Transmission vibrate/&hum betw/ 30 & 40mph?
Hi, I have a 96 pontiac sunfire(mileage 177233). The auto transmission was replaced at 95600 miles. It has been running fine and still is only I don't know if I have a problem. When driving if i maintain a speed between 30 and 40 mph, the transmission vibrates and hums, almost like it is between shifting gears, I have the slow or increase speed to make it stop. When I increase past 40, you can feel it shift up and everything is fine. I'm just posting this becuase it is quite annoying because I live in the city and have to drive in the 30-40 mph range alot. Does anyone know what I'm talking about and if so is this a problem? If so what and how to fix. Or could this just be one of those engine qwirks?