I found that one of my 85 300D's jack points has rust on surrounding rocker metal.

I posted a picture in a thread in Bodywork forum.

I have not used those jack points for years. I use floor jack and could put bottle jack in car in place of MB jack. Do any of you that own old W123s still use the jack points? They always seem a bit suspect.

I had the front passenger side weld repaired last fall and , and another pic and here is finished repair. The current one is on same side at rear. In two minds whether to have my welding guy fab new piece of plate and weld it in. Based on the front one, the internal structure is likely quite strong and would probably still lift car. But that outside rust needs to be repaired. I could use POR15 to seal rust and then lay up an epoxy/glass surround. Welding would no doubt be best, but hard to justify.

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

I never have, and also have the same kind of idea as you.

Im intending to cut 4 patches out of the center of the rocker on a parts car, and cut out the jack points and have the patches welded in.

IMO the jack points do absolutely nothing but rust heavily, and this is my plan to eliminate this endless rust problem once and for all. All 4 of mine are getting pretty soft around the hole

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Yes. It leaves space open for stands.

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1982 300CD Petrol/Black Leather

I have always used the jack points. never really thought of doing otherwise. Mine are in good shape, and the one that was not good I put all new metal in. made it out of stainless that I formed to fit.

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1977 240D turbo

I keep mine sealed with plastic corks and insert a vary large bolt as a lift point.

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It's the metal around the tubes that rusts out it seems. The plugs only keep the inside of the tube dry and free of dirt. Not sure why the rocker metal rusts. Maybe water gets under the paint or undercoating where the tube protrudes.

Regarding lifting, I lift on or near the front subframe mounts - there is room for jack and stands. For rear, if I want both sides raised, I lift under diff and then put jack stands at subframe mounts. I wouldn't put jackstands under the rockers on a car of this age

Starting to think that filling jack holes, then fairing in over depression around tubes so rockers are smooth on outside may be an option. That would perhaps solve one rust problem!

47dodge said Did you weld stainless to the steel rockers?

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

I use mine all the time, I don't trust crawling under the car with just the jack and a tire lifted....but I have used them numerous times, to jack the car up and place a stand under it....even if I just need a lift extra room to see something under the car I use it....I love the jack points, so much nicer then the bumper jack found on may 70s and pre American cars.....now that is a scary way to replace a tire!

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X2 I use the original jack in the jacking points but always use chocks and jackstands for insurance.

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Codifex
1981 240D ChinaBlue (Got her running with a donor engine.)
1983 300DTurbo w/sunroof.
1984 300TD manual sunroof. (Electrical Gremlins)

Always used them when I had a 123; always use them when I lift the 124 and 210. However, I then put a jack stand under the pad and take most of the tension off of the jack. The jack remains in the jacking point as a backup and as a convenient place to "store" it until time to take the car down.

Jeremy

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

What is "rust"?

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CENSORED due to not family friendly words

grrrrrrrrrrrrrrrrrrrrrrrr!!!!!!!!!!!!!

{jealous}

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

x3 I do the same.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Watch out using plugs. My cousin in Germany (who used to work for Mercedes and has seen a million of them age) warned me that plugs had a tendency to trap moisture and actually cause rust rather than prevent it. Personally, I like the finished look of the factory plugs, so I just try to keep the holes dry and greased.

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1982 300CD Petrol/Black Leather

How many people use them for a tire change? Curious, sounds like lots of people use them to lift to put the car on stands

For that I use a big floor jack, then jack stands like above.

I have a small floor jack, a sheet of aluminum, plus a 4 way tire iron I keep in the trunk for blown tires. Much more effective than the stock jack, and eliminates the potential for the jack rotating in the hole

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This post brought to you by Carl's Jr.

So far, looks like those in dry climates are more inclined to use the jack points.

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5