Failed Shock Mount

Jim Craik

Lifetime Supporter
Yesterday, Frances and I took the 40 down Skyline Blvd to Alices for Dinner, on the way home, it felt a little "odd".

When I got out, the right rear was sitting 1 to 2 inches low. The top, right, rear coil over shock mount has failed.

The top front part of the Upside down U shaped mount had failed with a clean break, approx 1' below the shock mounting bolt. The rear half held, but it has twisted up and to the rear, bending the sway bar as well.

This does not appear to be a weld, it seems that the fairly thin piece of sheet steel broke clean. (I'll try and post photos when I get home).

I have approximately 28,000 miles on her, but I do not remember hitting anything hard, and certinally no hard driving with Fran in the car.

Has anyone run into this before?

The piece that failed appears to be an intragal part of the tub.

I imagine a weld, with a new piece either welded over, or bolted over would probably fix this..........

Does anyone have any thoughts?:cry:
 

Seymour Snerd

Lifetime Supporter
Jim --

Very interesting.... could you post a photo or two?

If I'm understanding the failure location correctly, its where a bolt goes through the two frame ears and the shock from the front, and screws into the anti-roll bar pivot (IOW, there is no conventional nut). I can imagine if that bolt were loose the anti-roll bar forces since they are cantilevered through the mount, could cause a failure like that. It's all rather thin sheet metal and depends on everything being tightened down properly.

Thanks,

Alan.
 

Jim Craik

Lifetime Supporter
Another photo

mail
 
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Rick Muck- Mark IV

GT40s Sponsor
Supporter
Jim,

Broken links, no photos. Are these on a hosting site or uploaded?

28,000 miles!!!! Go Bless you brother, that is what these are for, driving, not parking!
 
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Jim Craik

Lifetime Supporter
Molleur,

Yea, I feel lucky, if the other side had failed, the shock/spring would have gone through the body and the tub would have dropped to the ground with a resulting loss of control!

I looked at the sway bar mount, it appears tight, but I will do further investigation.
 

Seymour Snerd

Lifetime Supporter
Here are some shots of the same are of P2160 showing how this is constructed.
RHS R Shock mount from front.jpg
The above shows that where Jim's broke was originally a continuous piece of sheet metal.
RHS R Shockmount from right rear.jpg
The above shows the construction on the inside with the shock removed; there's a rectangular wall tacked and spot welded into the inverted U that supports the shock.
RHS R Shockmount from left.jpg
From the opposide of the the one above.

I think if that shock mount bolt were loose this would all look very different from the way Jim's looks, although maybe if it were just a little loose it would allow the metal to flex along the line where it broke.
 
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Dimi Terleckyj

Lifetime Supporter
Hi Jim

Looking at the way it broke the best way to fix it would be to reweld the mount back in place and then make triangular plates to tie the three bolts in the photo together on either side of the mount.

This would provide all the reinforcement you should ever need.

Do both sides of the car as a safeguard for the future.

Dimi
 

Steve C

Steve
GT40s Supporter
Jim,

Take a look in the SPF Forum Page 1 under "Upgrades & Mods to P2125

Look at pics in posts 51 and 52 for how my sway bar is connected and the strengthening plate that helps support the shock mount ect.

Helpful?

Steve P2125

PS: Just looked at Dimi's post above....His suggestion is similar to what we did at time of P2125's original build;added the pate as shown
 

Jim Craik

Lifetime Supporter
Alan, thanks!

Dimi, yes, I noted the three bolts appear to have good spacing for a reinforcing plate both sides, of shock, both sides of car.

I just wonder if the sway bar bolt will be long enough?

Steve, thanks for the info, I'll check it out.
 
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