2002 MDX Issue While Stopping in Gear

I have a 2002 Acura MDX with 196,000 miles that has a strange issue. Sometimes when I am stopped (with my foot on the brake) while in gear it will try to lurch forward a little bit and has stalled on me twice when doing this, both times while waiting on a long red light. This only happens when it has been running for a while and it does not happen when running cold or in park/neutral. I think it could be a transmission/transfer case issue. Sometimes I notice a light grinding sound coming from around the transfer case when I put it in gear. The ATF looks full and clean every time I check. All of the gears work fine, there is no slippage whatsoever when shifting. There is no check engine light coming on either. Help me figure this out before I take it to a shop, I am stumped.