as all have stated truck will need to drive well before both will work together.
our equalizer dealer set our hitch up with trailer. but will stress it took me 3 other attempts before i got it to the sweet spot. don't be afraid to tweak hitch. once you get it dialed in you will be amazed at the difference.
still sounds like ball joints tie rod ends or shocks on your truck. if you have had it to the shop and they say all is well, i am not sure how to tell you proceed.
this is tough because you don't want to start throwing parts on till you solve the problem.
is it possible for you and hubby to jack the front end off the ground and block up.
then get a 3 or so foot bar and start prying and working the suspension parts in out and up and down? with one in the cab. work the steering wheel back and forth while the other looks for play, all the way from the wheel and bearing to the
steering box.
2003 truck is old enough for any of the front end parts to need service.
also equalizer has a great web sight
http://www.equalizerhitch.com/Equal-i-zer%20Support/index.php
post isn't much help to you but stress. hang in there you have a good combo that can work.
