Building a trainer

[Tinbender]

I have yet another question for the guru's.

I was trying to set the stops on my radio last night and got that accomplished quite well. But when I turned on the truck to make sure of the shifting and steering, I got a buzz sound coming from the motor. I can feel it in the tranny but there is nothing but gears in there so it has to be coming from the motor. The last time I turned it on I did not have this noise but now I do. Any suggestions?