rattle??

First off this is my first post so be gentle guys. I bought a 98 xj maybe four months ago with 73000 miles all power including sunroof. I paid 8 grand for it from a dealer with no warranty,did I do ok? Second I cannot get the brakes to stop squealing its just the front passenger side. Ok third question of the day I just noticed a light rattling sound coming from upfront but can't pinpoint it by myself so figured you guys might narrow the search. Is it hard to change gears in a d30 and 35, and just to make sure will 4.10's out of a 93 wrangler work in mine? Any and all help greatly appreciated.
mikie

Concerning the brake squeal; you might check to see if the anti-rattle clips are in place. These could potentially contribute to both the squeal and light grating or rattling sound. If the rattle clips are fine, then consider something like Permatex anti-squeal. This is an adhesive compound that prevents the brake pad from oscillating when you apply the brakes; the stuff will disintegrate when brake cleaner is applied so future brake work is not problematic.

the rattling could possibly be your cat, its happened on 3 of 3 of my jeeps