Pair of main leifs needed

F Body General Discussion

  1. BudW

    BudW Well-Known Member

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    Those 4-leaf springs look really good for being 40 years old (compared to a lot I’ve seen).

    1 cm between sides is not noticeable.

    Been my experience (others experience may/will vary) that most cars over 20-30 years old, the rear springs will sag about 2-3 inches (5-8 cm).
    I would be saying a figure closer to 6 cm figure (maybe 6.5?) would be needed.

    Note: be sure to adjust your front torsion bars after rears get back together.
    Then, car will need to be re-aligned because a few different alignment angles will have changed.

    While springs are off, be sure to replace the rear shackle bushings (fairly cheap).
    If the front bushings are broken or have heavy cracks in them, you might want to consider changing them as well. If not broken or heavily cracked – I would leave them alone.

    Something I do on my own cars – is I place a stud, steel rod or something similar into the front bushing holes – to firm up the bushings. The average person might not notice anything, but if you drive car hard (which I do), you can notice the difference.

    I don’t recommend polyurethane for front bushings or for shackle bushings.
    That said, I do recommend to either toss the Iso-Clamp system and use the older shock plates OR replace the rubber biscuits with polyurethane ones.
    Poly Pads.JPG
    http://www.energysuspensionparts.com/5.6106
    Note: this is one source of these pads – there are others out there as well.

    Note: I recommend using the older style shock plate – but many here have used the poly pads (above) without any issues.
    Either version will make car handle much better
    BudW
     
  2. Toro67

    Toro67 Well-Known Member

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    Hi Bud - Thanks for the input.
    I have the new shackle bushings ready, and the front bushings look fine.
    I will take the springs to the shop today and also get their opinion on how much they need to be bent back.
    Since I never drive the car hard I feel no need to alter or remove the iso-clamps at this time.
    The biggest handling issue I have with it is the sloppy steering response and the fact that the PS is 100% active at all speeds. This would be the first point for me to fix before looking at firming up the suspension.
     
  3. BudW

    BudW Well-Known Member

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    The P/S on our cars are a bit “over active”.

    This company does a great job on both rebuilding the steering gears as well as making the power assist more to your liking: http://www.firmfeel.com/fmj_body_mopar_power_steering_box_rebuild.html
    FFI Steer Gear.JPG


    The Iso-Clamps (rear springs) and the front K-frame mounts will make the car feel loose, sloppy and unresponsive.

    Try this. In an empty parking lot, go about 15-20 MPH and try to turn car hard Left then Right (or a series of hard turns back and forth.
    On my cars, you can literally feel the play in K-frame bushings give, before car actually starts to turn.

    The rear Iso-Clamps (or removal) has little to do with performance. After replacement, the car just feels so much better to drive, especially over bumps or braking.
    Chrysler added those to make car feel or ride better – but in my opinion, they made the overall ride feel worse.

    After removal of rear Iso-Clamps and replacing front K-frame bushings with something more solid (Poly, aluminum or cast iron) improves the ride of car - a huge amount.
    By also replacing the steering gear with a FFI unit – you would think you are driving a new car.

    If you have anyone in your area with an older stock A, B or C or E-body (B or C-body made before ’72) – see if you can take a ride in it (a leisure drive in town, in a parking lot, over some semi-rough roads, etc.). You will feel a difference. More so if driving it hard (like I do).

    My wife can even tell the difference in passenger seat, on a leisure drive.

    The front K-frame mounts are not that easy to change – but is great to do when engine is out or doing major suspension work.

    I mainly notice the rears when braking slightly harder than normal – to a hard brake, on slightly wavy or on rough roads. That rear-end hop can be un-nerving.
    BudW