You need to tell us WHICH rifle for us to give you an answer that has any real meaning. Sorry- good questions= good answers.
Contact the maker.
Contact the maker.
Try e-gunparts.com
You will have to take it apart. Each model is different so you will have to find a diagram of the rifle.
How to find diagram for removing rear drum from a 2002 Cavalier
Follow the link below to the parts diagram from the Numrich Arms website.
I suggest that you go to the Crosman homepage ( they own Benjamin) and click on "Download a manual" there you will find the owners manual and parts diagram for your rifle. See related link.
Try midwestgunworks.com
I would contact Daisy directly at the link below and ask them.
Gun show, want ad, gun shop
Go to some Forums and look. You find that it is the same breakdown for most of the Dana axles. A good one to go to would be pirate4x4.com
Down below is a link to a diagram that I hope you find useful.