First, i dont know what a pinion on a harley is. I do know what a ring and pinion on a car rear end is,, but, any way, ive been having trouble with the bike starting when hot, so i took it to harley while still under warranty,(07 e-glide ) and they called and said the pinion gear was all chewed up.. Said,, they had a problem with them on the 07s , and something to do with the torque specs, and i have no idea what the are talking about. So hte are replacing it under warranty with the right specs??? Bike has 16000 miles

 

It's the gear on the starter that engages the ring gear on the clutch basket to start the engine.

 

they have had that problem there are rumors of a recall the starter bolts come loose or orent tight enough from factory causing starter gear to improperly engage ring gear on clutch and in some cases oil leaks from primary that can short the starter