Gentlemen,
I am new to this forum and I have been searching for an answer to my truck shaking for a few weeks now. Since it began shaking I have had the tires balanced, replaced the u-joints (I found a broken one). Replaced the front propshaft completely. Finally Yesterday I replaced the transfer case output bearing. Truck still shakes above 70mph. When I pull the front shaft out the shaking goes away. I can feel the shaking with the front shaft in around 40mph but it smooths out then at 70-80 is shake a lot. What are the chances of it being a bad balance on the new shaft? I went cheap and bought a masterpro from Orielly auto parts. Also to note when I changed the transfer case fluid there was what I thought an abnormal amount of metal shavings on the plug. Does anyone know of internal issues from the transfer case I should start looking at?

 

I'm not sure this is helpful at all but I had the same issue shortly after I bought my truck (I mean way back in 2000!). I replaced the brand new tires, had the driveshaft checked (I lived a long way from the dealership). Ultimately I took it back and they decided it was the transfer case and replaced it. I have no idea what the problem was, but the shaking went away.

 

Does it need new tires? Some times with uneven wear, bad struts, or both cars and trucks can shake when your at those higher miles.

 

Shane, defenetly your problem is the front dshaft, could also be a bad flange, also check
your 8 bolts and nuts.to be fully tightened. also bring the frdriveshaft to be balanced to a machineshop
best wishes.
jaimelu