Need guidance.

According to ZF Hurth Marine’s Operating Manual, the fluid filter on a ZF 45 C (direct drive application) transmission is located on the underside of the transmission housing. At least that’s the way it’s shown in the picture.

Running my fingers along the underside surface of the housing, I have tried in vain to locate the two bolts that hold the filter cover and seal in place. Nothing there. Zip. Zero. Completely smooth surface.

Direction on locating the filter would be appreciated. Thanks!