I had mine up to 50mph today very briefly as I need an alignment really bad and didn't want to push it. I got a vibe/shake starting at about 50mph. I figure first possibility is improperly imbalaced tires or maybe just need the alignment. Getting one tomorrow so we'll see what happens. Otherwise it seems fine.
I has my alignment done and do not experience any vibes at all....none that I can feel. Although I find my truck now pulls to the right. On perfectly flat roads it is ok. But on bumps or uneven surfaces it pulls right...occasioannly left. I may bring it back to get them to check again.
Use power tools if you have them for the new front bolts/nuts. The new nuts are crimped so they won't ever loosen, and it's a long hard process cranking them all that way down by hand. Trust me, I know!
finally got around to putting on the diff drop today since the vibe started vibrating at a lower speed 20mph. Got my wheels balanced, didnt work. Did the cb drop, helped alot but was still there. Finally was fed up with it and said to myself if this diff drop kit does not work im gonna have to sale the truck. Guess what no more vibes smooth as stock. Also help the shutter a lot, i dont know how but it worked im so relieved, for now.