jeep grand cherokee 20k mile service question, please help

A dealer trying to do unneeded work?! who woulda thunk? Please get an owner's manual and keep track of the recommended maintenance- do NOT trust the dealer to tell you what your car needs-

Thanks for the replies people, I appreciate it. We were going to take her jeep into the valencia, ca dealer. When I looked up the service maintenance recommendations, and thanks to you're answers on here and asked why they wanted to charge her for an alignment and a 4x4 service when it wasn't in the service manuals (they wanted to change the fluids in both axles and the transfer case) and I told them the fluids should only be inspected at this point the service rep steve actually got rude with me , interrupted me and tried to talk over me and when I told him he was wrong he actually hung up on me haha. At this point we are getting her tires rotated and an oil change done at a local bridgestone auto-repair shop and I'm changing the air cleaner for her. Thanks again for everyone's replies and help!