Whenever I stop or start to go, I often hear a clunking type noise in the rear of the vehicle. When I brought it to GM I was told something was leaking and a new seal was put in. Probably the axel in the back. It is still making this noise months later. Any ideas?

 

Go back to the dealer then. THey should warrenty work for 12,000 miles or 1 year.

 

It could be coming from the differential. I had a very similar problem last year. I put new Diff. fluid in along with the additive and the sound went away.