Register now to get rid of these ads!

Technical F1 Pitman Arm

Discussion in 'Traditional Hot Rods' started by Richard Reed, Dec 13, 2018.

  1. Richard Reed
    Joined: Jun 17, 2016
    Posts: 175

    Richard Reed
    Member
    from Maine

    Does anyone know where I can find a 4.5" pitman arm to fit a F1 steering box? I have a 6" but hits the split wish bone. I could cut and weld that arm to the correct length but do not want to do that because of safety.
     
  2. F&J
    Joined: Apr 5, 2007
    Posts: 13,222

    F&J
    Member

    Before we go further without pics or whatnot...

    Have you put the car on stands and run full-lock to full-lock, and grabbed a measurement to a 4.5" mark on your current longer arm to the center of the steering arm ball? (I've seen so many screwed up builds on here over the years). You need full travel of the drag link to "full lock" on both stock Ford spindle stops. It only takes minutes to check that.

    Countless builds have the stops removed and mag wheel lug nuts installed to limit the travel...because..duh.....the split bones hit the tires on a full lock. Then they can't park in a tight spot, etc. Move the bones IN at the rear. That often makes lots of room for the pitman.

    Messing that much from 6 to 4.5 will change the steering ratio in a big way...even if you did or didn't lose full turning circle. Then the caster setting needs to be tuned to the faster ratio, the steering wheel diameter, front tire type, and scrub error if that's not right due to disc brakes, and or wrong wheel offsets.

    Hope I did not bore you. BTW welded arms are not unsafe if done properly....>>but most typical traditional styled cars can be built properly with these old Ford parts 'without' doing that.
     
  3. Mr48chev
    Joined: Dec 28, 2007
    Posts: 33,861

    Mr48chev
    ALLIANCE MEMBER

    Back when welded steering pieces weren't verboten we swapped ends on the VW Bus pitman arm on my T bucket. I hand sawed a V notch into the arm and then ground bevels on it and cut and put a point on the pitman arm end with an eye for a tie rod end so that it fit up in that notch tightly and a pro welder friend did the welding and we ground it smooth and I had it chromed. That thing is probably floating around Central Texas somewhere. It might shake someone up if they ground the chrome off an found brass though as we laid some brass over the weld to smooth it off slick .
    Still I have to go with what F&J said 100%, shortening the pitman arm that much is going to play hell with the turning radius.
     
    alanp561 and bct like this.
  4. Richard Reed
    Joined: Jun 17, 2016
    Posts: 175

    Richard Reed
    Member
    from Maine

    Give me a few minutes and I will send some pictures and give more detail as to what I done with the radius rods and steering.
     

  5. krylon32
    Joined: Jan 29, 2006
    Posts: 9,396

    krylon32
    ALLIANCE MEMBER
    from Nebraska
    1. Central Nebraska H.A.M.B.

    I'm not an expert on Ford Pitman arms but when I encountered a clearance, problem with my deuce pickups split bones and Hudson steering I went to a 34 Pitman which put the tie rod end on the inside of the Pitman instead of the outside. Problem solved.
     
    alanp561 and F&J like this.
  6. Richard Reed
    Joined: Jun 17, 2016
    Posts: 175

    Richard Reed
    Member
    from Maine

    I can turn the tires to both stops with an inch of clearance from the radius rods(no tire rubbing). The box is centered as you view JPG 1102 from the side. The pitman arm is splined in in such a way that it will not hang straight down. I would gain about 1.5" by moving the radius rod to the inside of the frame and would need to box the back side to mount the plate for the tie rod. The other thing is the position of the pitman arm as you see it now with the box centered. My brain as I see it, tells me it should be hanging straight down? Hope this gives you more info to work with. Thank you.
     

    Attached Files:

  7. GordonC
    Joined: Mar 6, 2006
    Posts: 3,140

    GordonC
    ALLIANCE MEMBER

    When I set mine up I centered the box and the front wheels and then checked where the pitman arm hung down. It was at a little bit of an angle so I took a file and filed additional groves in the inside so that I could rotate it forward or backward a tooth at a time on the steering box as I needed. From what I understand it is supposed to be level with the frame but many, including mine, run up hill a little bit to the steering arm. As for the bone I put my mounts on the inside of the frame rail and mount the bone from the backside. Seems to be ok. If you shorten the pitman arm up you will increase the amount of effort it will take to steer so be aware of that.
     
    alanp561 likes this.
  8. F&J
    Joined: Apr 5, 2007
    Posts: 13,222

    F&J
    Member

    Wives tale about dead straight down, for one reason only. The "side steer"drag link needs to travel more in one direction to full lock, compared to the opposite full lock. Ackerman is why.

    Normal hotrod practices, you grind out the "flats" to allow the pitman arm to be moved to any point on the spline. You must fix that angle that you show, as you will never get to full lock on a left turn as is.

    I will take your word on that...it could be just the angle of the pics. You do have the stock stops? You never want to give up any turn radius in a mock up, is why I ask.


    I would. I always get the bones under the car as much as practical. I have no way to prove it, but in my mind, when you get back to acting more like a wishbone (angles), everything plays better...... and I am fairly certain it helps on cars that have death wobble.

    BTW, nice build from what I see.;) It's good that you ask before getting all "welded up and chromed" as one we just saw on here recently.
     
    alanp561 likes this.
  9. Richard Reed
    Joined: Jun 17, 2016
    Posts: 175

    Richard Reed
    Member
    from Maine

    Thank you. I hope that I am getting wiser in my old age and not being the carpenter who measures once and cuts twice!!! The stops have not been altered in any way. I will unbolt the radius arms tomorrow and clamp them to the back side and see what happens. If it works and looks good I will fire up the welder.
     
  10. alchemy
    Joined: Sep 27, 2002
    Posts: 20,404

    alchemy
    Member

    Can you bend the arm a bit inward, taper the pitman halfway so the drag link comes from the inside (ala 32 Ford), and then have no collision between the pitman and wishbone? The taper is 7 degrees, and there's got to be a hot rodder somewhere near you with a reamer to borrow.
     
  11. sdroadster
    Joined: Jul 27, 2006
    Posts: 420

    sdroadster
    Member

    Move the bones to the inside of the frame rail. Take a 3 cornered file, and file an additional groove in the wide splined sections of the pitman arm. You'll then be able to install the arm in an position necessary.
     
  12. Marty Strode
    Joined: Apr 28, 2011
    Posts: 8,796

    Marty Strode
    Member

    Gordon, I think you have it backwards, if you shorten the pitman arm it will steer easier, and slower. If you lengthen the arm it will steer quicker and harder. Example below, I ran the bottom hole on the street, and the top hole when racing on dirt ovals. P1010004.JPG
     
    IronTrap and alanp561 like this.
  13. GordonC
    Joined: Mar 6, 2006
    Posts: 3,140

    GordonC
    ALLIANCE MEMBER

    I knew it was one way or the other Marty just having a senior moment! :D
     
  14. 42-48 passenger pitman angles in to ward the engine.Ive been told the Vega pitman fits the F1.Speedway has a 2 inch drop Vega pitman that would put it farther outward.
     
  15. Richard Reed
    Joined: Jun 17, 2016
    Posts: 175

    Richard Reed
    Member
    from Maine

    I happen to have a Speedway offset arm and along with moving the radius arms to the inside I should be golden.
     
    F&J likes this.

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.