So first of all, a little introduction is in order...
Truck is a 2001 dodge ram 1500 sport, 5.9l 4sp auto, club cab, 4 door, 160,000 miles.
This truck is brand new to me, and i got it for a reasonable price. However it does have a few issues I'm aware of, but on the main issues that concerns me, is when I'm driving at highway speeds (60-75MPH etc) and coast, the truck vibrates pretty loudly, and makes weird noises, but its better when I'm on the gas, but coasting is worse. The noise doesn't seem to stop until the trans downshifts into 3rd from deceleration. Unrelated or maybe even related the truck doesn't vibrate during city driving, but occasionally vibrates (like u-joints or out of balanced tires) on the highway.
It makes me uneasy driving on the highway because of this. the vibration is okay, not too bad, but the noise that the engine seems to make at about 2,300 rpm until it downshifts, scares me.
Does anyone have any idea what could be causing this? the engine seems to be strong, idles pretty good, i can't think of what it might be and hope maybe someone on here as an idea.
Anyways, sorry for the long write up, and thanks in advance.
- Erik

 

Welcome to the forum. You are on the right track. Anything that rotates at speed is suspect. Start wit inspecting u-joints, brakes, axles, tires, wheels, etc. Kinda hard for us to diagnose. Do a little troubleshooting and eliminate things one at a time.

 

that's definitely an issue in your suspension. Check all ball joints, u joints, and any loose suspension parts. Also i would check to see if your tires are wearing uneven. A good sign of failing ball joints and u joints is that you will notice a camber on your tires which will lead to bad wear. If everything looks ok, you might wanna try aligning it.