Every night when I start my truck and it's cold outside, my truck screams like crazy. I usually let it run for 10 minutes or so. I have a 98 4.6 with a 4R70W tranny. It doesn't like to shift into 3rd gear unless I'm going 30 mph or more. I have a screen front on thinking maybe it was too cold but it still does it. The squeal gets louder with higher rpms. Any help would be appreciated. Thanks.

 

If you have not changed your belt in a while I would try that first. It sounds like that may be your problem.