This is a ten-year old Goodman GMPN100-4.

Today the motor suddenly increased in noise. I went downstairs to look it over, and the sound level is very loud, coming from the motor/squirell cage area. I took off the door, reached in, wiggled the squirrel cage to see if it was loose, and it did not appear to be. When rotated by hand, slowly, I could not feel any abnormal resistance, and it turned freely, and appearently, quietly.

When I pushed the contact to watch it start, however, the cage began to rotate very loudly, and seemed to be out of balance. This runs off a 1/2 HP motor, with three mounts around the shaft, I believe.

So my question is: Is the motor bad, or is the squirrel cage bad?

I plan to call for professional service in the morning. I have found motors on-line varying from $125 to $289 for the motor (P/N B13400-20), and around $80 for the cage blower wheel (P/N B13680-47). I figure the service guy is probably going to charge me considerbly more, but if it an easy fix, I might try it myself first. However, I'm not sure to try replacing the motor first, or go for the wheel first.

What do you think? Do motor bearings go out, or is there something I have missed?

Thanks in advance for any opionons out there. It seems to be running OK, although it's running with a vibration now, and I hope it will hold out till morning.