How to deal with cut subframe

Discussion in 'Disassembling and prepping' started by Jonathan O'Hara, Jan 28, 2018.

  1. Hi all,

    I had a fight with my passenger side control arm rear bolt 200k miles in salty Canadian winters, I actually feel like I got off easy). The bolt snapped and was very seized in the bushing sleeve. To separate the subframe from the frame (and from the seized sleeve/bolt) I cut the subframe to get my cut off wheel in and cut the sleeve/bolt. It worked, but now I need to figure out what to do about the subframe. I think main options are (and I'm open to better ones!):

    1. Mig weld the folded piece back in (recognizing that I'm a very novice welder and that steel is about the very top end of what my welder can do)

    2. As above, plus weld a 1/8 plate over the area to reinforce it (I worry the extra thickness might through off steering/suspension geometry?)

    3. Buy a (relatively) intact junkyard subframe (probably like C$120 or so)

    I really want to do #1 or #2 but don't want to set myself up for a catastrophic failure.

    Thanks for the feedback!

    Here's a pic of what I'm working from:

     
  2. Dreamer

    Dreamer Member

    Without a doubt buy one. Even if I were a master welder I wouldn't want to have any chance of a weak spot on a part as crucial as that.
     
  3. AleX1/9

    AleX1/9 Well-Known Member

    I would also recommend finding another one, especially it's otherwise pretty crusty
     
  4. RichRich

    RichRich Active Member

    Not sure what donor you are using but you can use a subframe from any model and year cobalt. Only difference will be the mount for the sway bar.
     
  5. All right, thanks for the feedback guys, to the junkyard I go to get a replacement, especially since they seem reasonably cheap, like C$100 - C$150.
     
  6. My donor has the FE5 "performance ride" suspension. What are the differences in mounting the sway bar to the subframe, and will they be a problem?
     
  7. Tony

    Tony Well-Known Member

  8. Awesome, thanks! I love that our forum has that info and sorry I missed it. I kept researching and post #2 in this CobaltSS thread: https://www.cobaltss.net/forums/suspension-67/upgrading-fe1-fe5-319672/, suggests that you could just drill a second hole in the FE1 or FE3 engine cradle to mount the 2 bolt sway bar clamps from the FE5. I think I've got a line on a reasonably cheap local FE5 cradle, so I may not have to find out if that's right.
     
  9. RichRich

    RichRich Active Member

    sweet, always easier if you can get a matching part. I was thinking about welding it on, so could too that route as well if it doesn't work out.
     

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