OK, I still have vibrations at 50 mph plus or so. I have had the tires balanced, and then re-balanced on another machine. Anyone have any idea's? I can feel it in the whole truck.

????

 

it could be a universal going out. the easest way to check is to jack up the rear end and see if their is play in the u-joints when you rotate the shaft back and forth by hand if their is a slightest bit of play they are bad and need replacing

 

Check the tire tread for signs of separation. If there isn't any vibration at lower speeds it could be that the tread is (for want of a better discription) bulging at the higher speeds causing the tire to be out of round. If it seems to get a little squirrely at the higher speeds that could be an indication that the tire is separating.

I'm gonna go out on a limb here and assume that you have checked the drive shaft for bent or dents or missing weights. Also assume you checked the U-joints and flange at the differential.

You didn't say what truck you have so the only other weird one that I've heard of is if it has drum brakes then check the drums for missing weights.

Well that is about all the BS I can sling- hope you find it!

 

I had really bad shaking before I replaced my rotors. It may not be this for you, seeing as it only happens above 50mph, but it might be worth checking out if they're warped...

 

Does it still have the perelli scorpions? Those could be a big problem too. Those were known for vibrations. I added a fabtech dual steering stabilizer to my truck 3 days ago and helped out alot. Granted I have bigger tires but that option could help you out also

 

e-brake drag... Just one more damn thing to check...

 

If you search there will be a lot of posts on this issue. I for one have had bed shaking and steering wheel nibble at 50 to 60 mph since I bought the truck new. Took it to the dealer multiple times with very little success on getting the issue resolved. The only cure I have found is to get rid of the OEM Ameritrac tires and have the tires roadforce balanced but that is only a temporary fix as it always comes back a few months later. With the different tires the shake is not as bad as it was the the OEM tires. After 5 years I have just learned to deal with it and have given up trying to obtain a smooth ride.

Not sure if you bought the truck new so the truck might have had the vibration like mine since it was new. However if it just started it could be caused by some the areas others have mentioned.

Good luck