Re: '99 F250 Super Duty rythmic wheel thump
Cupping can be caused by many things, everything from an unbalanced tire to worn front end components such as a tie rod.
No need to pull it to check for bad bearing. I use the 'idiot' method: lift the wheel in question off the ground a few inches. Then, place one hand under and the other on top of the tire. If you can shake the tire towards you, then the bearing is pooched. A little bit of play might be enough to make the sound you mentioned. HD trucks can be harder to diagnose as the components are made stronger - and heavier.
If you can't see a difference by the 'idiot' method, then try a tire rotation to see if that makes a difference. Badly worn tires can cause some havoc. I would be cautious as you don't want to leave the rotated tire on that wheel too long, as it too will cup. If you are running original shocks on your '99 - replace them irregardless if they seem 'OK'. HD trucks are a lot harder to notice bad shocks, unless they're broken, bent, or leaking fluid (no fluid in gas shocks of course, hydraulic only).
'11 Ram Quad Cab 4x4 SXT 5.7L HEMI (stock); 48,500m
'06 Pontiac G6 GT 3.5L 220hp; 64,000m
'12 Chrysler 200 Limited 3.6L 283hp; 28,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!