Today, I had to return a few items at Sear, so I grabbed a 10mm hex socket and 20" extension bar. However, I did not get back to work; I'll give it a whirl tomorrow.
The symptom, anyhow, is that the starter does not crank. Once every other week, or so, the solenoid clicks but nothing else happens. Disturbances ranging from the hood closing to hammer impacts will correct the problem until ~10 days later. I believe that there is either a loose connection between the solenoid and motor OR that there is a dead spot in the motor. When the brushes are worn, would the motor work intermittently?