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40 ford wheels on a model a

Discussion in 'The Hokey Ass Message Board' started by rustyrods, Nov 7, 2012.

  1. rustyrods
    Joined: Jun 14, 2005
    Posts: 339

    from Dixon,Il.

    Why don't these 40 Ford wheels set flat on my Model"a" drum? I'v had them on "As' before.
  2. Photo's?,,you might need spacer rings. HRP
  3. When wire wheels (1928-35 Ford and aftermarket Kelsey and Motor Rim and Wheel, I am not sure about AR wheels) are installed on drums designed for hydraulic brakes it is necessary to use a spacer to make the wheels have full contact (support) and avoid cracking when they are installed. The reason for this can be seen by looking at a Model A brake drum (photo 1). There is a raised area in the center that contacts the wheel when it is bolted onto the hub/drum. This same raised area was replaced with individual cast in/machined raised areas on the 1932-35 wheels (photo 2). The 1940-48 drums were flat in this area (photo 4). Photo 3 shows the aftermarket spacer necessary to provide the raised area setting on top of the brake drum waiting for the tire and rim to be installed (make sure your studs are long enough) These spacers are available from MT Car Products as part # 5000, Speedway as part # 91065470, and Sacramento Vintage Ford Parts as part # 05199-8 as well as many other sources. This addresses the problems most likely to be encountered by the Model A Ford owner but there a few other related problems that might be encountered. Check your mechanical brake drums as some people grind of the ring (or individual cast in raised areas on the later drums) to run solid rims. If you want to run wire wheels on these modified drums you would need a spacer. The opposite (but even more serious) problem is encountered when running 1940-48 solid rims on stock mechanical brake drums where a different spacer is required to make up for the fact that the solid rims expect to be mounted to a flat drum.

    Attached Files:

    Last edited: Jul 24, 2018
  4. el Scotto
    Joined: Mar 3, 2004
    Posts: 4,357

    el Scotto
    from Tracy, CA

    You need to grind down the humps on the drums.

  5. tommy
    Joined: Mar 3, 2001
    Posts: 14,757

    Member Emeritus


    from a 50's hotrod catalog
  6. fxstc127ci
    Joined: Jul 4, 2012
    Posts: 104


    Just went through all this! They will not work, there is not enough material on the model a hub to machine.They become to thin and it will not be safe! Run 35 wheels until you round up 40 brakes.
  7. donbatey
    Joined: Sep 14, 2010
    Posts: 46


    Just had a similar problem fitting some mercury steel wheels, re drilled the hubs for longer studs and made/ fitted a thin spacer as in the photos, works a treat!
  8. wheelkid
    Joined: May 25, 2006
    Posts: 1,204

    Alliance Vendor
    from Fresno, CA

    There was an old steel aftermarket wheel that is correctly shaped to go on the early mechanical brakes. I've got a few, give me a call at 559-322-2128 if you're interested
  9. steveoin818
    Joined: May 10, 2011
    Posts: 4


    im going thru the same deal...i wanna put my 40 solid wheels on...and of good..
  10. 31Apickup
    Joined: Nov 8, 2005
    Posts: 2,623


    Here's a picture of a wheel that was on a model A for a number of years without a spacer. You can see it is cracked at each lug hole and the lug seat is actually torn away.

    Attached Files:

  11. Tedders
    Joined: Oct 18, 2012
    Posts: 419


    Dealing with this right now, the hub center bore fit perfectly, bolts are to short



  12. Asphalt Outlaw Hero
    Joined: Dec 9, 2006
    Posts: 970

    Asphalt Outlaw Hero
    from Dixie

    I was talking to a friend who does a lot of builds. He said you need to put in longer bolts. You will have to open up hub holes. Here is what you need Use Dorman studs # 610=234. Use a 19/32 drill to open holes.
    Center of old drums were like sheetmetal. The spacer takes up some room. Pretty soon you have lost 5/16 of an inch.
  13. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    A--'34 type hub needs a spacer OUTSIDE the studs to support '40 type wheel or they will crack from lack of support. Due to location of the stresses, cracking is much more likely and more destructive than that caused by the opposite mess, wires on late hubs.
    This used to be a standard catalog item sold via all speed or Model A parts catalogs...I think this old hotrod may be commercially extinct, as current fashion is wires on later drums, requiring that extra support inside the studs...
  14. Andy
    Joined: Nov 17, 2002
    Posts: 4,718


    Another problem is that the 40 wheels have a rounded inner edge. The rounded portion does not line up with the raised tabs on the early drums. You would need a plate that covers the tabs so the inside of the wheel is supported. I recommend machining off the tabs as stated.
    triumphleroy likes this.
  15. HarveyWallbanger
    Joined: Jul 30, 2010
    Posts: 57


    My dad and I dealt with this last summer. I forget the dimensions, but we made spacer rings out of approximately 1/4" steel plate. They were cut with a plasma torch, then turned smooth on a lathe. Lug holes were drilled and tapped. Old studs were removed and longer bolts threaded in through the hubs. The bolt heads need to be machined a little on the inside to avoid clearance issues with the brake internals.
    As far as I can remember, the only difference between doing the fronts and rears was the inside diameter of the openings.
  16. Ed Rios
    Joined: Jan 18, 2016
    Posts: 11

    Ed Rios

    Great info. Thank you.
  17. I have an extra new set of these that have never been used. I will be bringing them to sell at Hershey.
    [​IMG] Location C4J-36

  18. Mt Kiyotee
    Joined: Mar 7, 2019
    Posts: 18

    Mt Kiyotee

    All the info us newbies need. Thanks fellas!!
  19. Cliff Ramsdell
    Joined: Dec 27, 2004
    Posts: 1,266

    Cliff Ramsdell

    Bump up useful info.

    Cliff Ramsdell

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