Hi all...first post here! <img src="images/icons/smile.gif" border="0">

I have a 2000 Silverado Z71 reg. cab, longbed 4x4.

I noticed on the highway tonight a droning/vibration coming from the back anytime I would hit about 88mph and up.

Any ideas?

 

Tire possibly? I would say driveshaft, but I think you'd notice a vibration from that long before 88mph.

 

Stock wheels & tires?
Any mods?

 

Everything is stock and low mileage (6000)

Firestone Wilderness A/T(?) 265/75/16

I was thinking of going out tonight and doing the same thing on the highway except keep it in 3rd instead of overdrive. I assume if the vibration stops then it can be related to the driveshaft.

 

Tried it in 3....

Didn't seem as bad as when in overdrive

 

Firestone's, you needn't say any more! <img src="images/icons/grin.gif" border="0">

As I said, if it were the driveshaft you would hear it sooner (like around 40mph), same things with the rear end.

As to the tailgate, did you try driving with it down to see if it still does it?

 

Lane,

That was certainly one thing on my list:

-tire
-wheel (balance)
-driveshaft
-resistance from closed tailgate

The droning is pretty loud at that speed, and prior to those speeds not a peep or vibration to be felt.

 

I didn't try that....I figured that would be quite a stretch and something that GM would've accounted for in the design of the truck (I would hope).

I might though just to eliminate the possibility.

 

The thought hit me last night, and I have a sneaking suspicion....could it be the bug deflector on the hood vibrating?

When I heard it the other night it almost sounds/feels as if the front of the truck is where the vibration originates.

I'm gonna pull that thing off and see if it changes anything.

 

Open the darned tail gate before you go through the effort of removing the bug guard - start simple then expend the effort ....