We have a 08 9770 with 500 hr blowing coolant out . 2 sleeves not shimmed to proper spec. Deere wants to put more shims in all sleeves to give more bite on gasket . Engine was also starting to use oil ,possibly related to head gasket but not sure.Has anyone else had this problem, how was it resolved ? We and dealership would have preferred a new block .How long of extended warranty should we be looking for ?