Sheave cover and o-ring

I just ordered a sheave for my 2012 700 Rhino, it should arrive today or tommorow. I have been watching the videos on greasing and installing the sheave. I am a little confused. Do I need to install the cover and o-ring on the sheave or is this part left off on the new machined sheave? The video on greasing the sheave does not show the cover being re-installed and the installation video shows a machined sheave being installed without the cover. I searched and found on here that if using grease the cover should be intstalled. I am a little confused, to cover or not to cover? I just want a definite answer. Any tips and or advice would be greatly appriciated. Thanks.

cover and use o ring when using the grease

If you are using grease, you have to use the cover and o-ring.

Thanks for the info.

Installed the sheave today. It really put some pep in the rhino! I was a little skeptical at first, but James made a believer out of me. Something actually happens when I press the accelerator now!!! Very happy! Thanks.