The drive gearwheel on the feedroller shaft has its boss split and stripped as the wheel has turned on the shaft. I have made brass attachments which sandwich the wheel and made a sleeve to hold the boss together. I now have a very strong wheel with a second boss on the other (out) side, two grubscrews 90 degrees apart affix it firmly to the roller shaft. What I need to know is, I notice the PG disc glued to the gearwheel, which is read by an optocoupler, and which has its outer circle of radial stripes for that purpose, also has 1 to 12 marked around on an inner circle, and at the 12 there is a rectangular opaque blob which suggests that there may be a "second track" on the disc read by a second part of the opto. OR this circle with the 1 to 12 may be read in the factory by a strobe device to check the vertical registration. If the above is too confusing, my simple question is, when I fit the gear to the paper feed roller shaft, do I need to worry about the timing. Do I just fit it and it will work.