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centering pin relocation

Discussion in 'OffRoad Design' started by 79Beast, Mar 18, 2002.

  1. 79Beast

    79Beast 1/2 ton status

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    Alright, get the picture: '79 k10, 8" front springs, ORD shackles and crossover steering. Fender trimming to clear 44" swamper TSLs. I want to move my front axle forward for that last little bit of tire to tub clearance. I don't want to use zero rates because of the 1" lift associated with them. I don't want to have to mess with the rear to match the added height plus I am right on the money with headlight height vs. State of GA law. My idea is to relocate both of my centering pins forward between 1 and 2". Another added bonus will be a slight increase in front driveshaft length and approach angle (not a problem with 44's and a tight front bumper). There is not much anyone can say to make me decide not to go through with this. I'm really just looking for suggestions/ advice from anyone who has done this or thinks they know about it/ possible negative effects...etc. Let me know what ya'll think. Also, if having the axle centered front to rear on the leaf spring allows for more axle wrap than having it offset one way or the other, will this help my front axlewrap problem? The only time I have this problem is pulling another truck or something HEAVY while in 4wheel drive. I can snatch all day in 2 wheel drive without my truck jumping up and down.
     
  2. Stephen

    Stephen 1/2 ton status Moderator Vendor

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    Just drill a new hole in the spring perch for the center pin and put a new dimple in the ubolt plate.
     
  3. 79Beast

    79Beast 1/2 ton status

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    I don't understand the advantage to redrilling the spring perch vs. installing a new centering pin and then removing the old one. Why would I need to dimple the ubolt plate? If I move the pin, the axle and plate will still be in the same location relative to the centering pin. Am I missing something realy important?
     
  4. wayne

    wayne 3/4 ton status

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    I don't think a second hole in the spring pack is a good idea. That might create a weak point for the springs to break.
     
  5. Greg72

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

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    I think the top plate will stay in the same position (relative to the axle) due to the U-Bolts pulling it STRAIGHT down....

    I guess the way to think of it is that the spring pack isn't really moving at all.....but the axle and it's clamping parts DO. It's hard to explain, but I'll bet once you SEE it.....it will make sense. /forums/images/icons/smile.gif

    Maybe just weld up the extra hole in the spring pad, if there are concerns about strength too....??
     
  6. Stephen

    Stephen 1/2 ton status Moderator Vendor

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    I think we have 2 different lines of though here.
    One is drill the spring itself. I'm not so fond of this idea either, since it can be fairly hard to do and does create another weaker section in the spring. Technically speaking the ubolts clamp that area and make it inactive so it should never move and hence can't stress and break. But in the real world things go wrong like ubolts not being torqued all the time.
    Drilling the axle pad is pretty harmless. If you do that the ubolt plate stays centered over the axle and you'll have to have a new dimple for the head of the centerpin to sit in.
     
  7. 79Beast

    79Beast 1/2 ton status

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    right.....it's the whole new hole in the spring pad I don't understand. I plan to drill a new hole in my leafspring and install another centering pin forward of the old one. I will remove the original before putting the axle back under it. The new centering pin will ride in the factory hole in the spring pad. Thanks for you help. I always welcome opinions and ideas.
     
  8. 79Beast

    79Beast 1/2 ton status

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    I would be tempted to agree with you about two holes in the leaf, except that they will not be side by side, rather they will be front to back. With 1 1/2" of metal between them and a spring pad on top, I don't think strength will be an issue. The holes will not be in a part of the spring that flexes. Also, they are small holes and if small holes were that detrimental to spring strength, the manufacturer wouldn't have put them there to start with.
     
  9. 79Beast

    79Beast 1/2 ton status

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    I'm starting to see the light. I'm only talking 1-2", so it would probably be easier to just drill another hole in the spring pad. Does anyone know how far I can drill into the spring pad on the chunk side of my D60 safely? Would there be any issues for me to adress with less spring pad in front of the pin? What would this do to axlewrap? Oh yeah.....thanks for all the replies. Ya'll are awesome.
     
  10. Mr.Chevy4x4

    Mr.Chevy4x4 1/2 ton status

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    I can tell you that your spring pad is 1.5 inches off the top of the axle tube, so as long as you dont drill more than 1.5 inches deep you should be ok.

    Mike
     
  11. Stephen

    Stephen 1/2 ton status Moderator Vendor

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    I think a bulb just lit!
    You just need to drill 1/2" or so for the head of the pin. I don't think you're going to see much difference in performance, maybe a slight change in axle wrap, but I think you'd have to do the math on paper to find it. In the real world I think you're just going to have a longer front driveshaft, a bit more pinion down angle and more tire clearance at the back of the fender opening.
     
  12. 72THING

    72THING 1/2 ton status

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    Stephen, you're a genius. I never would have thought of that.

    Will
     
  13. Stephen

    Stephen 1/2 ton status Moderator Vendor

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    I won't let my head swell up over the idea of drilling the spring perches, but thanks anyway!
     

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