Front Sub Frame - Bend or Break
#1
Advanced
Thread Starter
Front Sub Frame - Bend or Break
Hello,
I am working to putting back together a C6 base that had some forceful unplanned bodywork done to the front end (:cough: an accident :cough: )
Passenger frame rail was bent, and it was bent straight up. Replaced the frame rail and measured everything 12 times it felt like and it measures within 1mm in every direction, and left matches right as well.
Went to put the drive train back in last night and front sub frame is not lining up with the mounting bolts in the frame rail (probably off by about 3/4 of an inch )
After calming down that the frame rail was in the wrong place, and remeasuring the frame rail, which still is measuring within 1mm) and matching top and bottom no matter how i measure, i started looking at the sub frame.
If i measure from rear mounting hole on front sub to front mounting hole on the rear, the left is off by roughly 3/4 of an inch found the problem....
Now the question, my understanding is these sub frames are aluminum, and aluminum likes to crack and not bend. I do not see any cracks, or bends, to the naked eye it looks as straight as an arrow. Is it possible to have a bent sub frame, and have no stress lines, cracks or wrinkles?
I am working to putting back together a C6 base that had some forceful unplanned bodywork done to the front end (:cough: an accident :cough: )
Passenger frame rail was bent, and it was bent straight up. Replaced the frame rail and measured everything 12 times it felt like and it measures within 1mm in every direction, and left matches right as well.
Went to put the drive train back in last night and front sub frame is not lining up with the mounting bolts in the frame rail (probably off by about 3/4 of an inch )
After calming down that the frame rail was in the wrong place, and remeasuring the frame rail, which still is measuring within 1mm) and matching top and bottom no matter how i measure, i started looking at the sub frame.
If i measure from rear mounting hole on front sub to front mounting hole on the rear, the left is off by roughly 3/4 of an inch found the problem....
Now the question, my understanding is these sub frames are aluminum, and aluminum likes to crack and not bend. I do not see any cracks, or bends, to the naked eye it looks as straight as an arrow. Is it possible to have a bent sub frame, and have no stress lines, cracks or wrinkles?
Last edited by Hellbringer; 05-03-2017 at 11:01 AM.
#4
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Thread Starter
I am pretty sure mine is aluminum, I use magnets to locate centers of holes when measuring, and my magnets do not stick to the sub.
#5
Safety Car
09LS3 was confused about what you were referring to. What he said is correct about frames. You're talking about the engine cradle, however. I'm not sure if they would bend or break.
#6
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Thread Starter
#7
Drifting
The engine cradle will bend to a certain point before cracking. If the frame rail was bent as bad as you said then the cradle bent too. It would be better to replace the cradle because once that aluminum bends like that it will crack and break if you make an attempt to straighten it. If it does not crack when you straighten it, the stress point will be so weak that eventually it will break and you could have a mess on your hands.
#8
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C6 of Year Finalist (performance mods) 2019
The engine cradle will bend to a certain point before cracking. If the frame rail was bent as bad as you said then the cradle bent too. It would be better to replace the cradle because once that aluminum bends like that it will crack and break if you make an attempt to straighten it. If it does not crack when you straighten it, the stress point will be so weak that eventually it will break and you could have a mess on your hands.
I'd suggest finding another undamaged cradle to verify the mounting measurements will match your current frame attachment points, since it sounds like the frame was also stretched.