I know it is 17mm, but the 2 bolts on either end of the motor have no room to put a regular type socket on it..they are up tight against the block..also an open ended wrench just slips off..
take the seal carriers off, then you can get ANYTHING in there..
i use a grinder on a OLD 17mm socket.. taking off material one the 1 side of it will let you do this no issue..
Thanks, so simple a solution and I should have known..it has been many years since I took one completely apart and forgot about the end covers and since this block is so covered with heavy oil/grease those little bolts can not be seen..