Checked the front drive shaft it appears to be factory with snap rings and no visible grease buttons.

 

It looks like this one

 

Try grabbing it to check for play in the u-joints. I suspect you'll hear some bad noises - should be nice and tight.

 

mine was tight with no play at all but the unjoint cap was cracked at the base. I had a bad vibration. Replaced with a lucky 8 one and everything was fine after that.
i didn’t see the bad cap until old shaft removed and then I could feel it and see the bad cap

 

Agreed, the feel inspection is only valid with it out of the truck - 8 bolts.