Any idea of the service interval on these bearings?

I looked in my maintenance guide and they aren't mentioned. Is the philosophy wait till they roar then do races and bearings? I have around 200k on my sd and I'm wondering if I should open them up to pack them. No grinding, just the inclination to over repair my beloved car.

Maybe I should just be happy and keep motoring down the road?

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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