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63" springs????

Discussion in 'The Garage' started by sapper, May 29, 2002.

  1. sapper

    sapper 1/2 ton status GMOTM Winner

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    63\" springs????

    thinking about putting these on (orders the ORD flip today/forums/images/icons/smile.gif what trucks should i look for in a bone yard and heres the dumb question how do you measure them? is it the entire length of the spring or straight from eye to eye? thanks
     
  2. Triaged

    Triaged 1/2 ton status

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    Re: 63\" springs????

    I could get you some measurments Thurs...I have a pair sitting outside. They came in 88- 1/2-ton p/u's (IFS).
    The center pin is centered (or close to it) just like the 52" springs. This means that you will have to move your front spring hanger forward 5.5" (or what I am going to do...move the front spring hanger forward 4.5" to have the axle moved back 1"). The back is no problem because you have to remove the factory hanger. I have thought about using another shackle flip bracket as the front spring hanger but I'm going to try and make the factory bracket work first to keep the cost down.

    I have heard that you shoulden't flip the overload on the 63" springs...they will flex plenty without flipping it. You can also take a look at the ORD Blazer...it has 63" leaves.
     
  3. Triaged

    Triaged 1/2 ton status

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  4. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Re: 63\" springs????

    Dan,

    What's the spring rate (Lbs-In) on those 63 inchers? Any idea? Same ride height as stock K5 springs? I've got the 4" shackle flip so I only need to know if I'm still gonna get 4" of lift or if I'll need zero rates too....

    My fronts are VERY soft, and I don't know if I should be trying to match that rate or simply avoid EXACT multiples of that front rate to prevent weird oscillations (I'm just guessing here....I'm thinking resonances or "harmonic" type issues, but I don't know if that applies to a damped spring the same way it applies in other conditions?)
     
  5. sapper

    sapper 1/2 ton status GMOTM Winner

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    Re: 63\" springs????

    tahnks. the plan was to mobve the rear axle around 3 inches to the rear something like Stephens blazer. anybody do this any thing to make it not work??
     
  6. Boss

    Boss 1/2 ton status Author

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    Re: 63\" springs????

    I didn't use 63" leaves but, I moved my rear axle back 3". There is room to spare. I wouldn't move it back any further though.
    Boss
     
  7. sapper

    sapper 1/2 ton status GMOTM Winner

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    Re: 63\" springs????

    wouldnt the axle not being centered on the spring cause a problem?
     
  8. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Re: 63\" springs????

    Sapper,

    I know from talking to Dr. Watson that a long spring with a pin substantially off towards one side doesn't buy you as much flex as you might hope for. The "short side" of the spring becomes the limiting factor on how much flex you get.

    So I guess in a perfect world.......get a LONG spring with a CENTERED pin, then work like crazy to get the brackets to work!!! /forums/images/icons/cool.gif
     
  9. sapper

    sapper 1/2 ton status GMOTM Winner

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    Re: 63\" springs????

    Hey Greg that is what i'm looking for, bunches of flex. I prolly should of asked more questions in the first post. Anyway guess i'll be going out to some bone yards this weekends and start trying to figure it out. Anymore suggestions would be great. Heres one more for the road though. The link that was posted was around toyotas and they looked for two wheel drive springs, but since our rigs wiegh about three times that much i will need the 4x4 right?
     
  10. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Re: 63\" springs????

    Only problem with long springs (especially symmetrical) is, you can't do much to improve your departure angle. With the short side back, combined with the Springer drop arm, I get the benefits of a super long spring without the rear over hang required for something like the 63" GMs. Also, longer springs (just like my reversed spring) will have more axle wrap tendencies.
     
  11. Chris Demartini

    Chris Demartini 1/2 ton status

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    Re: 63\" springs????

    <font color=blue>Triaged, if I moved my front hanger 4.5" foward, how far back would I have to move the rear hanger (which would be cut to flip the shackle)?
     
  12. Triaged

    Triaged 1/2 ton status

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    Re: 63\" springs????

