The bearings inside the boot could be bad. Just because the boots not broken doesnt mean something isnt broken. You sure your hub is clicking and not the tranny side. Do you launch the car ? Or drive the shit out of it, Do burn outs etc etc, You could have other issues. As for the smell... You could just have an exhaust leak. How about you you give us more details like Car, Engine, Mods... Etc etc. This will better help us determine the problem.