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Technical 39 ford coupe rear springs

Discussion in 'Traditional Hot Rods' started by twostickmutt, Jul 25, 2020.

  1. twostickmutt
    Joined: Oct 18, 2015
    Posts: 123

    twostickmutt
    Member

    just curious as to what is a good parallel rear spring for my 39 deluxe coupe. it has parallel 4 leaf with the rear eye reversed now with new gas shocks and i hate the way it rides. sometimes it feels like it just bottoms out when hitting the right dip in the road. and there is hardly any arch to the springs now..i wouldn't mind if it rode a little stiff over hearing that bottoming out THUD at times. thanks for any advice.
     
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  2. birdman1
    Joined: Dec 6, 2012
    Posts: 1,467

    birdman1
    Member

    i put air shocks on mine. then I put another leaf and it did a better job at preventing the bottoming out.maybe there simply isn't enough travel left in the rear susupension before it hits the stops
     
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  3. twostickmutt
    Joined: Oct 18, 2015
    Posts: 123

    twostickmutt
    Member

    thanks birdman. did you add the other leaf right under the main leaf. i've been thinking about that being an option too.
     
  4. alchemy
    Joined: Sep 27, 2002
    Posts: 18,837

    alchemy
    Member

    If you want the same ride height, installing parallel leaves won't make it ride better. It will still bottom out at the same point. Either C notch the frame, or raise it up.

    If you think stiffening up the current springs might help, it's rather easy. Get a donor stock spring and see which leaves are missing from your current spring. Then put them in. It might make it sit a tad higher, but probably not much. You can arch the new leaves to match the current ones and it will help keep the ride height the same.
     
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  5. twostickmutt
    Joined: Oct 18, 2015
    Posts: 123

    twostickmutt
    Member

    alchemy it has parallel springs in it now. was like that when i bought the car. i wouldn't mind the back end to sit a little higher either. i think the spring kit was from C E though not sure. the previous owner put the kit in along with a nova rear end. he's since passed on so i cant question him to see just where he got everything. i'm going to change the rear to 3.08s and while the rear is out i'll bring the springs up to the local spring shop and see if they can beef them up just a freckle.
     
  6. alchemy
    Joined: Sep 27, 2002
    Posts: 18,837

    alchemy
    Member

    Sorry you said 4 leaf and I read "4 bar". Yes, I think having a local shop add a leaf might stiffen them up a bit and maybe add a little height.
     
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  7. How much travel is available as it sits now?
     
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  8. twostickmutt
    Joined: Oct 18, 2015
    Posts: 123

    twostickmutt
    Member

    i'm thinking that would be a good start. thanks.
     
  9. My ‘40 Chevy convert weighs in about 400 pounds more than a coupe or sedan. I bought new rear springs 20 years or so ago...had to add a couple leaves from the old broken springs and the re-arch the pack a bit. I tried gas shocks and didn’t like them. Used an old paper Monroe shock catalog to find a suitable regular shock. Lotsa miles an the rear is under control. All replacement items are not always the same.
     
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  10. twostickmutt
    Joined: Oct 18, 2015
    Posts: 123

    twostickmutt
    Member

    i was wondering too that if i got rid of the reverse eye in the rear of the spring and had a regular eye made up in a new main leaf to match the front eye ,if that wouldn't lift it up a bit and help out with the bottoming out. I've never messed with springs very much only to change the complete units.
     
  11. alchemy
    Joined: Sep 27, 2002
    Posts: 18,837

    alchemy
    Member

    If you are going to go having a new main leaf made, they might as well adjust the arch a little while making it. You can tell them what you want and they should be able to make it. Tell them you want it stiffer and one inch higher and they can make it.
     
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  12. treb11
    Joined: Jan 21, 2006
    Posts: 3,789

    treb11
    Member

    If you are taking it apart, just have the springs re-arched. If the ride is otherwise acceptable. No need to fiddle around with extra leaves adding unknown spring rates to the spring pack. That said, there is no guarantee the re-arched springs will hold that shape.

    Tip: the CE kit used 60-69 Dodge truck FRONT springs and 63 - 79 Corvette shock absorbers.
     
