You look like you’re really close.

I don’t think that is called the lower control arm.

It’s called something like the guide rod mount. Anyhow it has a big rubber bushing and some captive nuts that can get really corroded up in there. You should disassemble it and see what is going on.

PeachPartsWiki: Suspension Bearing Bracket guide rod mount replacement

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79 300TD “Old Smokey” AKA “The Mistake” (SOLD)
82 240D stick shift 335k miles (SOLD)
82 300SD 300k miles
85 300D Turbodiesel 170k miles
97 C280 147k miles