your reverse missing more sounds like the clutch drum behind the front pump - I think its called the K3. It also plays a role in 1st gear I believe.

Stretch has a nice chart for this.

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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)