I have done this twice on my Volvo Diesel. As others have mentione I put blue Loctite on the (cleaned and degreased with brake cleaner) threads and after threading the bolt in as fare as it would go by hand used an impact wrench to tighten it down. (On the Volvo you have to do the every time you change the timing belt.)
The other way is if you can get inside the crankcase with a bolck of wood; rotate one of the Crankshaft until you can pin the block of wood against the crankcase and torque to bolt down. I have never had the little oil pan off of my Mercedes to know if there is enough room to do this or not.

__________________
84 300D, 82 Volvo 244Gl Diesel