02 T&C alternator squeaking?

My mommyvan alt is making a chirping sound , varies with engine speed. Dont know if it is the bearings or that stupid one way sprag "coupler" on the end that seems to work when I took it off to test, only rotates one way and locks when reversed. Can you lube these bearings without taking off that pulley/coupler or what? Coupler is $60 alone, rebuilt alt is like $180! charges fine, just makes a squeaking sound...