Truck Tried to Shake Itself to Death

[MStearns]

Looking for some ideas on what may have caused this.... Running along on the highway yesterday between 55 & 60 mph when I hit a pot hole/gap in the road and my truck suddenly tried to shake itself (and me to death). It was as if I was suddenly on a horrible washboard road. The truck was controllable but the shaking/bucking continued as I slowed and pulled off onto the shoulder. I jumped out expecting to find the right front tire had thrown the tread and suddenly become square or at least was flat but nothing appeared to be wrong. I looked everything over. The wheel weights appeared to be all in place. No broken springs or linkages. The shocks appeared intact. There was no obvious culprit.

I jumped back in the truck and took off again. Slow at first, then back up to speed with no problems at all. The truck doesn't appear to ride any different than in did before. When I got to a friends house, I did let some air out of the tires (All four corners were around 70psi as I had been towing last month and just never took the time to reset the tires). I've hit several bumps and potholes since (I've put a little over 200 miles on the truck since this happened) with no repeat.

I don't know if this was some freak thing, some weird harmonic oscilation that the bump/road set up, or if something is broke. Regardless I don't wish to repeat a ride like that. Thankfully it was "controllable" and there wasn't anyone else on the road with me! But I may not be so lucky if there is a next time. So any suggestions or recommendations would be greatly appreciated!