sorry to just jump in here, but are any of yalls trucks doing this at 29-32mph as well? Reason I ask is my 03 did at both 29-32 and right near 67-71, dealer looked for two months and found nothing, I went off rd, bent the front shaft, took it off while waiting on replacement and no vibe at all, just my .02

 

Flamered, I have the 3.73's.

 

Well then I guess that makes sense then! Thanks for the reply bgott.

As for John Halter's suggestion - while I have not read the service manual yet for balancing the driveshaft, the thought of being under the truck while it is running at 70+ is a little unnerving. Maybe if only I had a proper garage facility...

PurNLoud - I do not have the vibration at lower speed, but pulling the front driveshaft is easy enough - I might try - or I might just wait and then complain again if/when I take my next trip down south!

 

I had a vibration at 70 until I added ceramic beads to the tires. It's gone now.

 

I would hope the dealer would let you use his hoist since it should be his find not yours . I went for months looking and guessing and the only way to find it for sure is to take it up to speed and go under neath the beast . It is not that dangerous on a good lift but nothing I would do on jack stands and a creeper . It sure is a lot safer than standing beside a truck on a dyno under load . If I was to guess It would be the rear drive shaft out of balance causing it . The service manual has you take to large hose clamps and move them around the shaft until balanced . The manual explains better then me just ask dealer to print off section for you .