84 720 2wd - super noisey and vibrates over 40 mph.

[mikepolk]

This just started about a week ago. Over 40 mph it get really noisey and vibrates really bad. If I let off of the accelerator, the vibration and noise stops. What is this?

[drumaniac3000]

u-joints possibly?

[lambohaha]

Belts separating on your tires? Wheel weight fall off?

[MetalFab]

U-joints can lead to some really interesting sounds, and is the first thing to look for if you have vibration. Get under the truck and try to rotate the driveline back and forth. it's easier if the rear tires are off the ground but if there is any play at all then you've found the culprit. Also the majority of drivelines have some kind of weight welded onto them, it's rare that they come off but it would be good to inspect and see that there is a weight on it, and that there aren't any weld spots with something missing.

[breadbox]

Id say driveshaft.

[captainzeros]

on my 2wd there is a rubber bushing around the driveshaft. It rotted out and then the driveshaft started shaking around which made a real scary noise at speed. Crawl under you truck and see if you can move the driveshaft left/right/up/down to check on that.

[lambohaha]

What about the carrier bearing? Maybe its going south

[lambohaha]

Well? Any new developments?

[86 720]

wheel bearing, or steering pump?