KK 4" Rear Lift Springs (kind-of)

Discussion in 'Lift Kit Discussion' started by Hunter Toth, Apr 6, 2021.

  1. Hunter Toth

    Hunter Toth Member KJ Supporting Member

    Messages:
    45
    Likes Received:
    17
    Joined:
    Apr 18, 2019
    Hey guys,

    I figured it would be of use to someone to know that I have found a decent alternative for 4" rear springs since nobody advertises them anymore

    First off, gotta give OME credit. I had no idea they had an applications catalog with all their spring specs in it :D

    Here's a link to it, if the link ever dies let me know, I downloaded a copy.

    I put all these specs into Excel and was able to sort them all by free length and spring rate
    I was basing my filters on the OME 2731 springs, with 280 lbf/in rate, 11.811 free height (40mm lift)

    One thing they don't include in the catalog is the spring diameter, so it was important to watch out for small diameter springs for coilovers. I narrowed my results to only vehicles with solid axles

    The closest one was some Disco springs, OME 2767. They have 14.764in free length, 280 lbf/in. perfect! :D

    Well, I kind of took a shot in the dark and ordered a pair from Summit, thinking I could return them if they aren't what I expected.

    Very excited when they arrived
    Some measurements: Mine was closer to 15" free length, 4.645" inside diameter, 5.945" outside diameter.

    The biggest issue with this is the diameter is considerably larger than stock springs. So the isolators almost fit through the spring center

    After some more searching, I found that Energy Suspension's universal isolator (9.6108G) would fit pretty well. They don't have steel inside, they are just floppy polyurethane. This actually worked to my advantage, because with the stock isolators I would have had more than 4" lift

    I felt confident enough at that point so I threw them on

    [​IMG]

    [​IMG]


    For those of you who don't know of these issues I've been battling, first off, my Libbys got some hunk in the trunk

    I have a full steel rear bumper, with swingout tire carrier, filled jerry can, hi-lift, 32" spare
    not to mention 200+ lbs of tools I keep inside

    This is the original springs JBA sent me with the 4" lift package

    [​IMG]

    As you can see, travel is very limited. Yes, the lower bump stop is missing, that's how the shop that installed my lift installed it :mad:
    Also, this is without the steel bumper, jack, gas, spare (spare is in middle of the roof)

    I then tried to order custom springs with a stiffer rate for the new coming bumper

    [​IMG]

    These had even less travel, and it still sounded/felt terrible when compressing to max (with bumpstops)

    The new 2767s have been on now a few days and it's fantastic to drive. Haven't had the chance to get it offroad yet, but I will soon

    In my driveway with a full tank of gas and all my stuff, I'm sitting at just about 23" from hub center to flare


    Let me know what you guys think, and I hope this could help any of you looking for a similar solution
     
    lfhoward likes this.
  2. lfhoward

    lfhoward Full Access Member

    Messages:
    665
    Likes Received:
    432
    Joined:
    Dec 9, 2012
    Location:
    Philadelphia, PA
    Iā€™m still running my original 4ā€ JBA springs, and I tow regularly, so your research will come in handy for my Jeep at some point! My JBA springs are looking kind of crusty...

    [​IMG]

    They have a different coil pitch than yours do. I have an earlier version of the lift kit, from 2011 or so.
     
  3. Hunter Toth

    Hunter Toth Member KJ Supporting Member

    Messages:
    45
    Likes Received:
    17
    Joined:
    Apr 18, 2019
    Yes they do :p

    I wish I could find those. I don't understand why mine had such a fine coil pitch
     
    lfhoward likes this.
  4. tommudd

    tommudd Moderator Staff Member Moderator

    Messages:
    19,248
    Likes Received:
    1,016
    Joined:
    Jul 14, 2005
    Location:
    Southeastern Ohio
    Some have used them ( the ones you just bought ) on KJs for years now