if you mean the vertical shaft gear it is not to difficult as you only have to loosen the 2 screws on the gear to release it,sometime a little tap with a punch to loosen and slide down is needed.if you cant get to the screws drill a 5mm hole in the machine casing in line with screws.the horizontal gear is a lot off work cause you have to remove complete top shaft,possible but a lot of patience.the feed dog timing is correct when feed dog is at its lowest most rear position when needle touch needle plate on downward movement
johan, March 2012
