Chasing down vibration

Lots to read in the search block, top right corner.

 

Have you done HD's running it on stands and or the red Mustang guy's? knock the axles out, lock the PD and run it to see if it is a driveline or other problem. I would start there after everything you have already done. Just my opinion, good luck and let us know what you find.

 

These are really hard to explain as to what people perceive as a vibration and may be different person to person. There are vibrations, shimmies and shakes. They are all different and all mean different things. Certain speeds or certain frequencies can help to pinpoint what could be causing it. Tires spin about 4 times slower than drivelines. So usually a tire will cause more of shimmy or shake that you almost the count the thumps as they happen. Tires usually cause the whole truck to shake, the hood to shake. Drive tires will cause it to be felt in the seat, steer tires cause the steering wheel to shimmy back and forth. Tires usually only show up at a certain speed range and may completely disappear above or below that speed sweet spot. Drive lines usually cause a different feeling. Since they spin about 4 times faster and have less mass, they normally cause a buzz or hum sensation that is way too high in frequency to be able to count. Driveline vibrations usually change in intensity with changes in driveshaft load, eg being on the throttle or not, or in gear or coasting in neutral.

One thing you did not mention is the type of suspension you have. If you have an air ride, first check is always the proper ride height.

 

Some experienced people can drive a truck and point you in the correct area many times. Other times everyone is driven crazy and thousands of dollars are dumped for nothing. You might post everything you have done and checked. How did you check drive line angles and driveshaft alignment phasing? I do not mean to be a smart butt. Just hate to see anyone spend a lot of money because they over looked a driveshaft 1/4 turn out, easy to overlook, or a rim that was packed full of dirt and half of it fell out. Use a heat gun and check the u=joints when it comes in off the road.