I have this squeal sound coming from ( I think transmission ). It sound like a low pitch squeal like from a loose belt ) If I put the car in park rev the engine no squeal, normal drive no squeal just during passing gear on express way or fast acceleration. My Subie has 83,000 miles on it but I had a rebuilt trans put in around 32,000. ( long story ). I checked the trans level it's ok so is it a trans issue or engine issue? I have not yet change the trans fluid since rebuilt. I was going to do a flush and fill but have heard that it's not wise to flush just change. Any one have any feed back or ideas.