Can't find vibration source......
 

My rig vibrates since I bought it in March. Mostly highway speeds above 55 it starts. Not a heavy vibration, more of a light one....can see the rear view mirror shake and feels more like I am riding on big knobby tires.

I removed the rims/tires and rebalanced and rotated them...they are true and balanced well. Driveshafts feel tight and no play in the driveline or u-joints I can feel, rear end feels ok also. Should I remove one driveshaft at a time to isolate things?....any ideas? Driving me nuts.

try coasting and neutral and see if it goes away that way you can eliminate most of the power train..

u joint are pretty common in the 3/4 ton. there has to be no stress on the driveline when checking u joints. you will be safe removing the front driveshaft from the truck to isolate the problem.

Don't know if you have the problem figured out yet. But if your truck has a mid-ship bearing in it you might want to check that also I had that same issue with mine.

Thanks guys, still haven't found it...no mid-ship bearings and u-joints feel tight. Vibrates only above 60MPH and doesn't go away unless I drive slower then that speed. Very annoying, still feels like I am driving on big knobby tires. Any other ideas?

Is it possible to find a cap to place in the rear of the transfer case so I can drive without the rear driveshaft for a bit just to isolate it?

If you're thinking of pulling the rear drive-shaft, I'd just replace the u-joints and be done with it. These trucks eat ball joints and u-joints like crazy. I had a rear u-joint go around 30k and ball joints before 60k.

i had vibrations like that happen to me before and it turned out to be that i did not have tapered lug nuts that perfectly centered the wheels. other than that did you try and rotate your tires? maybe you have a slight seperation somewhere?

Not replacing u-joints needlessly, they aren't loose...I wish it was that easy...and the tires, rims, lugs and balancing are all ok....

Normally u-joint vibes are at lower speeds (5 - 15 MPH) and upon acceleration and deceleration.

If it's over 45 MPH's, more than likely it's the tires.

I know you said you had them balanced, but did they get checked for out of round?

They may balance perfect but be as round as a Rubik's Cube.

that was my point exactly coal. seperations are hard to identify sometimes but they will for damn sure shake your truck. i would rotate the tires to see if you feel the shaking move from the front to the rear and isolate the problem tire.