Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Leaf spring center pin

Discussion in 'The Garage' started by lochenjons, Apr 16, 2007.

  1. lochenjons

    lochenjons 1/2 ton status

    Joined:
    Sep 13, 2006
    Posts:
    682
    Likes Received:
    0
    Location:
    Santa Cruz, CA
    So after taking my old axle out I realized one of the center pins was broken (who knows how long that was broken:rolleyes:), sheered off inside the lift block with nothing sticking out from under the spring pack. So I take the old pin out and get a grade 8 bolt for the new center pin and pound the grade 8 bolt thru. The bolt is bigger than the old center pin, but not by much. But enough that its taking awhile to pound it through the sping pack. Now I realize, once I'm almost done, that I don't have it going through the top leaf (the head is on the top). And I'm like !@#$%@ :mad:. The head was going to serve the same purpose as the nut on the old center pin, I'm not sure if this is how your "supposed to do this" but it seems to make sense. Anyway, my question is, Can I just grind or cut off the head of the bolt and put the first leaf on top? So basically it would be the same thing as not having a bolt on top of the center pin. I cant imagine what could happen since the ubolts hold it down and the thing (cant remember the name :mad:) the ubolts go thru that goes on top of the spring pack will make sure the bolt doesnt come out (and believe me it wouldnt be coming out anytime soon anyways with how hard its pounded in). I also have to redrill a hole in the block where the bottom of the center pin was. Anything rediculously unsafe about this? Either way I figure it's safer than it was with it broken :D
     
  2. k20

    k20 3/4 ton status

    Joined:
    Sep 9, 2001
    Posts:
    5,068
    Likes Received:
    0
    Location:
    Mineral Springs, NC
    Well the center pin holds the pack together. The way you should have done is ground the head of the bolt round, so it would fit in the hole on the axle, pounded it through, put a nut on the end of it, then slid it down and u-bolted it. I dont really forsee any way that you could have failure as is, but maybe Im not thinking it all the way through
     
  3. lochenjons

    lochenjons 1/2 ton status

    Joined:
    Sep 13, 2006
    Posts:
    682
    Likes Received:
    0
    Location:
    Santa Cruz, CA
    Yeah but I didnt have a grinder right then and I figured it would all be the same thing. The only other size bolt that was smaller than what I got would have been way too small...so no easy sliding it thru the leaf pack
     
  4. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,060
    Likes Received:
    69
    Location:
    Pleasanton, CA.
    The center pins are there for a reason (to locate the axle in the correct position). You can buy the center pins new at just about every auto parts store. If you can't find them then i suggest you use an allen bolt, it has the correct size round head and are grade 8. You need to remove the bolt you've put in and correct it.

    The bolts are 3/8" x 16 TPI (Threads Per Inch)
     
  5. BlazerBud

    BlazerBud 1/2 ton status

    Joined:
    Jun 14, 2006
    Posts:
    473
    Likes Received:
    0
    Location:
    Chattanooga
    Take the advice, your thrust angle will get off if the axle slips up on the leaf spring, and you'll be so out of whack you can't drive straight. Your Chevy will look like a Ford coming down the road sideways.............Before anyone gets mad, my tow rig is a Ford.
     
  6. lochenjons

    lochenjons 1/2 ton status

    Joined:
    Sep 13, 2006
    Posts:
    682
    Likes Received:
    0
    Location:
    Santa Cruz, CA
    How would it be able to slip up on the leaf spring? I always thought the center pin was to keep the leaf pack centered on the axle and keep the leaf springs from coming out all over the place or slipping around. The bolt should be able to do all that and the ubolts should do everything the nut on the center pin would have done and then some. For sure its not ideal or anything, but all I've got around here for autoparts stores are autozone and kragens and I doubt they've even heard of a center pin
     
  7. k20

    k20 3/4 ton status

    Joined:
    Sep 9, 2001
    Posts:
    5,068
    Likes Received:
    0
    Location:
    Mineral Springs, NC
    Yeh, it will keep it centered assume the bolt is tight in the hole on the axle. I didnt think about it, but the bolt diameter in the leaf springs is a fair bit smaller than that hole on the axle.
     
