oh yes thats a nasty surprise when they lock in the open position. The driver door gets most wear - so its not unusual for them to fail.

if you want to apply some grease then dont grease the tongue, the grease should be aimed at the cavity below and above the tongue so that the balls get a bit of grease.

Also make sure the water protection sleeves are installed on them, they are black plastic covers on the inside. If you are missing those then rainwater can get in them and destroy the grease eventually seizing the mechanicsm.

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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)