Serpentine belt bearings, are dust covers important?

[genphreak]

Hello all,

Several times now when replacing fan belt bearings (item 3 and 6 below), I've found that OEM 'replacement' bearings are not designed to accept the factory dust covers.




Out of 4 or so new ones I order there is invariably one. The e36 I did yesterday was no exception.

I'm not sure if they are well enough sealed if left bare in such a dusty location.

What is your experience?

- Is there a way to buy aftermarket bearings machined to take dust-covers? I.e. like buying from a certain manufacturer or supplier?

Cheers, Nick