  8. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,060
    Likes Received:
    69
    Location:
    Pleasanton, CA.
    autozone will have the center pins. Hell, we carry them at my store. they are like 5.00 each or something. They are 12" long and you cut to your desired length.
     
  9. lochenjons

    lochenjons 1/2 ton status

    Joined:
    Sep 13, 2006
    Posts:
    682
    Likes Received:
    0
    Location:
    Santa Cruz, CA
    Ok I just realized what would normally be a problem. I have blocks and the center pin is bigger at that part that goes in to the blocks. So normally there'd be a gap where the block could move a little. But since I have to redrill a hole in the center pin thats in the block anyways, Ill make it the right size.
     
  10. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,060
    Likes Received:
    69
    Location:
    Pleasanton, CA.
    You can buy center pins with different diameter heads on them but with the correct size bolt thread.
     
  11. lochenjons

    lochenjons 1/2 ton status

    Joined:
    Sep 13, 2006
    Posts:
    682
    Likes Received:
    0
    Location:
    Santa Cruz, CA
    I gave up trying to pound the bigger size bolt through (once it gets past the threads the diameter is slightly bigger which made it impossible). So it took it out (that was fun) and decided to try autozone and kragens and see if I could find the center pin

    At autozone, at least one of the people kinda knew what it was even though at first they tried giving me wheel studs. He didnt know where they were though and after talking to someone else he decided they didn't ahve them. So I go down the street to kragens which usually is worse, and they don't even know what a center pin is. They kept trying to give me ubolts, and even with 5 employees all giving me a blank confused stare they couldnt figure it out. So I got an allen bolt from ace hardware, and I've given up drilling through the top of the block so Ill take that to my metalshop at school and drill it, I'll probably have to cut the top of the bolt but other than that everything should work
     
  12. barneybasher1010

    barneybasher1010 1/2 ton status

    Joined:
    Sep 25, 2005
    Posts:
    908
    Likes Received:
    0
    Location:
    PORTERVILLE CA
    The auto zone and kragens did not have it here either. Kragens knew what is was but auto zone did not.
     
  13. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,060
    Likes Received:
    69
    Location:
    Pleasanton, CA.
    The blocks are made with the locating pin on the "top" as cast with the rest of the block, the hole in the bottom, well it's just a hole in the block. If the "top" locating pin is broken the block is junk. I'm guessing by saying the "top" you actually mean the side that mounts against the axle spring pad?
     
  14. lochenjons

    lochenjons 1/2 ton status

    Joined:
    Sep 13, 2006
    Posts:
    682
    Likes Received:
    0
    Location:
    Santa Cruz, CA
    The locating pin is on the bottom (goes "inside" the spring perch). The hole is on the top of the block and the center pin that goes through the spring pack goes into the hole just as it would normally go into the spring perch hole without the blocks. right? Thats how all lift blocks I've seen are, cant imagine it being any different

    EDIT: and no the locating pin isnt broken, the center pin broke inside the block
     
  15. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,060
    Likes Received:
    69
    Location:
    Pleasanton, CA.
    That's what i wanted to make sure you were talking about. So just drill out the broken center pin from the block and if you need to i can get you a price on center pins from work tomorrow. You just need to measure the diameter of the head of the pin, the thread portion should be 3/8".
     
  16. lochenjons

    lochenjons 1/2 ton status

    Joined:
    Sep 13, 2006
    Posts:
    682
    Likes Received:
    0
    Location:
    Santa Cruz, CA
    Its ok if the bolt is slightly smaller than the hole right? I have a 3/8 bolt and its slides right through the spring pack, but 7/16 wont fit through, even with a lot of work.
     
  17. Avery4jc

    Avery4jc 1 ton status Premium Member GMOTM Winner

    Joined:
    Oct 24, 2005
    Posts:
    10,760
    Likes Received:
    75
    Location:
    Fresno, Ca.

Share This Page