This is one of those hard to describe sounds, but I'll give it a go.

When I first accelerate from a standing stop I hear/feel a "clunk" - like the motor is revving up and then the transmission or drive shaft or differential is engaged. I have a '96 EB with the 5.8 engine [:->], limited slip differential and strickly stock except a K&N filter. I run Mobil1 engine oil and recently had the differentials drained and replaced with Mobil1 differential grease. My wife's Nissian Pathfinder SE, 4wd also seems to have this sound.

Appreciate any help/advice given.

Thanks.

 

This sounds like a problem that I was having also...

I found the answer within the message boards about a year ago, it is your drive shaft. It is a two-piece shaft and the splines within need to be greased.