I did my own LOF at 2500 and 5000. Turned 7500 and I am going to be straight out for the next 3 weeks so I went to dealer for a LOF and tire rotation. Went to Woburn GMC in Woburn MA where I purchased. total came to $90. As I was walking to truck with service advisor he was telling me what was done and said"....added 12 quarts..." I said, hey the Duramax only takes 10 quarts. He replied "well I told you when you called we dont work on many diesels" WTF!!!!Anyway, does anyone know of a good diesel mechanic/shop in Northeastern Mass/southern New Hampshire? Thanks.