1951 frame dimensions to repair bent frame

Discussion in '1947-1954' started by FarmerSid, Nov 5, 2014.

  1. FarmerSid

    FarmerSid Member

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    Hey all. Need some help from you all. Started working on my frame and it appears to be bent. A bit if a pisser. I've been jacking on it and have it much better but a little ways to go. I have all the manuals on CD but when I print the frame dimension pages, I can only make out a few dimensions. They are all blurry. Hopefully someone here can help me out.

    Some of the dimensions I need are:

    Width of frame at the three running board brackets.

    Width of frame at front cross member.

    Width of frame at rear cross member.

    Width of frame behind the C notch where the frame starts to bend in and go back to the rear of frame.

    Another question. Is the portion of the frame to the rear of the C notch after the inward bend the same height and parallel as the frame rails between the axles?

    Thanks! I'm having a really hard time figuring this out.
     
  2. Bill Hanlon

    Bill Hanlon Member

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    Any particular make and model of truck?
     
  3. FarmerSid

    FarmerSid Member

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    Sorry! 1951 Chevy 1/2 ton.
     
  4. morabuffalo

    morabuffalo Member

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    Don't have the dimensions, but height might be really be hard to figure...depending on all sorts of factors...I think I read a thread here where in many cases the right and left are off by a little bit because of the space science they used back then...lots of wear and tear...weak this and weak that...a little fatigue here and there...many time those shakles actually are sitting about a half inch up on one side, because of wear and you can't see it....but the big one is also in what stage is the frame....weight has lots to do with it....it falls when the body goes on...boards, steel, ply, or plastic....some trucks may even see the bondo effect....what is that? Weight!!! How much bondo is there? One sixteenth or two inches?

    Some things to ponder, but good luck, someone here will have those dimensions!

    rod
     
  5. FarmerSid

    FarmerSid Member

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    Thanks Ron. Something to think about for sure. I just want to get my frame straight and square and measuring to GM specs before I continue on. This is holding up progress!

    and like you said, I really hope someone can lend a hand.
     
  6. 52wasp

    52wasp Member

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    location

    FarmerSid,
    Please add your location in your signature. If, for example, you were near New Hampshire, I have a bare frame you could refer to with a tape measure(or purchase for short money).
     
  7. Chiro

    Chiro Member

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    Frame

    Like Mike says, frames for these trucks can be easily had for very little money. My frame was all chopped up and a big area of rot. I bought a parts truck with no bed or engine and a rotted out cab (but good frame) for $300.00 when I did my build. Might be worth the time, effort and dollars to take a look around.

    Andy
     
  8. FarmerSid

    FarmerSid Member

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    I'm in Ontario, Canada and added that to my profile. We are quite away's apart. Would it be too much to ask for you to grab a tape measure and measure it in a bunch of places? It would be a great help.

    Thanks!
     
  9. FarmerSid

    FarmerSid Member

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    Thanks Chiro! Another frame would be hard to find in my area. Seen a few but big dollars. $600 and way up from there. They don't pop up very often.
     
  10. Kens 50 PU

    Kens 50 PU Member

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    Interesting thread!

    I've found out a very interesting fact in the last 2 days! It's almost impossible to get measurements of a frame when it has all of its component parts attached to it!:D Sid, I know it's frustrating to be waiting on info when it's holding you back from going on to the next phase of a project and with that said, let me tell you what I know as fact so far. The width of the frame on my '50 measures 25 and 1/2 inches at the very front on the frame. The width of the frame at the very back of the frame is 46 and a hair. I've enlisted the aid of my best helper who promises me that she can help measure the width of the frame at each runningboard bracket in the morning, so check back tomorrow for those. In answer to your last question, if I read it right, is "yes". Pre-54 frames required wooden blocks between the frame and the bed to ensure that the bed would clear the rear axle notch. The size of the blocks before and after the notch was 2 and 1/4 inches +/- and given the fact that the dimensions were the same leads one to believe that the frame would be the same height on either side to ensure correct positioning of the bed.

    Hope this helps!

    Ken

    P.S. You may have already seen this, but if not, this is a great way to check if a frame is bent. http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0201.htm
     
    Last edited: Nov 7, 2014
  11. FarmerSid

    FarmerSid Member

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    Thanks Ken. Funny guy Ken! :D Those measurements when you get them, would be appreciated. That link I have seen and compared those measurements to mine. My front is 1/2" narrower but the back is correct. The front being narrower is funny as the stock cross member is still riveted in. Undecided if I should take it out and weld in back in at 25 1/2".
     
  12. Kens 50 PU

    Kens 50 PU Member

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    OK, measurements taken. Each measurement is taken at the front of each runningboard bracket. Front bracket measures 32 and 3/4 inches. Middle measures 36 and 1/2 inches. Back measures 41 and 1/4 inches.

    Now for the caveats. These are all approximate measures, as tailpipes, torque tubes, emergency brake lines, etc. may have altered an otherwise very straight shot from rail to rail! But as we used to say in school "+/- due to slide rule accuracy!" Yeah, I'm that old, yes I still have my slide rule and yes I still know how to use it. :D

    Hope this helps!

    Ken
     
  13. Bill Hanlon

    Bill Hanlon Member

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    You should have called Ken. Would have let Sarah off the hook. I'd bring my K+E Deci-Lon.
     
  14. FarmerSid

    FarmerSid Member

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    Thanks Ken. I will compare your measurements to mine tonight. Appreciate the help. I will update with what I found. Cheers!
     
  15. FarmerSid

    FarmerSid Member

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    Well........I measured my frame up. It's off compared to yours Ken. Here's the numbers:

    Front of frame: Mine=25 1/8" Ken=25 1/2" (correct)

    Front RB bracket: Mine=31 5/8" Ken=32 3/4"

    Middle RB bracket: Mine=36 1/4" Ken=36 1/2"

    Rear RB bracket: Mine=40 3/8" Ken=41 1/4"

    Rear of frame: Mine=46 1/8" Ken=46 1/32" (correct)

    I'm starting to wonder how good these frames where from the factory. My front cross member is still in the same position as it was when it left the factory yet it's almost 1/2" out.

    Maybe should remove the front cross member and put it back in to GM specs. Don't know what to do as the cab was repaired while it was still bolted to the frame.
     
  16. HotRod53

    HotRod53 Member

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    Sid I will measure mine in the morning and let you know what mine are
     
  17. cmkruse

    cmkruse Member

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    48-51 Shop Manual

    1948 - 1951 Chevrolet Truck Shop Manual page or section 2-2 has a frame straigtening table which list several key dimensions and is readable at least on my computer. I note that with most engineering drawings there is a tolerance allowance for any dimensional measurements but the table here doesn't list one. Absolutes are difficult to obtain in any environment. I would think that +/- 1/4 inch wouldn't be of much concern on these old truck frames but being from the old school I'd like to get it as close as I could to the factory specs myself. good luck with it.:)


    UPDATE: I should have read the previous page (2-1) on frame alignment. It states to use an "X" method and the measurements should be within 3/16.

    http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0201.htm
     
    Last edited: Nov 9, 2014
  18. HotRod53

    HotRod53 Member

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    Sid, I checked my frame and to be totally honest with you there isn't but about an 1/8 of an inch between yours and mine. my frame is bare right now i also checked the 48 I picked up a couple of months ago and and was about the same. hope this helps you out
     
  19. FarmerSid

    FarmerSid Member

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    Thanks HotRod. I appreciate it. Could bug you for a few more measurements?
     
  20. HotRod53

    HotRod53 Member

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    Sid what else do you need glad to be able to help
     

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