I've logged many hours on my Challenger machine over the past three years but I'm detecting a whine or squeel from my machine which seems to be comming from the mechenism below the motor. Are there bearings I need to lubricate or replace to correct this?

I believe that the motor is sealed, but just to be sure, give Challenger a call at 877-446-5887. If Chris cannot give you a technically precise answer, ask if you can speak to Lee.