Help with rear leaf spring bushings

Suspension, Steering and Chassis

  1. Thanos

    Thanos Active Member

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    So I need new spring bushings. I have the rear shackle bushings, just going with Moog, but it seems there are a few choices for the front eye. Best I can tell I have a 1.5" bushing with a 1/2" bolt. Does that sound right for my 71 Demon? Kind of hard to get good measurement while its still in and I don't like taking things apart unless I have the new part. Can anyone make a recommendation (rubber, poly) maybe a brand and part number? I dunno if this makes a difference but it originally had a 6 in it.
     
  2. Mopar Tim

    Mopar Tim FABO Gold Member FABO Gold Member

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    Poly in the front eye is good, just lube it on assembly, other it will squeak...IMO
     
  3. Mopar Tim

    Mopar Tim FABO Gold Member FABO Gold Member

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    And /six springs have a smaller bolt there then the V8 versions, so if you car was a slanty car, the smaller bolt...
     
  4. Thanos

    Thanos Active Member

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    I should add that sometime in the past someone had upgraded the front and rear to a 73~76. I have no idea if they changed out the springs when they changed the rear end to an 8 1/4. Last owner was no help at all as he lost interest in this car years ago and really couldn't tell me much of its history at all.
     
  5. RedFish

    RedFish Well-Known Member

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    Standard hardware geometry doesn't always apply to automotive but I'm almost certain it does at this eye bolt. The hex is half again the diameter. 1/2" bolt = 3/4" hex wrench. 5/8" bolt = 15/16" hex wrench. So your wrench fit will define what the eye bolt is without removing.
     
  6. 72bluNblu

    72bluNblu FABO Gold Member FABO Gold Member

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    That's not really accurate information. Both of my '71 Dart's are 318 cars, and they both had 1/2" eye bolts. I don't know when, or if, the V8 cars started using the 5/8" diameter eye bolts, but I'm pretty sure you can't count on it for '71 seeing as how my cars were built in different plants at different times.

    Most of the aftermarket springs use a 5/8" eye bolt, there are a couple of exceptions.
     
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    • Marcohotrod

      Marcohotrod Well-Known Member

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      the bolt can be measured without removing it. and what lube is best for the new bushings?
       
    • TrailBeast

      TrailBeast Slightly Twisted Member

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      1/2 bolt uses the smaller bushing and the 5/8 bolt uses the larger bushing.
      The bolt tip can be measured on the inside of the bracket.

      I also heard /6 cars all had 1/2 bolts with the small bushing and v8 cars all had the 5/8 bolt with the large bushing, but I now know from experience that's BS.
       
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      • Hotwheels sr.

        Hotwheels sr. Well-Known Member

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        I ran into the same issue with my Demon.bought and returned a couple sets of bushings. Found the right ones at Rare Parts.
         
      • Thanos

        Thanos Active Member

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        Thanks Redfish, that's what I needed to know.

        Trailbeast, I heard the same and that's the reason for this search. A lot of sites don't tell you the sizes only that it fits and when I call or email they seem to have no idea what I'm talking about. I miss going to speed shops where the old mechanics worked and knew exactly what you needed. Now its just hourly/ commissioned people that depend on the computer to tell them...

        So I have The smaller bushing with a 1/2" bolt. Can someone give me a good brand/ part#?
         
      • TrailBeast

        TrailBeast Slightly Twisted Member

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        I used poly on my car from PST, but on one of the other cars I used a Moog rubber with the steel shell.
        Boy that was fun getting those in.:D
        The poly's are easy since they don't use a steel shell.
         
      • CodyS

        CodyS Well-Known Member

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        I have found that all the 340 cars my dad and I have owned have had 2 inch front bushings and the slant 6 cars had 1.5 inch bushings. I bought my last set of poly bushings from rock auto.
         
      • oldkimmer

        oldkimmer FABO Gold Member FABO Gold Member

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        All my A bodies from 67-76 have had the 1/2 bolt weather they were slant or v8 cars. If SS springs were installed u needed the 5/8s bolts and had to ream out the front hanger bolt holes. Kim
         
      • zkx14

        zkx14 Duster De-ruster FABO Gold Member

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        If still needed, I have a set of Energy Suspension for 1.5" eye I'll give you a good deal on if interested...
        My slant 6, 7-1/4 rear, 75 Duster had a 9/16" bolt and 2" eye. :BangHead:
        So I needed the larger bushings and had to open up holes on hangers for new 5/8 bolts. Had already bought the 1.5's that were 'supposed' to be in all the slant, 75's long time before, so were no longer returnable. Just sitting here gathering dust...
         
      • ChuckDock

        ChuckDock Well-Known Member

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        Thats good to know about the polys. I just spent 16 hours replacing my uca bushings...wonder if poly would have been the way to go there as well.
         
      • TrailBeast

        TrailBeast Slightly Twisted Member

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        The problem with using poly in the uca's is that I don't think they make an offset poly bushing for correcting our caster.
         
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        • ChuckDock

          ChuckDock Well-Known Member

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          Ah...and that is why I did replace mine, to be able and use the offset ones. Ok, so I didn't miss out on time savings last weekend.
          Thanks!
           
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