S2-Kai

Not sure where to put this so I thought to try here. I have a scarred gear in my trans, it's a 350z trans that I am using to swap into my S. I noticed that 1 of the gears on the counter shaft is scarred, possibly from friction. However, there is nothing to support this on any of the other gears. There was also no excess shaving or chunks in the case. The gear I am talking about is the middle bottom one, you can clearly see vertical lines in it. They are on every teeth and don't seem to be very deep. Any ideas?

S2KPUDDYDAD

Could be just tooling makers when the gear was made.

MM3Kwolik

I have worked on very large reduction gear sets during my time in the Navy and that looks like marks that were caused by a very fine piece/sliver of the leading edge of a gear. I would rotate the shafts very slowly around to inspect every gear for damage aside from that damage. One thing you can do is separate the two shafts from each other and apply a very very light coating of Prussian Blue to the teeth all around 1 shaft, mesh them back together and slowly rotate it one full revolution being sure not to overlap and see how the gears are meshing. Chances are it was caused miles and miles ago and the piece(s) that caused it have all but disintegrated. Nothing I see in that picture will compromise those gears or the transmissions overall integrity.