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Technical King Pin fitment in drop axle 30 Model A

Discussion in 'Traditional Hot Rods' started by Paul F, Sep 6, 2018.

  1. Paul F
    Joined: Dec 30, 2017
    Posts: 74

    Paul F

    Should this be a super tight fit, or do I need to home it out?

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  2. bct
    Joined: Apr 4, 2005
    Posts: 3,099


    need to be reamed . 13/16"
    Paul F likes this.
  3. Paul F
    Joined: Dec 30, 2017
    Posts: 74

    Paul F

    Thank you, it’s a so cal speedway 4” drop axle

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  4. bct
    Joined: Apr 4, 2005
    Posts: 3,099


    cool. its best to have a machine shop take care of it for you. the bore needs to be perfectly inline and true.

  5. WillH
    Joined: Dec 8, 2010
    Posts: 16

    from Texas

    Both the spindle bushing bores and axle bores need to be a snug slip fit.
    Paul F likes this.
  6. If you are asking about the fit in the axle itself, as your title suggests, it should be a nice tight fit on a new axle. A light "tap" fit is OK. Is there any paint, coatings, or even light rust in the bores, if so, it should be sanded out. If it still doesn't feel right, try your new pins from the top and bottom on both ends and see what's what. It would seem odd if both sides of the axle were out of spec; but who knows where and how the new axle was machined.
  7. Paul F
    Joined: Dec 30, 2017
    Posts: 74

    Paul F

    So cal speed shop

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  8. oj
    Joined: Jul 27, 2008
    Posts: 6,270


    Did you get the pins from So Cal as well? If 'yes' then the pin should slide smoothly in and out from either end and it'll be obvious that it is precise machined fit, no slop, nothing. If it is tight in the bore then the locating pin that locks it in place won't be able to seat right.
  9. Manager
    Joined: Mar 22, 2014
    Posts: 239


    I recently assembled a front end with a new So Cal axle and it surprised me how tight a fit the king pins were. As someone said they are usually a nice slide in fit. They did go in with light tapping after a good clean out.
  10. The pin should fit in the axle and fall in under its own weight with out force help or any excessive slop, the lock pin takes over from there and forces it to the side of the bore. You don't want it to walk around, click or wiggle but it shouldn't need force.
    In the spindle it should fit tight enough that it's own weight isn't enough to let it fall thru. Two thumbs pressure to push it in and the same to push it back up. Maybe 3 thumbs.

    Should not need hammers,
    oj likes this.
  11. 40Vert
    Joined: Jun 10, 2006
    Posts: 615


    I’ve had the same problem with my So Cal axle. Had to send it back, as they had forgotten to finish machine the holes. No complaints from the customer service end, they were real good and even paid for the shipping both ways.

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  12. Cheapstreet duster
    Joined: Jan 17, 2008
    Posts: 258

    Cheapstreet duster
    from georgia

    so how tight do you tighten the swedge pin nuts.. on the king pins..
    how tight do they need to be?
  13. AngleDrive
    Joined: Mar 9, 2006
    Posts: 985

    from Florida

    Beat them in with a brass hammer, then torque nuts to 25 ft/lbs.
    RICH B likes this.
  14. Atwater Mike
    Joined: May 31, 2002
    Posts: 10,707

    Atwater Mike

    A jerk machinist here in Atwater looked in the book, then reamed my first spindle on the Sunnen machine to 'specs'. The minute he handed it to me, the new pin was 'sloppy'...
    Dumb shit said, "Ah weunt accordin to th' BOOK..." I paid him $10.00 for the one, should have thumped his melon.
    An old gent sold me 20 king pin bushings for $30, (N.O.S.) so I'll ream them myself, by hand, with my good old WILSON Ford king pin reamer. Grrrrr.....
  15. krylon32
    Joined: Jan 29, 2006
    Posts: 7,513

    Alliance Vendor
    from Nebraska

    I've used and sold dozens of So-Cal axles with no kingpin problems, just a light coat of white grease and they slipped right in. More recently I had one for a personal project and the king pin would just start on one side and I didn't want to force it so I had to use a brake hone for a few minutes in that side to get a slip fit. On the other side the fit was great
  16. lostone
    Joined: Oct 13, 2013
    Posts: 1,795

    from kansas

    ^^^^^ you would think that as much as their axles cost you shouldn't need to do anything but put it together. Quality control is becoming a thing of the past.

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