Any tips on where to start looking for a popping noise intermittently when turning left? It is coming from front.

 

Is it a single pop or continuous?
Can you describe it any better?

 

After you do what Spike mentioned when was the last time you greased the front hub? I am willing to bet your CV joint in the axle is started to think it may explode soon.

If you turn harder it may get louder and then one time you will not be able to move, I had that happen to me on my D1.

 

does it only happen on pavement, or dirt and gravel too?

 

it is a single pop,no grinding or anything.I did find one of the steer box bolts loose(what a bitch to get to) and tightened it.

 

Crawl under the truck and start checking and tighten every bushing, especially your shocks.