Too much lightness?

[BobDrye]

Here are a couple of pictures of the front suspension of a 1999 Mercedes S420 front upper spring perch that are prone to failure. This Mercedes was towed to us as the coil spring popped out and was missing. We measured the thickness of the new part and the thickness is 1 mm! Am I missing something here? The static load on the part has to be over 1200 pounds.

[Hank]

That looks like a lot of surface area to dissipate the vertical force. I would hope some FEA went into designing that part. Since it is a Mercedes part I'm sure the Germans did the analysis. Where do they normally fail? The perch itself or does it fail at the interaction between the perch and the unibody?

[BobDrye]

This picture is from the driver's side that had not failed yet. Most of the square tubing used in a 7 is 16 gauge, this spring perch is 19 gauge. 7evin and I have experienced failures in the 16 gauge tubing in a 7.

[MHKflyer52]

Other factors look like a lot of corrosion at the seams.

[slngsht]

hard to believe that much rust on a 99 MB. I think they learned a few things from Chrysler too :lol:

[BobDrye]

We've done a number of S420's. The mount flexes, the seams crack, moisture gets in, and the rust starts. Most of the time there is no rust on other parts of the Merc. We reinforce the mount, then seal, paint. You can actually take your hand and flex the mount before we stiffen it up.