Gear streak or not?
Gear streak or not?
Are you sure it's a gear streak?
The only reason I ask, is I have seen many streaks that look like gear streaks but actually turned out to be roller streaks.
Many times it was due to a rubber roller being set too tight or that it lost part of it's bonding to a roller core, which caused the rubber to wrinkle when turning against an oscillating roller, which will transfer all the way to the printed sheet and look like a gear tooth pattern. Even a new roller can do this if there is a defect in the bonding to the core, or if it is just set too tight.
I have seen this issue on a variety of machines, I think they are all susceptible. In the past I have inked the unit up with a dark color, Black or Cyan, let it tack up a little bit, and just let it run at printing speed, then look at the surface of the rollers as they turn with a bright flashlight. If you see any "patterns" in the ink, this may be your problem.
You may indeed have a mechanical problem, but it's just a thought.
