Left rear end chatter

Hi all...fairly new to the forum. I have a 94 rodeo with 96k and experiencing some left rear end chatter noise. This noise sometimes occurs when accelarating from a stop position and dissapears within a few seconds....the noise especially occurs when accelerating around a corner. The noise is rarely heard with normal turning or accelerating at highway speeds. Mechanic could not find anything wrong.
Could this be the slip differential and if so why does it not happen when cornering at normal speeds?
Thanks for any info

Saw your other post about the 4x4 not engaging. On the 94 models, they have auto locking front hubs. These are mechanical devices, NOT acutated my any electrical, vaccum, or other means. If they are not engaging, they are probably dirty inside ( makes them stick ). They are not too hard to service yourself. Just pull the front wheel off, and the locking hub cover. It's been a long time since I had one of these apart so I don't remember everything. But, there are a few parts in there. Pull them out, careful about how they go back together, clean them real good and put it back together with lots of axle grease. Not TOO much that you hinder the movement of the parts inside, but enough to lubricate them fully. This is a spring-loaded mechanism. If there is rust or corosion in there, that will stop them from engaging. Or, if the grease is old and thick that can do it too. Remember, the front differential is 'open' so BOTH hubs must engage for the 4wd to work. If only one of them is not working, no 4wd.

To engage the 4x4, you put it lever in 4wd and have to drive forward a few feet before they engage. You don't want to do this when your wheels are spinning. You do it slowly or you can damage the lockiing hubs. Conversely, to disengage, put it in 2wd and back up a few feet.

I have a noise when im stopped or right when I take of .I looked under there and it was an exaust rattle.Check the area right before the muffler I had a heat shield loose!