My truck has a serious whine issue in 1st gear. As soon as it shifts the whine goes away. Its been doing it since i bought it (about 2 years ago) and i thought i would get used to it, but it is really starting to annoy me now and any passengers i have in the vehicle. With the windows up i cant even hear my cat-back system because the whine is soo loud. I've dropped the tranny pan and drained to TC last year and filled back up with Mercon V, which didn;t help at all. I thought maybe the diff, but that had a fluid change when i bought it and i would think if the diff was the problem, then it would whine in all gears. Anyone have any ideas?? Thanks

 

I also have a whine on my 98 F150 5.4. It's been around for a few years and I thought it was an accessory until I pulled the serp. belt and it still did it. I'd like to know what it is also, drives me crazy.

 

It's called gear noise. The 4R70W is famous for it.

The only way to make it go away is to change the gears in the trans. And then it's a crapshoot if you get a set the is better, the same, or worse.