Hey all,

I have an issue that hopefully someone may have experienced before. I own a 2003 Ford Explorer with Auto 4WD. I have been hearing a grinding sound from the rear end of the vehicle for a couple of weeks. The grinding sound is really noticable when I am coasting (Not Accelerating). It sounds like a Ruh.. Ruh... Ruh sound that speeds up and slows down in frequency with the vehicle speed at low speeds. Faster speeds above 40-50MPH you cannot hear it.

My Parking brake has not worked in some time so I thought most likely the pads were bad and rubbing inside the rotor. I removed the rotors and when I did the pads fell apart. I thought for sure this was the issue. I replaced the pads and reset the adjuster but the sound is still there. This had no effect on the grinding sound.

The only other issue I notice is that I have an ABS light on and when I accelerate faster than normal I can feel the 4wd kicking in. I know this may be a bad speed sensor and will replace soon. Could this be contributing? I believe the sound started soon after this ABS light came on.

I have new tires and feel no vibration in the steering wheel so I do not feel that its the tires. It sounds more like a grinding sound.

Any thoughts?

 

check the wheel hub bearing assembly

 

i would have guessed wheel bearing / hub unit also if you were not talking about brakes and ABS... wonder if that is just a second problem and not releated... did it do the ABS thing prior to the grinding noise? Jack the back end off the gound a couple inches and rotate each wheel and try to wiggle up and down.. any difference in the two sides ? I have had to take the wheels and brake caliper off before to figure out which bearing/ hub was bad. Sometimes its not that obvious if it is just starting to fail.

 

I am starting to think that the ABS is a secondary issue. I cannot recall if indeed they started at the same time. I did jack up the back end and wiggle the wheels and fouind no significant play, however, like you said I may have to remove the brake assy.

I have an appoinment at the dealer Monday for them to help me diagnose the issue.

 

So I took it in to the dealer yesterday. Grinding sound is definitely coming from the rear diff. Dealers words were "High Dollars" to fix. I am going to look for a used Diff at a local Boneyard. Any thoughts on how hard it will be to replace? Dealer also told be the rear diff ABS sensor is the one faulted and that the two were most likely related.

In the meantime I plan on changing the fluid and see if that helps to quiet the noise a little.

 

UPDATE...

I took it to several places for estimates and ended up going with my local Aamco who rebuilt the rear diff and replaced the ABS sensor for $1,100. I thought this to be amuch better deal than buying used unit and no Warranty. I got the explorer back in two days and no more noise..