When looking for a W123 or even a 126, what would be acceptable and unacceptable rust damage in assessing a used car to buy. It seems to me the usual rust points are at the jack holes and along the bottom of the rear fenders behind the wheels. I had an 83 24d manual (hit at a 4-way by a 17 yr old girl driving her new car from the dealership 343k, would have outlived me) that had that and it seemed the trouble came from water in the trunk .

Have tried to locate replacement metal and havent found any.

Im not bad at Mig welding and can patch a spot, but in your experiences, what type of damage just isnt worth the effort? It seems at the rear lower fender where it meets the inner trunk, looks like that might be a b*tch. My local repair shop has a nice '85 300 as a gopher that has rot at the rear, if they havent tried to fix it, it probably aint worth fixing huh?

I want to get a 300d and restore it to near mint. I know the scope of this but hey, I dont go out much, dont drink, no vices, (well, not many), not into clothes, accessories, hate golf, its the siren of the diesel that has me hooked. I dont look as it as work......BECAUSE IT ISNT!

Im sure you understand.

well... it depends upon the damage.. if the frame rail channels are heavily rusted out then i would start running.. LCA mount points... stuff like that.

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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

When buying I would reject any car with any rust other than that from paint chips. Common areas are the trunk sides, under the battery tray, hood hinge pockets, and rear floor boards. I had the battery tray and rear floor problem in my 240D. I fixed it the right way, but it was a pain. If you are buying a car, you may as well buy a good, solid example.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

If you want a near-mint car, spend the extra for one that doesn't have anything but paint-chip type rust. I bought a car that I knew had some rust, and has turned out to have more than I thought. Repair hasn't been too horrible (I'm about half there) because I'm not looking for a "mint-state" repair. Rust around the jack tubes was fixed by cutting out the rusty bits with a grinder, welding some plate over top, and covering with rubber undercoat spray. Effective, but not original-looking. Generally, fixing rust is more involved if the end result has to look like new. If that's the case, pay more and avoid having to do the repair in the first place.

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1982 240D automatic
Odometer quit at 307K...about 325K now

Look at the front sway bar mounts on a 126 inside the front fenderwell area.
I have one an 83 300SD with a case of prior owner #!#$@^#$@$% idiot syndrome. What happened to this car was the battery overflows and rots the tray and the sway bar mount area under it, if not maintained. Then the bar mount gets weak enough to break loose and proceed to beat the sheet metal out and around the area under the fender. So look for deformaties in this area
would be my advice.
You would think that the noise from this would keep a person from driving it right! My daughters bought this car and I have just finished with welding in a new sway bar mount area, what fun...
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