i found out the hard way that there was two types of wedge, i found one type in my books, so i stoped looking, thought i was backing off the rears on the 977, hooked up to it , get out in the middel of the interesction , droped it, hooked up to the front so i could turn it around, went to bacbup, wont roll, didnt want to dink with it in the road (by this time traffic did look apon me as a postive thing), just rehooked up the rear and put it back in the same spot from where it started from.. then went in and READ the book to see what was wrong, on the NEXT page shows the OTHER type DA