When I was a kid, I watched my grandfather balance a driveshaft on the family stationwagon by putting the rear up on jack stands, then putting it in high gear and running it up to where the vibes were most prevalant. Then he got under the car (while it was still running in gear) and held piece of chalk up to various points on the drive shaft while it was spinning. Once he was done, he shut it off and positioned hose clamps so that the gear mechanism was in the center of the gap in any of the marks that didn't go all the way around the driveshaft. It only took him one try to fix that car. Of course he could fix anything with spit and bailing wire.

 

Haven't heard much lately about it but it was a popular buzz back when I bought my 04. The power steering hoses would pulsate. There was a weight the dealer would put on them and tie them together. I just ziptied them together in a couple of places and has held smooth for 280,000. Might be worth a try?

 

I had this issue on my 04.5 after I wore out a u-joint at about 60,000 rear shaft rear joint ,had some hacker joint repace it seens I was 200 mi from home it lasted about 350 miles and when I removed the shaft they had bent the ears also they had not marked the shaft or indexed the slider ,replaced the shaft no luck vibes under load 55-65 so I replaced the tailshaft housing no luck so I turned the shft at the pinion ,no luck so I turned the shaft at the slider 1 tooth at a time until I finally got it real close the indexing is what it needed for me

 

how did you tell it was right? did you move it one tooth and drive it,repeat , repeat? i am chasing a similiar vibe i put new joints with not alot of diffrence pulled the front shaft same deal, i know the shaft has been out before i pulled it as the joints had been replaced by the PO my vibe isnt real bad but is a 55-75 mph constant...