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Coil suspension from a YJ?

Discussion in 'HardCore Corner' started by SPRDAV, Sep 15, 2003.

  1. SPRDAV

    SPRDAV

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    Has anyone had any luck adapting a Black Diamond coil suspension, built for a YJ (or TJ, I get them mixed up), to a Landcruiser FJ-40? I think it could be done with some modifications to the kit. Give me some input.
     
  2. CruisinGA

    CruisinGA

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    It would be a TJ, YJ's had leafs I believe.
    Gumby did a coilover on his 40 using 80 series coils. That sounds like the ticket to me. You could always use OME lift springs once you got OEM's to work. I'll let Gumby describe it himself, as it is his truck. :D
     
  3. Gumby

    Gumby Supamod Staff Member s-Moderator

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    Yup. Pretty gravy conversion all the way around. Needs some hard to find parts though. Lots of previous posts where I've gone on and on about it. You could probably find 'em with the search feature.
     
  4. woody

    woody Internet Fireman Staff Member

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    The Warn Coil conversion kit is what yer thinking of....YJ/CJ7 kit I believe. IMO, for that money, you can get a custom suspension done that will perform much better and be specific for your vechile. That kit was nice for what it was, but was tuned for "every" application, not your specifically.

    http://www.badlandsoffroad.com did Mike Smythe's coilover suspension (the baby blue that rotates thru the ih8mud.com main page). VERY nicely done.

    I'm in the early stages of my rear 4-link setup....hope to swing the $$$ parts late in October and get 'er built up. And yes, a full article is pending.... :D
     
  5. SPRDAV

    SPRDAV

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    You guys are probably right about a custom suspension system, but I have built everything on my cruiser, and for once I wanted to order a kit and weld it on. I probably shouldn't have bought the best 4x4 in the world then........The Chevota Landcrusier. Oh well, I'll begin the calculations then. What's the skinny on height and length of the four link suspension? I've heard that your top links should be 70% of your bottom links, in length, and your height from bottom link to top link depends on tire size (at the axle). I run 35's now, but I'm going to go to 39.5 on the next set. Ends and round stock are not a problem, I can buy that from a local race shop. Fill me in on the dimensions........

    Thanks in advance, Superdave
     
  6. woody

    woody Internet Fireman Staff Member

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    Mine will be:

    35" links, upper and lower
    triangulated upper, slightly splayed lowers
    5/8" hole 3/4" thread heims
    uppers are 1-3/8" OD .250 wall DOM
    lowers are same, then sleeved with .120 wall 1-1/2" DOM
    1/4 elliptical springs are the plan right now

    There isn't a lot of fab room in a SWB rig...I've taken a LOT of measurements, read a LOT of writeups, and sat down with a few people I consider experts....figger in some adjustability, and go for it!
     
  7. Slowerthanu

    Slowerthanu SILVER Star

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    woody, are you pushing your rearend back any further???



    As for the Warn Kit, build your own and do a TON of research (pic Woody's brain). The main disadvantage I see with the "Bolt-on" Coil kits is that they give you six or more inches of lift and a super flexy suspension but they dont address stability issues by increasing the Wheelbase.
     
  8. woody

    woody Internet Fireman Staff Member

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    [quote author=Slowerthanu link=board=12;threadid=5298;start=msg42019#msg42019 date=1063784106]
    woody, are you pushing your rearend back any further???
    [/quote]

    currently, I'm at a 96" wheelbase...rear axle is 3.5" back, front is 2.5" forward. I intend at least another 1" back in the rear with the links, perhaps 2". Just have to see how things align.
     
  9. SPRDAV

    SPRDAV

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    Woody, why are you choosing 1/4 elip instead of coil springs? What has your research shown? Thank you for the dimensions, it gives me a place to start. How far along are you in the build up........any pics?
     
  10. woody

    woody Internet Fireman Staff Member

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    http://www.ih8mud.com/tech/4-link.html

    Further than that, but not much...lol Might get more pics tonight...

    I've been a firm believer in not mixing-matching suspension styles....ie: if you run coils front, ya outta run them in the rear too. The 1/4 elliptical suspension is the closest to "matching" a front spring over. IMO, it will provide a balanced and controlled setup, unlike some suspension where one end or the other appears to do most of the work, or where one end comes into play well ahead of the other. If you look at Smythe's suspension, it's VERY balanced with the coilovers all around...that would be much more difficult if he kept SOA packs in the front.

    IMO again, coil springs take some adjustment, and most people are going to simply use what's available and compromise. The rates are fixed, not like a leaf where you can add/subtract to change the rate settings.

    And, it's what I had laying around and had time to play with. Makes the price right too :D

    My only concern at this point is the fixed-mounting location of the 1/4 ellip packs...until I have the existing suspension/hangers removed, I'm not positive my idea of locating them outside the frame rails will work...plan B is to recess them into the frame.
     
  11. Mace

    Mace rock scientist.. Staff Member s-Moderator

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    [quote author=woody link=board=12;threadid=5298;start=msg42192#msg42192 date=1063823602]
    http://www.ih8mud.com/tech/4-link.html

    Further than that, but not much...lol Might get more pics tonight...

    I've been a firm believer in not mixing-matching suspension styles....ie: if you run coils front, ya outta run them in the rear too. The 1/4 elliptical suspension is the closest to "matching" a front spring over. [/quote]

    Aww come on..
    You can't believe that a 1/4 eliptical is anywhere close to a SO just because it uses leaves to suspend it..
     
  12. cruiserrg

    cruiserrg

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    [quote author=Jason_M link=board=12;threadid=5298;start=msg43098#msg43098 date=1064011425]
    Aww come on..
    You can't believe that a 1/4 eliptical is anywhere close to a SO just because it uses leaves to suspend it.. [/quote]

    I agree, but I think he is saying its closer than a coil suspension. I think the 1/4 elip will react very different than the SO front and if looking for a balanced suspension, it is going to be hard to achieve with 1/4 rear SOA front. Especially considering that you are only using half the spring and usually inverted therefore reacting in the opposite direction as the front springs. Not to say an unbalanced suspension is bad, just if thats what you are trying to achieve it will be easier to 1/4 elip both ends. :D