so this is a diagram you are pointing out

722.6 transmission leak

The no.30 part is a round seal in the transmission, and that linkage on it is not brass, its electroplated steel.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)