How to not bind my CVs with SPC UCAs

Taylor Spaulding Jan 21, 2021

  1. Taylor Spaulding

    Taylor Spaulding Bought an X

    Messages:
    66
    Location:
    Vacaville, CA
    Hey all, this is probably a dumb question, but one I haven't seen answered or even discussed anywhere on this site or others. I'm likely just bad at googling.

    I have a 2013 S with SW bumper with winch, engine and rad skids, sliders, and rear bumper. I recently purchased the AllDogsOffroad 5100 Ultimate kit with 650# springs.I was thinking about putting them on the 0.5" clip for a full 3" of lift. I also purchased some SPC UCAs to avoid CBC....but realized that this is a potential booby trap and just asking for trouble without a bumpstop.

    Anyone that is running SPC UCAs (perhaps also on 5100s) do you do anything to ensure your CVs remain at a decent angle and keep from binding?
     
  2. TerryD

    TerryD Total Tease Supporting Member

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    3,214
    Location:
    Covington, Va
    Does your front setup include any kind of spacer? The 5100s are only about 1/4" longer than OE shocks so if you aren't running a spacer you don't have to worry so much about bind as you do a rough ride with almost no down travel from static ride height.
     
  3. Taylor Spaulding

    Taylor Spaulding Bought an X

    Messages:
    66
    Location:
    Vacaville, CA
    I was planning on running a 2.5" spacer. And where I'm most concerned is at full droop.
     
  4. TerryD

    TerryD Total Tease Supporting Member

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    3,214
    Location:
    Covington, Va
    The 2.5" spacer is gonna be binding the CVs and TREs at full droop. You'll start chewing through them.

    I run a 0.5" spacer on my Radflos and my lift is set at about 2.5".
     
  5. Taylor Spaulding

    Taylor Spaulding Bought an X

    Messages:
    66
    Location:
    Vacaville, CA
    Th
    Right, that was my understanding. I was wondering if anyone has tried to mitigate that by using straps? Or Maybe it would just be easier to get some bumpstops welded to the UCA...
     
  6. Taylor Spaulding

    Taylor Spaulding Bought an X

    Messages:
    66
    Location:
    Vacaville, CA
    @TerryD I'm wondering if we are talking around each other? You mentioned you have your Radflos set to 2.5" preload lift with a 0.5" spacer which should provide 3" of lift.

    I was planning to set my preload lift to 0.5" with a spacer of 2.5". From my reading, isn't this an optimal setup? Perhaps I'm way off here. I'm only looking to get 2-3" max of lift.
     
  7. IM1RU

    IM1RU Need Bigger Tires Supporting Member

    Messages:
    616
    Location:
    SLC, UT
    @Taylor Spaulding

    You can do a little pre work, and measuring and figure all this out on your own.

    Measure the center of the hub to the fender. Jack up the truck, now measure the center of the hub to fender again. That's your stock set up droop. For every inch you lift, you'll loose that same amount in droop. Write those numbers down.

    Now that your truck is jacked up, remove the wheel, and remover the shock. At this point you can measure the total possible wheel travel by measuring where is hangs , the jack it up until it binds on the compression. (i.e. from ball joint/ cv bind to ball joint bind or CBC to ball joint bind. ) I think you'll find that the droop number is dangerously close to the same number as when you had the shock in.

    By adding the SPC UCA you gain droop, but also bind the ball joint, not so much the CV. Which means on extension the thing that stops the wheel travel is either the ball joints CBC or the internal stops in the shocks, or a bump stop / limit straps if you have them.

    Think of your lift like this:

    The total length of the shock is a finite number dictated by the available space between mounting points. When you add a top spacer, you are increasing the overall length of the shock (and it will lift the truck but potentially cause CBC or bind). You cannot go past the total available space. The preload on the spring is what gives you the lift. If you have 650 lbs springs it takes 650lbs of force to compress that spring one inch, and another 650 for every additional inch, and the lifting happens because the preload is more resistance than the resting truck weights.

    None of this means much if you don't take the time to set up your suspension correctly, and no amount of discussion on the forum will solve the set up for you. So you need to measure, and adjust over and over until you get it right. The very least amount of droop you want remaining is 2 - 2.5 inches, and then you simply live with the amount of lift it gives you.
     
    TerryD likes this.
  8. Taylor Spaulding

    Taylor Spaulding Bought an X

    Messages:
    66
    Location:
    Vacaville, CA
    @IM1RU
    I think you mistook the point of this thread. I KNOW I have the potential to bind something. I'm wondering what people are doing to PREVENT the binding if they have SPC arms. Are they using limiter straps? Are they just wheeling carefully? do they just tear through their CVs/ball joint boots? The thread got derailed a bit regarding the lift "options".

    I am almost positive I have my setup correct. I'm not the first to run this setup by any means.
     
    Last edited: Jan 22, 2021
  9. IM1RU

    IM1RU Need Bigger Tires Supporting Member

    Messages:
    616
    Location:
    SLC, UT
    Limit straps or bump stops, is really the only way.

    As has been noted, it's either the ball joints or the TRE's that get trashed, not the CV's.

    I had replaced lower ball joints and TRE's before I t-swaped, now I run limit straps.

    Don't weld bump stops onto the SPC's. Get limit straps if you're concerned about it. My guess (without seeing your rig) is that you'll trash your shocks first.
     
  10. Taylor Spaulding

    Taylor Spaulding Bought an X

    Messages:
    66
    Location:
    Vacaville, CA
    Limit straps it is. I was leaning that way.
     
  11. TerryD

    TerryD Total Tease Supporting Member

    Messages:
    3,214
    Location:
    Covington, Va
    Unless you are damaging your shock due to constant bottoming out, just use appropriate height spacers and maintain your up travel.

    I've got about 40k miles on my Rads and ball joints without issue running the 0.5" thick spacer.
     
    Taylor Spaulding and IM1RU like this.
  12. IM1RU

    IM1RU Need Bigger Tires Supporting Member

    Messages:
    616
    Location:
    SLC, UT
    ^this
     

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