I know this isn"t a tractor but maybe someone has run into this......2008 PT Cruiser 42000 miles. I bought it with 11000 on it. There is a growling noise in the front end that I attributed to tire noise but new tires hasn"t changed it. It is gradually getting worse. Noise doesn"t change under load, it is the same in gear or out of gear.I"ve even been under it with the thing showing 60 on the speedo and can"t find it with a stethascope. It seems louder in the car that under it. I"m thinking it"s in the diff and was prepared to drop the pan and check the fluid but it looks and smells OK. The book say"s you never have to change the tranny oil so I stopped there. Any ideas? EGBinOR