  13. We had a spring shop (Muskegon Brake) in my town for as long as I can remember. It closed about 10 years ago. It might have done work for the brake garage but I never saw anyone about the spring building. Within the last year or so there is activity but the gate is closed to the public so I don't know if they are in the spring business again or not.

    I priced leave springs for Eaton in Detroit and about had a heart attack.

    The CE springs are essentially Dodge pickup front springs....they are wider, shorter, almost flat, and stiff. Never been a fan but they are available and you can remove a leaf if necessary.
     
  14. oldolds
    Joined: Oct 18, 2010
    Posts: 3,357

    oldolds
    Member

    Where is it bottoming out?
    It could be that your shocks are a bit too long and bottoming out on them. Or is it hitting the stops? A long leaf under the main can make it stiffer and not change the ride height or raise it up. It depends on how much arch is in it. You could have the springs re-arched also. That would raise it and not make it much stiffer.
     
  15. twostickmutt
    Joined: Oct 18, 2015
    Posts: 123

    twostickmutt
    Member

    i want to thank everyone for all the advice on here......been a big help !
     
  16. chucka
    Joined: Oct 29, 2018
    Posts: 66

    chucka

    For what it's worth - - - had similar problems with Posies parallel leaves in my '32 several years ago. After removing and adding back leaves I finally called Posies - - blind luck, Ken himself answered the phone! After describing what I'd been going through, he asked me what I was using for shocks. When he found out they were gas,, he recommended putting all the leaves back and changing to oil filled shocks. Told me gas ones don't work well with leaf springs - - didn't know why but was very sure. He was right!! Does it make sense? Certainly not, but it worked for me.
     
  17. PA22Tim
    Joined: Feb 26, 2020
    Posts: 4

    PA22Tim

    I used IH Scout front springs on my 39 and they are a bit on the stiff side but they are short and narrow. They had too much arc to them so I flattened them some by pinning them down on top of a oak 4x4 with my car hoist and pounded on them with a sledge. Not a fun process. They were a stack of seven leafs and I am using five.
     
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  18. 31Apickup
    Joined: Nov 8, 2005
    Posts: 3,103

    31Apickup
    Member

    As treb11 mentions Chassis Engineering uses Dodge pu front springs. What do you have for bumps stops? Can you use shorter ones. And where is it bottoming out on the frame or is it the pinion or driveshaft.


    Sent from my iPhone using The H.A.M.B. mobile app
     
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  19. lostone
    Joined: Oct 13, 2013
    Posts: 2,261

    lostone
    Member
    from kansas

    Find a good old school shop and see if they can re-arch these. Leave the reverse eye spring, use it to your advantage. Add a little extra arch to the spring and help ride while not raising the car too much.

    If it were in my shop, thats how I'd re-arch them.
     
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  20. scrap metal 48
    Joined: Sep 6, 2009
    Posts: 6,077

    scrap metal 48
    Member

    Just have them re-arched a little.. A spring shop can do it easily for not much money and should be able to do it while you wait....
     
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  21. twostickmutt
    Joined: Oct 18, 2015
    Posts: 123

    twostickmutt
    Member

    just as an update....... got a little bit longer shackle bars and stretched the height 1 1/2 inches and tried the car out. well the thud is gone ,it rides better than it has since I've had the car and i'm happy with the way it sits now. you probably can call it a band aid but for now the band aid is staying put. again i want to thank everyone for all your help and suggestions.........STAY SAFE !
     
  22. birdman1
    Joined: Dec 6, 2012
    Posts: 1,467

    birdman1
    Member

    Yes , under the main leaf works best
     
  23. krylon32
    Joined: Jan 29, 2006
    Posts: 8,460

    krylon32
    Alliance Vendor
    from Nebraska

    We changed my 40 business coupe from a transverse rear spring to Chassis Engineering parallel leafs and added 2 inch lowering blocks and I do not have a bottoming out problem and I like the way the car rides. When I was still building 35-40 customer chassis I did most of them with a CE rear spring setup and had no complaints.
     
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