grinding noise in my rear shock/swing arm

There is grinding nosie in my rear shock/ swing arm. It sounds like rocks are grinding or something. It only happens when I sit on the bike and compress the rear and release it back up. I think maybe the the rear shock is done for, but i'm not sure. Any help would be great, i'm going to the desert and plan on riding through it and taking care of it when I get back. Bad idea? Let me know. Thx.