I have a 1983 300D and I have been having the most painful experience attempting to get the inside allen wrench bolt out( It is the one closest to the engine). I have looked everywhere, DIY mercedesshop.com, the dieselbenzwiki, everywhere , but no where really addresses how to remove that hard-to get bolt. I have everything else out up till this point but that one. I am trying to steer clear of jacking the bottom of the engine up with boards if it can be avoided. If anyone has any knowledge or has repaired this before and had the same problem, your advice would be GREATLY appreciated!!!