hi guys have a john deere 6930 50k 2012 model autoquad,which came with 540/65/28 and 650/65/38 goodyear tyres,tyres replaced at 5600 hours and downsized a little to 480/70/28 and 580/70/38 klebers.problem is at 50k im getting an awful road noise in the form of a droneing noise.(never had noise in the goodyears the whole time).what are peoples thoughts on this problem,any help to resolve this would be greatly appreciated.I was thinking of changing the tyres again to michelins in the 480 and 580 sizes but afraid to spend the money and be no better.