Newer F150 drive shaft

[Injpumped]

Heck, I'd pull the driveshaft out, check it over, and then take it for a quick diagnostic drive on the front axle and see what it does. I'm guessing the joints are getting stiff and causing the whole shaft to whip, or "jump rope" causing all sorts of issues. Of course, a seasoned mechanic notices the problems early on to prevent further failure. 

I'd imagine it has a companion flange at transfer case end, don't think it'd have a slip yoke style with a carrier bearing?

Edited March 17 by Injpumped
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[acem]

Do you feel the vibration in the seat or steering wheel?

How are the shocks?

Many other good questions already asked.

[stronger800]

Only about 10 bolts to remove the shaft and feel it, and drive truck without it I suppose.  
actually I can’t picture what the upper end of the shaft looks like…does it pull out of the transmission?

[JaredT]

If it was a rear tire you likely wouldn't feel it in the steering wheel. But if it's a front tire you should. The tire rotation you have planned should rule out tires.

[Cattech]

Well, after alignment & tire balancing / rotation, then a whole bunch of messing around with the aftermarket shafts not being the correct length, or having the hanger bearing in the wrong spot, dealing with technical hotlines, returning supposedly mis-packaged parts & ordering more, I finally broke down and bought the factory Ford part.

Have to give a shout out to Steve at Fort Wayne Clutch and Driveline in Indiana, he was a great help even after we decided I wasn't going to be buying from them. Apparently, they can build just about any driveshaft you could ever need from a technical drawing. They also build quite a few automotive driveshafts by part number. 

Got the latest PN Ford shaft in and the vibration is gone, runs smooth right up to the speed limiter. And now that I have the old shaft on the ground where I can play with it, I won't say this is certain - but I'm thinking the vibration was coming from the CV boot on the pinion end. it is a heavy/thick rubber and it scrunched down around the joint to a point that it limits the flex of the CV joint.