Third gear always grinds in a power shifting mode --- just third gear. I'm not sure if I created this over time or if this is a defect. I can go through third gear without the grind in a very soft shifting sequence. Any feedback is appreciated.

 

3rd Gear grind has become a typical occurence in the Z's tranny. If you can shift slowly and it doesn't grind, but when you shift quickly it grinds, it's a symptom that your 3rd gear synchro is failing. I'd get it into Nissan for analysis if you're still under warranty. And I wouldn't mention your "power-shifting" activities. That's very hard on the transmission and a difficult dealership could claim abuse and hassle you on warranty repairs.