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Technical Dropped Axle

Discussion in 'Traditional Hot Rods' started by Deuce Man, Jun 1, 2020.

  1. Deuce Man
    Joined: Jul 31, 2015
    Posts: 199

    Deuce Man

    I want to put a dropped axle in my full fendered 29 pickup. It presently has what I think is a 37 axle, it is undropped and my 16 inch 40 ford tires and wheels rub my fenders when turning. My 29 full fendered roadster has a dropped axle and sits quite low yet never has any tire rub problems. can the axle drop guys duplicate what I have in my roadster width wise, or should I just try to order a new one that is close to what is in my roadster? If I decide to go with one of the axle drop guys, who do you guys recommend.? Also is it economical? or should I just buy one out of a catalog? Thanks guys Rich
     
  2. Jalopy Joker
    Joined: Sep 3, 2006
    Posts: 25,272

    Jalopy Joker
    Member

    post some pics of PU and roadster
     
  3. You should be able to get about whatever you want when it comes to drop and kingpin to kingpin width depending on what axle you start with. I highly recommend Nostalgia Sid's www.droppedaxles.com, but he is also a good friend and I could be biased...
     
    jimgoetz, Jibs and -Brent- like this.
  4. irishsteve
    Joined: Jan 10, 2017
    Posts: 828

    irishsteve

    Most dropped axles get narrower after the drop.New made can be had in several widths.If you buy new make sure its forged.
     

  5. Mr48chev
    Joined: Dec 28, 2007
    Posts: 27,520

    Mr48chev
    ALLIANCE MEMBER

    This chart from Sids shows the different measurements on the A through 48 Ford axles.
    https://www.droppedaxles.com/ford-dropped-axles-0
    A tape measure and a bit of eyeballing should confirm what axle you have under it now.
    I'd compare king pin center to king pin center between the two rigs you have sitting there while I had the tape out.

    Somewhere on another thread, two or three there has been discussion on which width of dripped axle works best for Full Fendered Model A's to get the tire centered right so it doesn't hit.
     
    lothiandon1940 likes this.
  6. Can’t help with the axle situation. But I want you to know your Roadster is in my Garage safe & sound. Let the fun continue. Later Lou


    Sent from my iPad using H.A.M.B.
     
  7. 1946caddy
    Joined: Dec 18, 2013
    Posts: 1,703

    1946caddy
    Member
    from washington

    How about a picture of your Model A. Hard to imagine a tire hitting a fender on a Model A with 16" wheels and tires and a non dropped axle. The fender should be setting about 4" above the tire.
    Stock Model A axle has 1" factory drop and a 1937 has a 2 1/8" factory drop.
    Here's a picture of a stock Model a with 16" wheels and tires, notice the height above the tire. A 37 axle would only reduce that height by 1 1/8" inch and still should be well above the tire. A stock 37 axle is 2" narrower than a Stock Model a axle and would reduce the chance of hitting the fender.
    00c0c_ld6H3q30zJH_600x450.jpg
     
  8. Deuce Man
    Joined: Jul 31, 2015
    Posts: 199

    Deuce Man

    Hey lou, that was quick! Hope you enjoy the 32. This might sound like a dumb question, but where do you measure the kingpin and spring perch centers on a ford beam axle? I get almost a half inch difference between the top of the holes and the bottom.
     
  9. 1946caddy
    Joined: Dec 18, 2013
    Posts: 1,703

    1946caddy
    Member
    from washington

  10. 41rodderz
    Joined: Sep 27, 2010
    Posts: 5,198

    41rodderz
    Member
    from Oregon

    Most measure at the top center of the holes.
     
  11. Haha...I clicked on your link to find the banner pic with my old 52 Chevy next to Sid’s 56 F100 and another buddies chopped 53 Chevy. Sorry for the derail...back to the regularly scheduled program. :p
     
  12. krylon32
    Joined: Jan 29, 2006
    Posts: 6,618

    krylon32
    Alliance Vendor
    from Nebraska

    I use a 47 inch So-Cal forged axle on my full fendered Model A customer chassis. I just checked the kingpin width on a dropped 33-36 axle and it's 48 inches. I've never had an A axle dropped.
     
