Hey guys, I have a 2004 F150 Fx4 with 163K miles on it that I just recently (roughly 3 weeks ago) noticed was making a scrubbing noise. I noticed the noise when passing by objects that were close to the road and the scrubbing kept getting worse and worse and at some points was starting to sound more like a squeal. Well, my first thought was that it was my rear brakes, so I replaced the rear pads, checked and cleaned the parking brake shoes, which had a little build up on them from lake water. Noise was still there and as bad as ever. My next move was to take it to a small garage in town that told me I had noise coming from my differential and that such a job was too big for them to handle (they did however replace my front wheel bearings). So two weeks ago I took the truck up to the Ford dealership who replace my Diag. R&R carrier bearing, cups, and pinion bearing. I took the truck home and at first the noise was gone, but then came back. So I got back to my house and immediately noticed the awful smell of the limited slip additive so I looked under the truck to realize that my Pinion seal was leaking. So I took it back up to the Ford place on my way out of town and the mechanic there told me that it would be fine for me to drive on for the week but to bring it back when I got back into town. So I took my truck in monday morning, where they replaced the Flange. I finally thought the noise was gone when I heard it again this afternoon on my way home while making my way through the neighborhood. The noise is much quieter than it was before they replaced my Flange and the noise now only seems to happen after I brake from around 50-60 mph, but after I brake the noise continues until I shut my truck off and let it sit for a while. Any advice, suggestions, or ideas would be greatly appreciated. Ive already dumped nearly $1500 into this and I am getting tired of wasting money.

Thanks,
Garrett Evans

 

You pretty much replaced everything in the diff that could cause the noise.

Let me hit you with a couple questions anyway.

1. Are you SURE they put in the friction modifier, or did you just smell the gear oil? (which also smells kinda disgusting) I assume the dealer would know to put it in if you have a limited slip diff, but you never know.

2. Is this a noise you just hear, or can you also FEEL it?

3. Does it make the noise when travelling in a perfectly straght line, or turning, or both? The reason I ask is that you'll only hear noise related to clutches, or friction modifier when you're not going straight. When going straight, the whole carrier is turning, but not your spider gears.

Having said all this, I kinda doubt the noise is caused by anything in the differential.

Could it be your e-brake hanging up, or something?

 

I myself did not change my fluid, they did that after they rebuilt my rearend, at least that is what the receit says. I do not feel the noise when driving, as a matter of fact other than me just being frustrated that I can't make the noise go away, Im not sure if its causing any harm at all. It makes the noise all the time AFTER I brake from around 50-60 mph. I checked my parking brake drums and, other than some build-up that I believe came from lakewater, which I cleaned off, everything seemed to be fine.

Thanks,
Garrett Evans