[GreenmtnTitan]

Just to refresh from my earlier post: My truck had the same wobble with a COMPLETELY DIFFERENT set of tires AND wheels. Even the tire brand was different (Goodyears instead of BFG's).

On my truck at least the tires/wheels do NOT seem to be the problem, unless those other tires and wheels were bad in the same way as mine...

If the shock theory is true, might the condition change as the shocks wear/break-in?

As far as ruling out the driveshaft as a culprit, a driveshaft vibration that is "harmonic" in nature and was VERY slight at lower speeds COULD increase in magnitude at other harmonic intervals as speed is increased. Theoretically if you could get the truck to 140 mph the vibration might reoccur and be severe enough to cause a failure... or not, that's the nature of harmonic vibrations. If you've ever been near any BIG equipment (specifically 600+ Megawatt steam driven turbine generator sets) on their way to high RPM, you should recognize that there are certain "critical speeds" where the machine is NOT HAPPY and neither is anyone standing nearby. Such rotating masses usually have more than one critical speed zone. That's my though on the driveshaft, plus all those little weights tacked on there just scream "sh-tty workmanship"

Did anyone else look at their driveshafts to see how many little weights are welded on?

CD