I haven't gotten to doing it yet. But I did drop my truck off and they looked at the brakes and wheel bearings and said they were fine but thy couldn't duplicate the noise... When I got down the road it started doing it again lol.

 

2wd or 4x4? If 4x4, I've noticed the cv boots on the front whine when hot, dry and dirty. I coat the boot in silicone spray and get another year or two noise free. Plus it's just good to condition rubber pieces. U joint to me you'd feel a constant vibration. I might have missed it but is it only with brakes applied?

 

4x4 its coming from the rear somewhere. It only does it when accelerating from a low speed or dead stop. It is a rotating noise it's really bad in the morning when I take off it does it all the way down the road

 

Possibly a pinion bearing.

 

It sounds a lot like thiS but only at low speeds when I hit the gas and then it stops when I get past about 20. And does it once in a while not every single time I take off. It can't be brakes because when I let off the gas it stops durin the low speed. Does a driveshaft slightly slide out when accelerating?
http://m.youtube.com/watch?v=E7Svszf...?v=E7SvszfugnE
It's def not this fast sounding since this vehicle is doing like around 50 I guess. I heard pinion bearing noises and they sound nothing like it

 

Is here slip yokes on my truck? Maybe just something I can grease too. I know when I kick it on the highway I get a bad clunk and jerk when it accelerates. But I've tried moving the shaft and it's pretty tight

 

Noone

 

Bump.. It wasn't my u joint. Anyone?!?

 

Sounds like a wheel bearing, - if it's similar to that video. It could just be the rear gear fluid as well, but they usually vibrate around 50-55 mph when the fluid breaks down. The fluid @ max is only good for 100,000 miles. After that, if it's not changed, - not so funny things may begin to happen.

You can pull the rear drive shaft and just run without it to narrow it down. Keep in mind, - IF it doesn't hum like that without the shaft, - it doesn't mean that the problem is with the shaft.

Sounds funny I know, but IF you get the noise without the rear shaft on the truck, I'd service the wheel bearings and fluid at the same time.

Because! If you just service the fluid and it's a wheel bearing, - you'll be servicing the fluid twice to fix the problem. That stuff isn't cheap.

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You could also jack up the rear and check rear wheel play. Also spin the wheel and listen for anything peculiar or revealing rather.

Another thing to keep in mind. These rear ends hum to begin with, - some worse than others. Ford does have a kit to fix that, - BUT $$$. Bad broken down fluid and a wheel bearing going south can make it much more pronounced. Since it's Off an On again, I'd go thru procedures above for the best chance at pinpointing the issue and fixing it.

 

I had changed my rear gear fluid out just about 2 months ago and it continued to do it. Its not a left nor right thing its coming more from the center and only does it when my truck is under load. Meaning when my rear end is squatting at a certain RPM taking off. No wobble or wheel play at all, I was pulling my 2000 pound trailer yesterday and it did it more than ever since the weight was holding down the back of the truck. It does it up until about 20mph and stops. I hate being the only one to ever have this problem out of a million f150 trucks... lol Its aggrivating. I brought it to my mechanic and he heard the noise when we drove it. But when we put it on the lift it wouldnt make the noise and he said if it was a bearing it would make a different noise and it would continue to make it even after I left off the gas pedal.

 

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I forgot what I used but it was supose to have the additive in it but I added extra. It made the noise prior which is why I had changed it. I put the truck in neutral and it didn't make the noise. Could it be the tranny mount because when I move the muffler the tranny moves a little along with the driveshaft. Is that normal?

 

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Anyone know where to order a new slip yoke? I don't see any at autozone unless they are called something else. I put it back on the lift and noticed play in the slip yoke where it enters the transmission. I guess that might be my problem. Tranny isn't to bad but does have a tad of play which I'm going to look into correcting too.

 

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