fan noise

the fan in my stock (see sig) just got a whole lot louder than it has been, once you get over 1.5 k you hear it spinning allot, then once you get over 2 it sounds like an 18wheeler and it makes allot of noise. i can barely hear my exhaust over it. and its all rpm dependant. the worst is when you shift at 2 and you hear it slow down. i hate it, it never did this before,it just started last night. my fan looks like there are tiny cracks in it that go from anywhere from a quarter of an inch long to over an inch, but it still looks stable. if the motor is off and you turn the fan by hand then it seems hard to turn by itself. i hope you all have enough details for now. letme know whati can do. im gonna have somewhere look at it sometime. now is the time to go electric?