Eric,

I have a "standard" edition 1982 240D and have no real problems getting a 27mm socket and a short extension on a 1/2" ratchet to turn the crank. I put the extension on the socket and fit that to the crank fastener, and then put the ratchet on, all from above.

That said, I did this job (valve adjustment) on my Father-in-law's 1980 240D while up at the family camp at Lake Champlain a few years ago, and did not have a 27 mm socket. So, I parked the car facing downhill (on a very slight incline), put it in gear (4th) and just pushed the car to move the valves, then used a stone to block the wheel. It worked so well I do that way most of the time. I will confess I have used the power steering pulley fastener a few times too. Anyway, the push the car method gets the job done in about a car length. I push it back in neutral, and check in another car length, just to avoid dragging my tools down the driveway.

So, unless you have the forearms of Popeye, or grizzly bear claws for hands, or both, there is no real reason you cannot get a socket on the hex at the end of the crankshaft to turn it. It should also be noted though, there are a number of other means as well, many of which are practical and technically sound. Good Luck, Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)