LCA Mount - Stress cracks found

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LCA Mount - Stress cracks found

Postby kayak » Tue Feb 23, 2016 12:15 am

Doing the S-10 spindle swap and replacing front end components on wifey's 75 Skyhawk.

Was cleaning up the area, getting ready to reinstall the control arms (new bushings and ball joints in place) and noticed some ugly welding work done around the rearward mount for the lower control arm.

Then I looked carefully at the forward mount for the same LCA and found what I think are small cracks in the surfaces around the hole where the cam bolt drives through.

I imagine this area is under a lot of stress…as evidenced by the ugly weld job on the rearward mount. Since this car wasn't raced, I'm assuming age and mileage have taken their toll on this area.

I can certainly do an "ugly" weld job on the small cracks, but wanted to get some input before I fired up the Mig and laid down some ugly beads of molten metal wire.

Any thoughts?

Pic 1 - Passenger side, LCA mount.
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Pic 1 - Passenger side, LCA mount.
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Pic 2 - Ugly repair weld on LCA, rearward mount
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Pic 2 - Ugly repair weld on LCA, rearward mount
Pic2.jpg (236.16 KiB) Viewed 375 times


Pic 3 - Cracks on LCA, forward mount
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Pic 3 - Cracks on LCA, forward mount
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Pic 4 - Close up of cracks
Pic4CUSmall.jpg
PIc 4 - Close up of cracks
Pic4CUSmall.jpg (246.96 KiB) Viewed 375 times
1975 Buick Skyhawk (survivor)
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Re: LCA Mount - Stress cracks found

Postby 71GTKammback » Wed Feb 24, 2016 12:21 pm

Ugh indeed. I just had my monza towne coupe apart, i saw no cracks of any kind. 62k miles on the car
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Re: LCA Mount - Stress cracks found

Postby gt350fme » Thu Feb 25, 2016 12:36 pm

To me it looks like there was some kind of collision damage??
I would level the car at the door sills on a level surface and make lots of measurements where it matters comparing one side to the other to make sure things are equal and square first before cleaning things up and re welding.
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Re: LCA Mount - Stress cracks found

Postby Monza Harry » Thu Feb 25, 2016 4:16 pm

gt350fme wrote:To me it looks like there was some kind of collision damage??
I would level the car at the door sills on a level surface and make lots of measurements where it matters comparing one side to the other to make sure things are equal and square first before cleaning things up and re welding.

This is good advice! All I can add is to cut a "relief or dig it out" along that crack with a "Ball Burr" to improve penetration/fusion of the weld. I wouldn't go crazy as that isn't all that thick there to start out, it will also help with cleaning that crack out to reduce the chance of porosity. Is there enough room to re-enforce that crack? I would if I could. Harry
I'm not a hoarder I'm a preservationist 78 Monza Spyder (Soon To Be 2+2 with Spoilers)
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Re: LCA Mount - Stress cracks found

Postby mahoy78spyder » Thu Feb 25, 2016 6:56 pm

i've got the same issue... no pics to post because they're a pain on this site, but suffice it to say, I'm having to seriously consider drastic measures on how to either 'save' the front frame/suspension, or completely replace it with something aftermarket. :-(
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