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Technical Help ID my sub frame

Discussion in 'Traditional Customs' started by skin_dog1, Jul 16, 2018.

  1. skin_dog1
    Joined: Jun 26, 2014
    Posts: 21

    skin_dog1

    I just bought a 40 Chevy that has an ifs subframe bolted under it. It’s not one I recognize and not sure these pics will be much help. Any one got any idea what this might be? A534FD7B-0335-4400-88E5-18B6AB334A96.jpeg B6F97B37-B9FA-44B1-A75C-D4DC5EFDD44D.jpeg
     
  2. mgtstumpy
    Joined: Jul 20, 2006
    Posts: 7,695

    mgtstumpy
    Member

    upload_2018-7-16_17-13-24.png
    GM IFS #5328534 Looks to be OEM with upper and lower rebound rubbers matching original schematics? GM casting on upper control arm
    upload_2018-7-16_17-18-51.png
    upload_2018-7-16_17-19-17.png
     
  3. Torana68
    Joined: Jan 28, 2008
    Posts: 1,112

    Torana68
    ALLIANCE MEMBER
    from Australia

    Looks like your standard knee action to me.
     
  4. 56premiere
    Joined: Mar 8, 2011
    Posts: 1,445

    56premiere
    Member
    from oregon

    I think they are right. Is that a crack on the upper arm?
     
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  5. BJR
    Joined: Mar 11, 2005
    Posts: 5,931

    BJR
    Member

    Better change that upper shock mount, angle is way off.
     
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  6. squirrel
    Joined: Sep 23, 2004
    Posts: 43,956

    squirrel
    Member

    stock original suspension! with (badly) added tube shocks. how about that.
     
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  7. Hnstray
    Joined: Aug 23, 2009
    Posts: 10,885

    Hnstray
    ALLIANCE MEMBER
    from Quincy, IL

    Cobweb...

    RAY
     
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  8. ...................I hope you are right, but the more I look at the pictures, the more it looks like a crack!:eek:
     
    lothianwilly71 likes this.
  9. Looks stock to me,with the exception of the shocks. HRP
     
  10. skin_dog1
    Joined: Jun 26, 2014
    Posts: 21

    skin_dog1

    Well don’t I feel like an idiot. I wondered if it was original. But to be honest, it’s my first 40’s vehicle and had no clue it would’ve had ifs. Assumed it was a straight axle. Looks like I’ll be doing a MII swap. The steering blows. It’s got a late model steering column and not sure if the geometry of that install is all wrong or it’s just worn out 80 year old parts.
     
  11. jeepsterhemi
    Joined: Dec 5, 2009
    Posts: 2,099

    jeepsterhemi
    Member

    You are not that wrong....1940 Chevrolet Special and Master De Luxe got an "Independently Sprung Front Axle" .......and Master "85" got "Conventional Front Axle".....
     
    skin_dog1 likes this.
  12. What is this Mustang II you speak of ?
     
  13. Hnstray
    Joined: Aug 23, 2009
    Posts: 10,885

    Hnstray
    ALLIANCE MEMBER
    from Quincy, IL

    Skin_dog1..........'Mum' is the word.....;)

    A surgical 'edit' of your post would be even better....

    Ray
     
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  14. ...that's orig. 40 Chev independent front susp,..not called knee action , knee action fronts were only available from 34 thru 38...
     
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  15. anthony myrick
    Joined: Sep 4, 2009
    Posts: 4,845

    anthony myrick
    Member

    Wow. Original and not a hacked graft. You did good.
     
