W124 1995 E320 Rusted Shock Mount
 

One of my rear shock mounts is heavily rusted.


I am wondering if I should either:

1. Remove all rust and patch with JB Weld.
2. Remove all rust and weld in new steel.
3. Never replace the shock and scrap the car when things get too bad.
4. A better idea from some one else.

There is enough steel remaining so that the car is driveable, but maybe not after I pull out the shock.


Any thoughts or recommendations?

I'd aim for option 2

Although the areas look small it looks pretty grim because that is delaminated rust => i.e. rot

I'd expect to see some alarmingly large holes after you've removed the rust.

Attack it with an angle grinder with a wire brush - be rough - try to break the area

As you suggest in one of your options this is a critical component - a shock absorber letting go at an inconvenient moment could be catastrophic

Option 2 would be the best by far.

Good luck!!!

The thing about welding is that I would have to remind myself how to weld after 18 years. I highly doubt the car is worth enough money to pay for this welding.

Where do I buy the steel? I suppose there is a particular grade that would be needed?

Or can I buy this section of the car (new, not from Mercedes)?

You need to get some mild steel sheet of the appropriate thickness. Most of it close to that area will be about 1mm thick but there's (almost certainly) some sort of strengthening gusset there too that needs to be fixed.


Companies such as Klokkerholm might make repair panels: You'd have to search. They won't be cheap - they won't be cheap to fit.



"Worth" is an emotional variable - this repair is going to be a big one - from what you've shown I imagine it might take as much as a day to fix those bits. What does the car mean to you? Do you want to "save" it?

Perhaps a cut of that section plus a margin of a couple of inches of clean rust free metal from a donor car taken to a welder would work.

Good luck!!!

First, some clarification. From a structural perspective, it isn’t that critical. The spring mounts take most of the load in the rear. As long as the wheel doesn’t drop too far, like from a massive pothole, the spring should stay in place if the top shock mount fails.

Second, I would expect a local welder could do a good job for not too much money if you don’t want to tackle yourself. You do the prep and access (and keep a fire blanket over the gas tank, and do it outside so you don’t take the garage with you if it goes up in flames).