REAR-END Humming Noise !

[JMDetermann]

I have a 2001 Sport trac 4x4 w/ 65,000 mis.
I am experiencing a problem. I can hear a humming noise comming from the rear-end. I took it to a mechanic who said he didnt find any metal shaving on the magnetic cap, however the rear end fluid was low. I stopped by Valvoline on the way home and they topped it off with the correct synthetic fluid. They said it was about a quart and a half low.

The sound was a bit quieter, but still was noticably louder than it should be.

About a month has past and it has again gotten even louder. Im pretty sure if I go get it topped off again (which valvoline does free of charge) it will quiet it some. But there is obviously an issue here.

Anyone have any thoughts?

-Jon

[JMDetermann]

ALSo I forgot to metion it seems loudest when aat about 30 mph.

I only hear the noise when I am applying pressure to the gas pedal. When I let off it goes away. It is for sure comming from the rear end and not the tires.


I think maybe I meant a Pint and a half low. (not a quart and a half.)

[colannino]

I had a humming from the rear and it was my rear bearings that neede to be replaces. Cost me about $400 at the dealer.

[Kaobb]

I had rear end noise. The gear mesh was never right from Ford. The rear end had to be replaced for about $900 if I remember correctly.
Sorry to tell you that. They have had numerous problems with rear end noise.

Hope yours isn't as drastic but it doesn't sound good to me.
k

[denisb]

You say if you top it off it will reduce the noise. Then there is fluids leaking somewhere. That's your #1 problem. Then if the fluid isn't leaking around the plug or the pan, it's probably leaking at the bearings which could explain the excessive hum. (not sure if the Xs have pans, I never even looked at mine )

Denis