  13. Deuce Man
    Joined: Jul 31, 2015
    Posts: 199

    Deuce Man

    46 caddy, remember there is quite a bit of difference between a 28-29 front fender and a 30-31. I will have to get someone to download a couple of pictures tomorrow. Rich
     
    Pass The Torch likes this.
  14. Deuce Man
    Joined: Jul 31, 2015
    Posts: 199

    Deuce Man

  15. alchemy
    Joined: Sep 27, 2002
    Posts: 15,862

    alchemy
    Member

    Your roadster sits nice and your truck sits like a truck. Copy the roadster specs into the truck.
     
    teach'm and Malcolm like this.
  16. 31Apickup
    Joined: Nov 8, 2005
    Posts: 2,311

    31Apickup
    ALLIANCE MEMBER

    I agree with alchemy. What are you running for front brakes, some of the disc brakes kits push the wheels out further.


    Sent from my iPhone using The H.A.M.B. mobile app
     
  17. To me it looks like you’re front axle is pretty far forward in the truck.
    Are you running the spring in front style suspension that goes with the 37 axle?
    A few pics would end the guessing games here
     
  18. 1946caddy
    Joined: Dec 18, 2013
    Posts: 1,703

    1946caddy
    Member
    from washington

    019.jpg 020.jpg
    The front tire on the coupe appears to be larger than the roadster's.
    Did you ever measure your axle to make sure it is a 37? You need a special spring that is longer to mount a spring on top of a 37 axle.
    This is a picture of my dropped and stretched to 48 1/2", 1937 axle with a Posie spring to mount over the axle. Model A axle's are 50 1/2" and when dropped, are 48 1/2". You can get after market axles that are narrower.
     
    Last edited: Jun 2, 2020
  19. Pass The Torch
    Joined: May 18, 2018
    Posts: 566

    Pass The Torch
    ALLIANCE MEMBER

    I swear, sometimes the HAMB is reading my mind: I'll be tackling the same thing here shortly.
     
  20. Deuce Man
    Joined: Jul 31, 2015
    Posts: 199

    Deuce Man

    Been away for a couple weeks walleye fishing. Back to my truck. Axle is in the correct position as the frame is basically a stock model A. Brakes are 40 ford hydraulics. I agree with Alchemy on duplicating the geometry of my roadster axle, where you measure is important and I think I got it now Thanks guys Rich
     
  21. 1oldtimer
    Joined: Aug 21, 2003
    Posts: 7,590

    1oldtimer
    ALLIANCE MEMBER

    I have a '36 axle in my '28, it was lowered but not stretched. it will be full fendered.
    steering-5.jpg
     
  22. Bob Unck
    Joined: Jul 7, 2020
    Posts: 8

    Bob Unck
    Member

    Can you tell me what your hub to hub dimension is with that axle and wheel offset? I am looking at aftermarket dropped axles and trying to figure out what width I need, I am planning to go with aftermarket disc brakes on the front just due to parts availability so I know that will likely play into it as well. Here's a picture of the car mocked up just to figure how much I need to lower.
     

    Attached Files:

  23. alchemy
    Joined: Sep 27, 2002
    Posts: 15,862

    alchemy
    Member

    Bob, since you already have the wheels/tires, you should probably work backwards. Next buy the brake kit and spindles, and assemble them to the wheels. Then measure in between to find the axle width that will work. It will probably be a 46" axle. I think SoCal or Roadster Supply Company are the only vendors with a forged new 46" axle right now.

    If you want an old axle dropped, I bet some of the guys (Andy Kohler) could narrow up a Ford as they do the drop. Might not be all the way to 46" but could get close. Call Andy.
     
  24. Bob Unck
    Joined: Jul 7, 2020
    Posts: 8

    Bob Unck
    Member

    Thanks for the input. just trying to cheat a bit.
     
  25. dirt t
    Joined: Mar 20, 2007
    Posts: 4,669

    dirt t
    ALLIANCE MEMBER
    from Kingman,AZ
    1. HAMB Old Farts' Club

    I bought a dropped axel with 46" kingpin centers. Most are 48".
    the 46" moves wheels 1" in on each side, This puts your wheels in the center of fender crown.
     
  26. jimgoetz
    Joined: Sep 6, 2013
    Posts: 401

    jimgoetz
    Member

    This is an old (1950?) dropped and stretched axle. They used to refer to this style as "taffy dropped".
     

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