I've been noticing that my transmission shifts much more firm/rougher than my brother'* 2000 SLE. His has 62,000 miles, my Aurora has 39,000 miles. I thought it should be the other way around. anyway, I checked my fluid and it is quite a bit below the hatched area on the dipstick. It looks to be about 3/4 of a liter low. Will a fluid level just a little bit below the hatched area cause the rough shifting? I didn't think that little bit of fluid would make that much of a difference really. What kind of fluid should I add to it? Will anything Dexron III work? It'* a 4t65E BTW that'* on the V6 Aurora.