is this the tool you are looking for?
If so, check with:
http://www.samstagsales.com/mercedes.htm
Scroll down to Steering, or search for "pully" (It's spelled that way on the website).
If it's not the right one, I'm sure calling would set you off in the right direction. I am getting ready to place an order with the site. I'll report back if you don't beat me to it.