99 Silverado weird noise during acceleration

Have 90k miles 5.3 4x4.
For about 1 second, while accelerating, I hear the weirdest noise. It's like a droning of sorts. Other than the sound, everything seems fine.
What could this be?
thanks.
chris
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
c wrote:

If it's the new body style..... & it is with the 5.3 motor...
It could be the drive shaft splined slip yoke sticking...
The yoke must extend & compress on axle wind up & over bumps..
The GM 'slippery' grease put on the splines ($35) or buy
the ($150) nickel plated slip yoke that doesn't stick.....
Be ware: There are a ton of Chev Slip yoke part Nos..
For ride quality improvement... Every Spring is a slip yoke
cleaning & greasing..... on my 00 5.3 Z-71 Ext. Cab LT.....
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.