C3 Front lower crossmember strength

[Eric Fairclough]

Hello, I have heared that the lower front crossmember is a weak spot on c3's. Apparently the weld eventually cracks and then the lower control arms start to pull out and the best way to prevent this is to get it welded better then put a spreader bar on it to prevent flexing. Has anyone experienced this problem or tried to prevent this? My cross member is dented in the middle from previous owners jacking the front up with a floor jack but it is not coming apart. Thanks Eric

1972

[Jack H.]

Re: C3 Front lower crossmember strength

Haven't seen front cross members pulling apart on well cared for, un-rotted, frames.... We've serviced lots of C3's over the years at our shop in Denver....

On the center plate being dented by prior mechanic jacking of the car, this is a COMMON issue. This was NOT a legitimate jacking point. You'll find Paragon lists a replacement plate to weld over the existing plate and/or use to replace the original.

[Eric Fairclough]

Re: C3 Front lower crossmember strength

Jack, Where is the best place to jack up the front? Is it best to only jack one side at a time under the control arm?

Thanks Eric

[Brian Monticello]

Re: C3 Front lower crossmember strength

I use a small piece of 2x4 reinforced with a steel plate (on the jack side). The wood block gets placed between the bumper brackets and placed perpendicular to the cross member. I had to shave off some wood to get it to fit between the bumper brackets.

I needed a place to lift the car at one point for use on a sliding jack tray ona 4 post lift. There is no way I would lift side by side on a 4 post lift!

I got the piece of steel at Menards for $5

Brian

[Dick W.]

Re: C3 Front lower crossmember strength

Eric, the only cracked frames as you referenced that I have seen were on cars that had been raced hard over the years. I have never seen cracks on a normal driver.

[William Holder]

Re: C3 Front lower crossmember strength

Erick this is common on later model frames like 75-77- and newer they were thinner metal and welded very poorly I am not sure but always guessed that this was when they started using robot weldors. Sometimes the welds will not even be on top of the seam! I am not sure what years this was a problem but 68 and 69's seem to be OK
Just FYI
Bill