For those of you who didn't understand what I was trying to explain, I posted a video.
http://www.youtube.com/watch?v=34Hnd6FftW4
RC4WD sent a second replacement motor. It ran fine for a few minutes, then began to slip. Some where along the line the set screws were kicked out. I did a little drilling and used some cone point set screws. The problem seems to be fixed, so far.
The bell housing seems to be press fit on the shaft. The set screws do little more than fill the holes. It's not an easy task to disassemble the motor.
Thank you all for your suggestions and comments.