Does paper feed roller shaft drive wheel need to be timed?

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.