I've got a 98 f150 4x4 lariat 5.4L and I'm hearing whining noise that sounds like its coming from the trans. The whining happens in park and also while driving. The whine persists and all the way thru the gears until u hit 45 and the truck shifts into its highway gear. Once it does shift the noise completely stops. It's really bad right at 40mph and the noise seems to be consistent with the rpm of the motor. Any guesses what it might be?

 

When was the last time you had the trans fluid checked/changed?

http://transmissioncenter.net/Transm...Noise_Help.htm

 

Way back, my 70 Mustang with C4 automatic had a whine when I first put it in reverse or drive. After stepping on the gas and getting moving the whine went away. I was positive it was the transmission. I was on a trip when I saw I was going to exceed my 50k mile drive train warranty so I pulled into a Ford Dealership in Ft. Smith Arkansas mostly to get the issue documented for warranty reasons before the warranty expired. Several people looked at it and listened and they all agreed that it was a transmission issue. Then someone said, "Let's get ol Joe to look at it". He was evidently a long time mechanic who was in an office drinking coffee with his feet on someones desk. Joe came out, listened, got inside and shifted it while holding the brake, and then got the longest screwdriver I've ever seen and placed one end on different parts under the hood and the other end to his ear. He said, "take off the fan belt and listen" and picked up his coffee cup and went back into the office. A mechanic took off the fan belt and the noise stopped. The alternator was making the noise!! So, it's hard to tell sometimes exactly what the noise is or where it's coming from.

 

^ what a badass! I'd love to see a mechanic that good at work