You have described the correct approach, however if enough access behind you can drill the stud out completely and fit a longer bolt right through as long as enough room to hold it with a spanner when you do the nut up.
The soundest way (and most probably, most economical way) to repair that broken stud would be to get a body-shop to remove the small panel that both the studs come through (and are welded to), replace the stud with the apropriate screw (8mm x 1.25mm thread) and then weld the panel back in. New rear cross-members are available (Axel Gerstl can supply one for just under E120, but then you also have to cost in getting the panel painted. Being that panel not only supports the engine but also stiffens up the rear of the car, I would suggest that it is not "bodged" in any way at all.
What I suggested was in no way a bodge, especially the engineering process of drilling and tapping and was only suggested as the contributor said they
I was not infereing that your suggested method of repair was a "bodge" bugsymike, just pointing out the reason for doing a "proper and sound" repair, and an alternative approach to the problem. Also, not everybody who has a 500 (or ANY classic care come to that) has access to 'taps and dies'. I work in a "Classic Car" garage and you would be amazed how "non-mechanical" some of our customers are, and incapable of doing even the simplest of maintenance jobs on their 'Classic'!
Sorry I bite sometimes
.Apology accepted Mike----I too find it difficult to balance the "sucking eggs" and 'gently'pointing out , what to you, me and some others on the forum is "bleeding obvious". Yes, the 'classic car' garage is very interesting, if not somewhat frustrating, at times. About 25% of our work is unpicking the work of the "enthusiastic amateur"! I got fed-up with retirement, so "retired from retirement", and being that I served my apprenticeship in a M/Benz dealership and built racing-cars for a time, going back into the 'classic car' world helps keep the bits between my ears, and my digits all working.Sorry I bite sometimes
Something I have found with the Forum I find, is the wide variety of skill levels and getting the balance between teaching "granny to suck eggs" and expressing something I find easy, yet someone else is totally lost with.
Your "Classic Car" garage sounds quite rewarding.
Well done!----a really neat repair
Yes neat, something like what I meant in my original advise.
Upon closer inspection, I agree with Mike---if there is any weld protruding around the base of the new stud you will probably have to put a large (central hole) washer around the weld and then put a similar thickness washer on the other 3 studs to match, in order that the rear cross-member pulls on 'square'. If there is a plate, you will just need the matching thickness washers on the other 3 studs. If you DO have to do that,you may need to slightly adjust the gear-change---the 2 bolts on the right side of the central tunnel adjacent to the gear-lever are the adjusting bolts for the gear-lever 'box'.Yes neat, something like what I meant in my original advise.
Is it my eyes or is there more metal plate this side of that repair which may cause a slight misalignment with panel lines on assembly? Though as you say with the paint nobody will see it?
Optical illusion. Lined up and installed perfectly.Yes neat, something like what I meant in my original advise.
Is it my eyes or is there more metal plate this side of that repair which may cause a slight misalignment with panel lines on assembly? Though as you say with the paint nobody will see it?
When I initially welded the stud in, there was some excess material, but I used a Dremel with a side cut rotary bit and smoothed it all down to the base metal before painting it.