  16. town sedan
    Joined: Aug 18, 2011
    Posts: 1,106

    town sedan
    ALLIANCE MEMBER

    Think again and read the OP's 2nd comment on this thread. He's happily going to replace it with street rod parts.
    -Dave
     
  17. VANDENPLAS
    Joined: Dec 14, 2009
    Posts: 1,990

    VANDENPLAS
    Member

    They used knee action front ends up to 54
    Up to 63 in the corvettes

    Different set up then yours but kneee action the sane
     
  18. anthony myrick
    Joined: Sep 4, 2009
    Posts: 4,845

    anthony myrick
    Member

    Yes
    If he does update it he can do it a lot easier than messing with a hack job
     
  19. mgtstumpy
    Joined: Jul 20, 2006
    Posts: 7,695

    mgtstumpy
    Member

    Sounds like all they did was cut OEM column shaft and graft a new column in if using original steering box which might be OK and only require adjustment? The only thing required when that column was swapped in was a universal joint connecting it to box output shaft and a seal on tube where it was cut. The column needs to be secured properly at toeboard and lower dash rail. Post some photos of column attaching points and universal joint. It could be poor workmanship or fabrication (DD shaft) that needs rectification apart from tube shock angle. You already have disc brakes. Don't overthink it, the OEM suspension including kingpins might be OK and still safe to use.
     
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  20. Knee action was dropped after 1938...period....after that it was called independent front susp.
     
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  21. Torana68
    Joined: Jan 28, 2008
    Posts: 1,112

    Torana68
    ALLIANCE MEMBER
    from Australia

    So the indipendant front suspension from 1938 is nothing at all like the indipendant front suspension in 1939 or did the name change and not much else Edit ;the earlier one looks like shit!
     
  22. 24riverview
    Joined: Jan 13, 2008
    Posts: 807

    24riverview
    Member

    My opinion also rusty1 but Chevy's brochure writers must not of gotten that memo, LOL. img3245_71022-1.jpg
     
  23. Hnstray
    Joined: Aug 23, 2009
    Posts: 10,885

    Hnstray
    ALLIANCE MEMBER
    from Quincy, IL

    The suspension Chevrolet first used that was commonly referred to as 'Knee Action' also was known by it's designer's name ...DuBonnet. It was was a massive and ugly appendage and bears almost no resemblance to the photo above in post #22.

    Given that the DuBonnet was commonly called 'Knee Action', the marketing people most likely decided to capitalize on the name recognition and, as the ad copy above indicates, referred to as 'the improved knee action'......which it certainly was. However, it is arguable that any upper and lower A arm style suspension could be referred to as knee action. The design's main change was the substitution of ball joints for the pin and bushing pivots in the earlier designs.

    Ray
     
    Last edited: Jul 16, 2018
  24. anthony myrick
    Joined: Sep 4, 2009
    Posts: 4,845

    anthony myrick
    Member

    any you guys lower one with stuff like this
    butch.jpg
     
  25. Tons of bolt-on kits that will fit this frame, all the same stuff that works for 49-54 cars will work here.
     
  26. anthony myrick
    Joined: Sep 4, 2009
    Posts: 4,845

    anthony myrick
    Member

    I just looked up some dropped uprights. Man they are proud of those.
     
  27. ...I stand corrected,..looks like even the GM ad writers continued to refer to the front susp. as "knee action",...altho it really was coil spring,..here's what the true knee action fronts looked like,...
    [​IMG]
     

    Attached Files:

    Last edited: Jul 17, 2018
    Hnstray likes this.
  28. skin_dog1
    Joined: Jun 26, 2014
    Posts: 21

    skin_dog1

    3DD28740-878C-4B61-8DDE-BECE523DCC13.jpeg No u joint. That may be why the steering is so jerky. Imagine a slightly bent shaft rotating, getting right at one point then freeing up at another. Somehow I doubt that shaft is perfectly straight from the steering whee to the steering box.
     
  29. If the same guy who installed the tube shock modified the steering, I'd be worried.

    Looks like part of a u-joint (welded!) at the fire wall. What is that?
     
  30. skin_dog1
    Joined: Jun 26, 2014
    Posts: 21

    skin_dog1

    There’s a lot of crap that’s got to be corrected with this car.
     

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