Register now to get rid of these ads!

Technical Assembly sequence for four bar front end 1931 Ford

Discussion in 'The Hokey Ass Message Board' started by Aussie A, Feb 25, 2017.

  1. Grateful advice as to whether there is a particular sequence when re-assembling an early Ford, four bar front suspension.

    I recently removed a 4" drop tube axle and super low Spring to replace them with an IBeam and standard reverse eye Spring and l am having difficulty getting them to easily bolt back together.

    Can anyone tell me if there is a particular sequence that works best when conducting final assembly?

    Example, do you bolt the Spring to chassis, axle to Spring then attach four bars? Or does another sequence work best?

    Thanks
     
  2. alchemy
    Joined: Sep 27, 2002
    Posts: 20,406

    alchemy
    Member

    I'd put the bat wings on the axle, the perches into the bat wings, then the spring and shackles onto the perches. If the spring won't fit because the arch is too tight, I'd remove the leaves (use two large C clamps and loosen slowly). Then after the shackles are tight I'd reinstall the other leaves in the opposite fashion.

    Put this assembly up into the crossmember and loosely install the spring clamp. Then hang the bars one by one, and adjust preliminarily to approx length. Once everything is assembled and on wheels, you will need to readjust the caster with the bars.
     
  3. Thanks for getting back to me. I am currently thinking my 4 bars have been set to short. Very difficult to get any of the bolts in without force, and then only one each side.

    I had commenced with the sequence you suggested, and have now tried a number more to no avail. The car has been together for 20 years, with no weird tyre wear patterns so I had assumed that I might have needed to keep the setup as is. Only problem is that I can't get it to bolt up.

    Will take another look tomorrow.

    Regards
     
  4. pasadenahotrod
    Joined: Feb 13, 2007
    Posts: 11,775

    pasadenahotrod
    Member
    from Texas

    Early Ford cars were designed with the suspension springs mounted under tension so the spring would be the last thing assembled to the axle using a spring spreader.
    One reason was to eliminate the need for a Panhard rod.
    Starting in 1942 the need for a softer ride to compete with GM and Chrysler and others necessitated the use of Panhard rods front and rear since the springs were now longer and had large rubber bushings in larger spring eyes.
     

  5. I used a ratchet strap to pull the axle back. Put the bolts in and checked the king pin angle. Release the strap turn the adjusters whichever way they needed. Then the ratchet strap again.
     
  6. alchemy
    Joined: Sep 27, 2002
    Posts: 20,406

    alchemy
    Member

    Are the bars looking like they are twisted? Maybe your batwings are on the wrong side.
     
  7. Thanks Guys, I was starting to think along the lines of an adjustable chain / ratchet strap to pull it in.

    Here is some more details from todays efforts.
    I decided to remove all the four bars and measure them from front bush centre to an estimated rear bush centre (the rear bushes are angled.

    Here are the rough measurements;
    LH Upper 20.67" 525mm
    RH Upper 20.67" 525mm
    LH Lower 21 .65" 550mm
    LH Lower 21.26" 540mm

    Given the large difference between the top and the bottom four bar lengths, it is possible that the front cross member has not been aligned properly.
    Here are photos showing the four bars in relation to the batwings with the spring and axle hanging, noting lifting the axle should move the four bars further toward the batwing.

    Right Hand side showing easy bolt up, noting lower four bar is 10mm (.394") shorter than Left Hand Side lower four bar.
    RH Hanging.JPG
    Next two are Left Hand side showing easy bolt up, noting about 25mm needed to bolt upper, and 20mm to bolt lower.

    RH Hanging.JPG LH Hanging 2.JPG

    I also discovered the Right Hand lower end was bent, and the fixed bush was damaged.
    Bent End1.JPG Bent End2.JPG Bush.JPG

    I am considering making both lower rods equal 550mm (add 10 mm to the lower Right Side) and trying again. This should give me 5mm of thread inside the lower four bar. This should hopefully get me 10mm closer on the Left Side).

    I have been told the aftermarket axles (which this is), are symmetrical (can be installed with either side facing forward), so I assume the batwings are correct as they angle slightly to accommodate the batwings.

    I will keep you posted.

    Any further ideas gratefully received.
    Regards
     

    Attached Files:

  8. You need weight on the axle to compress the spring, ie. ride height. And I would attach the front ones first.
     
  9. 31Apickup
    Joined: Nov 8, 2005
    Posts: 3,366

    31Apickup
    Member

    The bat wings look like a new set, are they dimensionally the same as what was originally on it, I doubt that every manufacturer makes them exactly the same.
     
  10. alchemy
    Joined: Sep 27, 2002
    Posts: 20,406

    alchemy
    Member

    I agree that the batwings may be a different dimension than your previous version. And that bent end has to go!

    Most guys install the adjustable end of the four-bar on the back end. Is that changing your angle any? But it shouldn't have any difference in the length. So, maybe the original builder welded the frame bracket on a bit farther back on one side?
     
  11. Thanks guys, I will take some more measurements next weekend and keep you informed. Like all new cars it takes some time to discover all the "features " previous owners and builders have added. This is the first early Ford front end I have owned so I really appreciate the advice.
    Regards
     
  12. redo32
    Joined: Jul 16, 2008
    Posts: 2,137

    redo32
    Member

    Hey Aussie, We don't know who built your chassis or the brand of the 4 bar, so you have a custom installation that you changed components. The length of the 4 bars is unimportant except as a reference point for each side assuming the brackets are consistent. What is important is that the axle is square with the chassis and has 7 degrees caster. The 4 bar just holds the axle in this position. Put weight on the axle and double check the squareness and adjust the 4 bars individually to fit. If the chassis is square the bars should close side to side. Here's a download from Pete & Jake. https://www.peteandjakes.com/wp-content/uploads/2016/10/2003A.pdf
     

    Attached Files:

  13. redo32
    Joined: Jul 16, 2008
    Posts: 2,137

    redo32
    Member

    Note that Pete&Jake's uses angled adjusters. Other makes weld the bushing sleeve in at an angle and use a straight adjuster in the front. Your bent adjusters are a concern.
     
  14. Thanks redo. Mine has the bend at the rear and the adjusters at the front.

    I will now measure everything for square, starting with reared and move forward from there.

    As previously suggested do you use a technique to pull / leaver the axle square and to correct angle? (Ratchet straps etc)
     
  15. DOCTOR SATAN
    Joined: Mar 21, 2014
    Posts: 710

    DOCTOR SATAN
    Member
    from okc

    I'd use the bar ends to adjust the axle....
     
  16. Thanks, my bars can't be adjusted while connected so if they need to be under tension some other method of holding the axle position during adjustment will be needed.
     
  17. redo32
    Joined: Jul 16, 2008
    Posts: 2,137

    redo32
    Member

    If you have to push or pull the axle to hook up the four bar you will put the shackles in a bind. The only reason to push or pull the axle is to get the proper caster. If that is the case then you need adjustable perches.
     

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.