Strange I'll Call it wheel hop

[Alan_nc]

94, 3.0, Auto
After the truck warms up and I have been driving for several miles I "sometimes" get an action that feels like I have a flat tire. On a definite rotation cycle I get a thump or bump like a tire was hitting a bad spot. Seems to go away if you continue to drive. It is sever enough to shake the truck.

Universal going bad?
Rear end problem?

Any suggestions would be appreciated.

 

[Uncle Gump]

Usually a u-joint doesn't care if it's "warmed up"... if it's bad it's a constant.

I think the first thing I would do is rotate the tires and see if it moves the issue. While the wheels are off take a hard look at the brakes and suspension system front and rear.

 

[Alan_nc]

It has always happened on a straight road, level not real bumpy after I have driven at least 5 miles. It feels like one of the wheels is hitting a rut on some kind of a rotation cycle. Lasts about a quarter of a mile and then the ride is completely smooth again.

 

[Dirtman]

Not to sound sarcastic but... Does this always happen on the same road? Meaning, you just keep driving over a crappy section of road every day and thinking its the truck?

Again not at all being, i swore my old rsmcharger kept warping rotors because it would vibrate coming to a stop every day going to and from work. Turns out they just installed grooves in the road before all the stop lights...

 

[sgtsandman]

Just spit balling but it could be a slipping belt in one of the tires. I would go with the rotating the tires suggestion and see if the issue moves as well.