Ok, so I did searching through the threads and found only a few instances where there is vibration at 65mph and above. I found four threads, I think only one actually had an answer which was wheel balancing, and the rest either were unrelated vibrations, or had no answer or input. The problem is that I just had the clutch replaced, and I don't think it is in the wheels. The vibration is present when traveling at 65mph and above and is still present when I push the clutch in or put the thing in neutral. Its a vibration that is felt throughout the cab, in the stick, and a little in the wheel, although I haven't had the time to check if it is privy to one area. I'm losing my mind, and ready to shoot the mechanic who is acting like it has nothing to do with tearing the tranny out. Any thoughts would be appreciated.

 

Did it start after the clutch job? If so, have a look at the rear driveshaft.

 

check the the driveshaft for cracks or bends.
my brother in law had a driveline vibration only when he put it to the floor. we thought it was something with the engine but while doing his exhaust system i found a fairly large crack in the shaft. no idea from what. i told him about it and a few weeks after,the driveshaft broke in half. he replaced the driveshaft and the vibrations stopped. just tossin that out there.

 

Try balancing the driveshaft. I had the same problems and it works great. I couldn't go more than 70 before now I cruise at 80

 

I had the same problem. Ended up being a few things:

1. I had a suspension lift (blocks) in the rear. Lift block on stock block and 2 U bolts holding them together. The U bolts were coming loose and the rear axle was actually moving because of it.
2. Probably BECAUSE of #1: U joint on the driveshaft was weak.

My driveshaft fell off because of it.

Check U bolts, check your U joints.

 

This may be a long shot, but unbolt the drive shaft and rotate it 180 degrees and re-install. I've had this happen one other time and it doesn't make any sense, but worked.

 

Wonder if he got it fixed......

 

Lol, hey fella's. Sorry I haven't updated this. Had to drive it back to PA to drop my mom off and didn't have access to a computer, well I did, but my girl is a little preoccupying... Anyhoo, so for some reason, whilst driving, I'm troubleshooting in my head, trying to figure out what this could be, and I had the dumbest idea. It was coming from the middle of the floor, right above the tranny. Now it didn't matter if I had it in neutral or had the clutch pressed. So I look down, at the 4x4 stick, and grab it... it was almost in 4high... you have to be F-ing kidding me!!!!!! Pushed it back to 2high and the vibration stopped. I almost punched my mom I was so pissed at myself. I called the mechanic and let him know we are both idiots. Soooooo, if you do a clutch job, and have a vibration, check the stick first to make sure that after you crammed the tranny and transfer case back in that your 4x4 stick is properly in it's place. It wasn't in 4x4 obviously, I had no light on, and the highway drive home would have fried it. It must have been just touching inside the transfer case and once the tranny reached a certain frequency it caused the vibration.

 

Darn. That is a little scary. Wonder if it caused any wear in the transfer case.

 

I am glad you didn't punch your mom.