i have carrier central airconditioners (4) in my house. The fan motors on the outside with the compressor occasionally squeel and hang up - and the fan stops or won't start spinning. I can usually free it with a screw driver - and seems to run fine (for years).. I'm looking for a way to lubricate the fan motors. There are 4 holes above the fans that look like lubricating ports? Should/could I take the fan off and turn it upside down and spray lubricant "around" the shaft?