    I am not worried too much about departure angle. The shackle flip bracket can be swapped side to side (moving the top of the shackle back around 3") and the rest must be made up by moving the brackets back and drilling more holes. If you are looking at moving the axle back 1" the top of the shackle will have to be moved back about 3.5" more. The springs will stick out a bit past the gas tank but not below it. On a 71 frame you would be able to cut off about 2" if you really wanted to. On a 72 you could cut more because they have a real frame horn that goes all the way to the bumper (ie 71 and older blazers have a short frame already). I haven't bothered to calculate the spring rate yet because they are still in pieces (I need to buy some new center pins...what do you want for free?)....its still light out give me a while and I might get you some spring rate ###'s. I would guess they are stout enough to hold up a 1st gen (lighter then a 2nd gen) because of how heavy a IFS truck is....BRB.
     
  13. eldon519

    eldon519 1/2 ton status

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    Re: 63\" springs????

    Will the 63" inch springs not bolt to the stock spring hangers? I know they will have to be moved farther apart but would it still not bolt up after that?
     
  14. Chris Demartini

    Chris Demartini 1/2 ton status

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    Re: 63\" springs????

    <font color=blue>As far as I know the springs are the same width, that's what you mean right?

    The reason I ask about the rear hanger is because the previous owner actually cut the back few inches off the frame /forums/images/icons/shocked.gif to install some bumper for something other than a Chevy. I made a new section of frame out of 1/8" plate. It's strong but I don't think I would want to mount a spring hanger to it. It's kinda hard to explain, here's a pic <a target="_blank" href=http://community.webshots.com/photo/25499947/27052430UxtLLcPlBA>http://community.webshots.com/photo/25499947/27052430UxtLLcPlBA</a>. From the way it sounds, I should have enough room back there
     
  15. Triaged

    Triaged 1/2 ton status

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    Re: 63\" springs????

    I don't think that has been cut off! That is how mine is and it was stock. I think pre 72 blazers had a frame like that and is was only in 72 that the frame was longer...something to discuss in the 1st gen board.
     
  16. Triaged

    Triaged 1/2 ton status

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    Re: 63\" springs????

    # of leaves = 3
    Free Length (eye-to-eye) = 61.5"
    Spring Length (along main spring) = 64"
    Free Arch (from a line between the eyes to the top of the main leaf) = 7.88"
    Leaf thickness = .375"
    Spring Rate = 148(lbf/in) ****Damn thats low!****
    Center pin to front eye = 32"
    Center pin to rear eye = 32"
    2nd leaf length = 52"
    3rd leaf length = 43"
     
  17. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Re: 63\" springs????

    Dan,

    YIKES! 148 Lbs-in is low all right!!!

    Those must be the 2WD versions I guess huh? That Pirate thread seemed to indcate that the 4WD ones had 4 leaves so the rate should be a bit higher.

    I guess the proof is in the pudding. I'll be curious to see how it looks when it's done, and certainly how it drives and flexes too! /forums/images/icons/cool.gif
     
  18. Triaged

    Triaged 1/2 ton status

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    Re: 63\" springs????

    Just for some compairson:

    Rancho #86211 (pre-runner 2.5" lift rear springs 52" length) are 230 (lbf/in)
    Rancho #86209 (2.5" lift rear springs, 52" length) are 290 (lbf/in)
    Rancho #41054S (4" lift 1st gen front springs, 43.57" length) are 720 (lbf/in) ****I had no idea they were that stiff...maybe it isn't the shocks after all!****

    If my claculations are correct the 4 leaf 63" springs are around 190 (lbf/in) which seams more what they should be...I might have to find some of them.

    I'll try and get some ##'s up for the stock 52" rear springs.
    Does anyone have a set laying around to measure the free arch?
     
  19. Chris Demartini

    Chris Demartini 1/2 ton status

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    Re: 63\" springs????

    <font color=blue>Damn my Ranchos suck but I had no idea they were 720 lbs/inch!!! /forums/images/icons/shocked.gif No wonder I get more frame twist than flex! Anyone running 52" rear springs on the front of a 1st gen? I know of a set of 52s from a 90 K5 that I could probably get for free and the local boneyard wants $100 for a pair of 63s.
     
  20. Triaged

    Triaged 1/2 ton status

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    Re: 63\" springs????

    No kidding!...no wonder my back hurts the day after I go wheel'n! Maybe I should worry about softening up the front before I mess w/ the rear? It might handle weard with springs 4 times softer in the rear than the front?

    I don't know about trying 52" leaves in the front...but I am thinking of using some 73- front springs, only moving the front hanger, and using a longer shackle. It should end up with a nice shackle angle and the 73- springs have alot more options (not to mention cheeper).
     

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