That's what I'm guessing, I don't know what else it could be. It doesn't easily go into gear without the clutch pressed in so the synchros do work but it feels like the shifter doesn't fully engage 3rd. It could also be a bent shift fork. It will go into 3rd fully and not pop out but half the time when you hold it in third it will still kick out of gear when I floor it. If it stays like this it will likely break soon, I'm wondering if I have a tooth missing or something causing the engagement issue. I will try to put some new trans fluid maybe something thicker like lucas for the hell of it, current gear oil in it is not old but it is just the stuff from the barrel we sold at Mazda (golden west).