I replaced the pinion seal in my 280 project yesterday. Not having the holding spanner 111 589 02 07 00, I came up with this arrangement to keep the pinion from turning while I loosened and tightenend the slotted nut. It's a 10 mm bolt with three nuts. Two secure the bolt to the flange and the third butts up against one of the bolt heads on the cover. To tighten, I just moved the flange so that the third nut was against the bolt head below (obscured by brake cable).
