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Dearching leaf springs?

Discussion in 'Engine and Drivetrain/Mechanical' started by miketyler, May 16, 2011.

  1. miketyler

    miketyler Member

    I need to drop the rear of my 70 at least three inches. Rather than putting the drop blocks under the car, was considering dearching. I called a spring shop today and they said they can do it. What do I need to know before I make a decision on this? I was reading that Rick Flores is running the 17x11 TTII wheel with the 315/35-17 tires. He said he had his springs dearched 3" and then had a 1" drop blck installed to get the ride height shown below.

    So tell me about dearching. Does it leave the spring strength intact or ? Any reasons why I shouldn't dearch?


    [​IMG]
     
  2. AzPete

    AzPete Well-Known Member Staff Member Moderator

    Instead of that, there is a way to de-arch them using another set of old springs and placing them between your leaves and upside down. Cannot find the old post but it is described somewhere on this place.....

    My experience with de-arching was never good...always uneven side to side.
     
  3. Grabber70Mach

    Grabber70Mach Well-Known Member

    This?

    http://www.stangnet.com/mustang-forums/ ... -long.html
     
  4. AzPete

    AzPete Well-Known Member Staff Member Moderator

  5. Grabber70Mach

    Grabber70Mach Well-Known Member

    Your welcome, glad to help.
     
  6. miketyler

    miketyler Member

    Thanks, I have read Latamuds article a few times on this. It seems like a little more work not to mention coming up with a second set of springs. Still good info but I was more interested in dearching and the experiences people had with the this type modification.
     
  7. buening

    buening Active Member

    No direct experience with de-arching, but take a peek at Opentrackers reply on #38 of the above Latamud link. You can basically shorten your leafs to get a drop, but this also reduces your spring rate and makes things a bit softer. What did the spring place quote you for the dearch?
     
  8. miketyler

    miketyler Member

    $50-$75 depending on if they have to replace a leaf. No heating involved, he said they do it using a cryo method. I need to get more details
     
  9. buening

    buening Active Member

    Wow I expected much worse. Is that for both springs? I think that'd be the way to go. You may check with them to see how it affects your spring rate.
     
  10. miketyler

    miketyler Member

    I need to call them back and confirm pricing on single or in pairs. One place I called cautioned against dearching 3+ inches stating it displaces the axle moving it back and out of center with wheelwell as well as nearly removing most of the upward spring travel. I found Rick Flores number yesterday, am going to call him and see if he can give me some details on how he did his dropped cars.
     
  11. miketyler

    miketyler Member

    Talked to Rick briefly as he was out or heading out of the country. He had his springs de-arched 2.5". So I took my springs off this weekend and plan to get them done this week as I want to start the car in two weeks.

    I called one other spring shop and described my application and the guy there told me dearching springs that much isn't good. He told me that it reduces the amount of shackle swing inviting bump stop incidents and displaces the wheel out of center of the wheel well opening. Also, he wanted $100-$125 per spring to dearch.

    Have any of you dearched and seen these things he describes?
     
  12. buening

    buening Active Member

    Mike are you using stock springs or reverse eyes? I'd recommend starting with reverse eye springs and then determine how much you need to drop the car. What that shop said makes sense, as you are essentially lengthening the spring. Since the front is fixed, the rear shackle must move backwards due to the lengthening. Since it is lengthened, you are pushing the axle further back since the front point is fixed.

    Take a string from one end of the spring to the other end and measure the distance from the string to the top of spring at the axle location. De-arching 2.5" may result in a near flat spring, or will become flat or reverse curvature during suspension travel. I have a feeling this is what he is talking about with the shackle swing, as when the spring is nearly flat the shackles don't move. The reverse eyes basically flip the eye at the front of the spring, building in an automatic drop compared to new standard springs.
     
  13. Midlife

    Midlife Well-Known Member Staff Member Moderator

    Re-arching the springs will run you about $100-$150. For just a few bucks more, you can buy reverse eye or correct arched springs new without the problems mentioned above.
     
  14. miketyler

    miketyler Member

    Am using stock springs and they have lots of spring to them. What is the real drop on reverse eye springs? I guess it can vary depending on what you started with but I need to get this rear where its going to be so I can get on with this build. Maybe Latamuds inverted spring addition is something to consider. He didnt mention anything about that in the article that I recall?
     
  15. buening

    buening Active Member

    Yeah it pretty much depends on what springs you currently have. If they are a 5 leaf with a higher spring rate, you'll get more of a drop with reverse eyes compared to a standard 4 leaf. Supposedly it will lower 1.5" over stock. Ideally you could use the reverse eyes and run a 1" lowering block to get you to your 2.5" drop. I'm running fairly new standard 4 leafs on mine and here is where it sits without any mods to the leafs or drop blocks (for reference):

    [​IMG]
     
    Last edited by a moderator: Jul 28, 2014
  16. miketyler

    miketyler Member

    Talked to Rick again today on both points. De-arching stock springs on his 69 pro touring car did not offset his wheel in center of wheel well, nor did it create any increased bump stop issues. He drove his car like this on the street and strip.

    I figure these are stock springs and if it turns out to be wrong, I can always buy reverse eyes.
     
  17. miketyler

    miketyler Member

    Got the springs dearched and I think I have it where I want it. I still have interior and fuel tank out. I bounced the heck out of the car and coudn't get it to bottom out. That might change with a full tank of gas. New rear ride height is right at 24 1/4. I took the wheels off the Cuda to test fit with. They are 17x11 with 7" backspacing. I may go with a different tire to add breathing room on the leafspring and wheel lip.
     

    Attached Files:

  18. miketyler

    miketyler Member

    another
     

    Attached Files:

  19. Fst Blk

    Fst Blk Well-Known Member

    I like that.
    Bill
     
  20. Grabber70Mach

    Grabber70Mach Well-Known Member

    Really like it. :thu :thu :thu :wor I think you nailed it. :pbj
     

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