My blower motor works on all speeds, heat and AC, but will always make a grinding/rubbing noise, even to the point where it sounds like it's not spinning as it should be. I have taken it apart, checked for snugness of fit, debris spurs on the fan itself as well as the shaft it goes into. Also, when putting it back together I have ensured that all 4 screws are tight without being overly so. So, need to know if there is a quick and cheap fix so this sucker will work without the aggravating noise and grinding/rubbing.