Investigating a starting issue I've had since I bought the truck. Engine does not always crank (3/5 times probably) and the starter motor makes the usual noise and a very unpleasant sound in addition. My thought was the flywheel is not being properly engaged and metal is clashing.

I suspected the starter and solenoid and removed them after doing a basic voltage check (no voltage drop test which I should have done...) and was getting 12.4x volts at the starter so I thought 'good enough'.

Once off the vehicle tested with jumper cables and saw the gear was extending fully and spinning quickly. As far as I know - good result.

Wired the starter back to the vehicle and took the footage below. Even when attached to the vehicle the starter gear seems to engage properly. Not easy to see in the video but only the outermost end of the gear is worn along the face of the gear.

This makes me suspect a worn flywheel which I provided a small video of as well. I can definitely see some wear but in my opinion there should be enough teeth there for the starter gear to engage as long as it's fully extending.

My eye is not good enough to say if the flywheel is too badly worn (or starter gear for that matter) or not. I definitely see indications of wear but I imagine there's plenty of life left in the flywheel - but who knows.

partial flywheel inspection: http://1drv.ms/1QtJt1G
starter being engaged with key in ignition: http://1drv.ms/1QtJu5Q (ff 30 seconds)

Starter, solenoid, flywheel? Could it be that the simple fact of removing the starter from the vehicle in the first place dislodged something and now it's working just fine? Maybe it's still a voltage drop issue... Looking forward to your thoughts!