I am working on a Bosch 11 227E (611227 139) The diagram is not clear on which way part #154 goes into the machine. I presently have it so that the larger end is facing the tool holder end of the drill, as opposed to the crankshaft. Something tells me that I have it backwards. When I took it apart, it seemed that it was held in with old grease. It sits in kind of a cradle, but I see nothing that keeps it from moving. Am I OK?