If you are talking about grease fittings, say on the driveshaft, you probably don't have any like me (2wd), I guess 4wd's came with them but not ours. I am still investigating the issue and am going to attempt to install some, or use a grease injection needle to get into the ujoints. Your suspension ball joints do however have fittings, or plugs where you can install fittings if noone has done the job before. You can get zerk fittings at about any autoparts store, big R, Tractor supply, etc. as well as grease guns and the appropriate molly or lithium based grease depending what you are greasing...
Good luck!
89Truk