in reverse under stress, getting a squeal

[GaryS]

I have a 1428V which is in good shape. I do get a squeal when going in reverse under stress. I have lots of steep hills that I rough cut and I do cut forward & backward to eliminate the need to turn around at the top of the hill. When hogging in reverse, I get the squeal and it sounds like to comes from under the hood. Is this normal or is there an issue that should be addressed?