my car, 1998 ford explorer 82k miles , recently very vibrating when I
run on a slightly uneven road.  It becomes shaking on uneven freeway
at speed 60 miles.  I have did agliment, tire rotation and tire
balance but the problem still stays the same.  I was wondering if
something is wrong with the suspension system.  If so, where can I
bring it in to fix the problem?  Is it good idea to take it to the
ford service (dealer)?

Thanks in advance.