but it helps me understand how to make them work... I hope.

Finally got the brackets finished and painted. Put it together today and it looks like it will work. Need some limiting straps and bump stops as well as shorter rear shocks. Also have to decide where to route the air lines and reroute the exhaust but I'm happy with it for now. Need to get back to the drawers as I'm running out of time before it all gets packed for my move to Colorado Springs.