My name is Scott Baue. My family and I own Leaders Edge. We rebuild rear ends for many teams for most of the classes of midgets and sprint cars. The lifespan left on your pinion depends on the motor you run and if you run wings and the quality of the grease you run and how often you change the grease. If you run wings, I would replace it immediately. Non wing with a thumper motor I would say you can get another 10 or so shows out of it without much worry. I would change the grease every night make sure you are running a quality grease.