I have a 4310 with a fel and 3-point finish mower.When i raise or lower the loader or mower at 2000 rpm or higher,the hydraulics make a loud and rather high pitched noise ,that comes from under the seat.The dealer checked it and said that it is normal.They also said they tried it on other tractors at their dealership and they did it also.Has anyone else experienced this ?Other than this i love everything about the tractor.