Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Will my fix keep the frame from cracking at the steering box? (pic)

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by KevinsK5, Jul 7, 2006.

  1. KevinsK5

    KevinsK5 1/2 ton status Premium Member

    Joined:
    Jan 17, 2005
    Posts:
    257
    Likes Received:
    13
    Location:
    Golden, CO
    I welded a piece of 3/8" diamond plate in between the front frame horns on my 77 to make it very strong. It's welded on all 3 sides, however I was not able to weld the last three or four inches on the drivers side nearest the crossmember. (because it curves in right there and I wouldn't be able to get the plate in if I cut it to fit that contour)

    Will this by itself hold the frame solid enough to keep it from cracking, or is a brace necessary? Thanks, Kevin

    P1010024.JPG
     
  2. walla2k5

    walla2k5 1/2 ton status

    Joined:
    Sep 5, 2004
    Posts:
    2,054
    Likes Received:
    1
    Location:
    Walla Walla, WA
    Dunno,since it isn't directly behind the steering box,only time will tell.
     
  3. mouse

    mouse 1/2 ton status

    Joined:
    Nov 10, 2003
    Posts:
    1,448
    Likes Received:
    0
    Location:
    Great Falls Mt
    It definitely adds rigidity to the front of the frame and will do so around the steering box as well. It should help. While you have it in that condition, drop the box and inspect the frame closely for cracks. Now is a good time to weld them up if you need to.
     
  4. jolane

    jolane 1/2 ton status

    Joined:
    May 27, 2004
    Posts:
    132
    Likes Received:
    0
    2X on this. NOW is the time to weld up a regular brace in there. I just did mine in a full bodied "stock" burb, and it was a pain having the work under the fender, around the inner fender, etc...
     
  5. roadnotca

    roadnotca 3/4 ton status

    Joined:
    Sep 16, 2005
    Posts:
    5,433
    Likes Received:
    1
    Location:
    Redondo Beach, CA
    X3. Now is the time to weld-in the shaped plate from the brace kit, the double thickness at the bolt holes alone, will go a long ways to keep the frame from tearing.
    Otherwise, thats one hello of a frame brace. Might as well weld the crossmembers up there too. If you check, you might find the rivets are probably loose.:D
     
  6. tin man

    tin man 1/2 ton status

    Joined:
    Nov 11, 2000
    Posts:
    149
    Likes Received:
    0
    Location:
    Roselodge Oregon
    You might want to take the time and weld in a kit. It will only cost about 65 bucks. It will be so much easier to weld in without anything in the way. That way you won't have to wonder if it will crack. With the kit, and your work that you already have in there, it should never crack.
     
  7. KevinsK5

    KevinsK5 1/2 ton status Premium Member

    Joined:
    Jan 17, 2005
    Posts:
    257
    Likes Received:
    13
    Location:
    Golden, CO
    homemade brace pic

    Well I finally pulled the engine this weekend to seal it up and put a clutch in. That gave me plenty of room to brace the frame on the inside too.

    The frame looked good, no cracks yet. So what I did was cut a 4"x6" triangle (the long side is on the frame rail, short side is on the crossmember) out of the same 3/8" diamond plate that I used in front. I welded it in yesterday and burned it really good so it ain't goin anywhere. Now, will this be strong enough to keep it from cracking? It looks plenty strong to me, what do you guys think? Thanks, Kevin

    Oh yeah, I've been using 7018 rod on everything I've welded.

    P1010031.JPG
     
  8. jolane

    jolane 1/2 ton status

    Joined:
    May 27, 2004
    Posts:
    132
    Likes Received:
    0
    No idea on whether that would help or not. My guess, it will help a little, but probably not as much as a bolt in steering brace would have. I guess the bolt in brace is out of the question though. The bolt in brace reinforces the bolt locations themselves.

    I guess it will be a try it and see sort of thing.
    Joshua
     
  9. KevinsK5

    KevinsK5 1/2 ton status Premium Member

    Joined:
    Jan 17, 2005
    Posts:
    257
    Likes Received:
    13
    Location:
    Golden, CO
    I was under the impression that the frame would flex and crack under high load conditions, just becuase there wasn't much there to keep it from flexing. Thats why I triangulated it on both sides. I sure hope the braces I put in serve the purpose. DoI have to worry about tearing the bolt holes out too?Thanks Joshua. Kevin
     
  10. Cricket

    Cricket 3/4 ton status

    Joined:
    Nov 29, 2004
    Posts:
    8,224
    Likes Received:
    0
    Location:
    Colorado
    Chevy steering is push-pull so all the stress is at the box mounts. Cracks usually develop at the bolt holes.
     
  11. jolane

    jolane 1/2 ton status

    Joined:
    May 27, 2004
    Posts:
    132
    Likes Received:
    0
    Yeah, what he said. The weld in braces cover the holes and effectively add another "layer" of support to the bolt holes (and therefore the steering box mounting locations). You can think about it like this: The force is transmitted to the frame through the bolts. The force is then distributed throughout the frame from the bolts to the surrounds steel. The highest load is at the bolt holes.

    This is why the bolt-in brace is so effective, it directly opposes the loads where they are the highest.

    I am not sure whether the cracking problem is one of overstressing (yield strength surpassed) or fatigue (repeated loading and unloading with sub-yield strength). It is probably a combination of the two, and a large force finally breaks the fatigued metal.

    If I was in your position, I would (actually I already have) put a weld-in kit in while it is still apart and call that good. I also have a bolt in brace. If it was my truck, in all honesty, I would also add the bolt-in brace and cut your gusset as required to make it fit. Again, this would be my plan of action, what you have might be just fine also...no guarantee either way.

    Joshua
     

Share This Page