The front (drive end) bearing would almost certainly be the source of your "light whirring noise" then Bob.
Strange as it may sound, that will be effecting the output, all down to the magnetic fields in the rotor and stator and will also cause it to get hot.
__________________
Cheers
Dave
Next Door to Top-Gun with a Honda CR-V & S Type Jag  Volvo gone but not forgotten........
|