On the 3.0 gas I considered trying that. The cap on the back has I think four screws that’s will be pretty tricky to remove but I never tried access from below with the stiffening plate off.

It’s actually not very difficult to remove the alternator, remove the fan & shroud to give yourself working room.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)