I have a 2002 explorer with 50,000 miles thought it was the tires making a humming noise at around 30 mph when I go above 50 noise dissappears,is there a problem like I have been reading from others that there could be a rear end issue? can changing the rear end oil help?
thanks

 

many of the EXP after 2001 with the independant rear suspension have a gear mesh noise. the frequency noise normally shows up at 55 mph and goes away at 65 mph. it is not a bad bearing if the noise goes away above specif speed. Never heard of one that did it at 30 MPH. If it is the mesh, you goal is to change the viscosity, sticky ness of the lube, etc, to try to get the noise to change at 60 MPH crusing speed. I have changed the lube to 75-w-140 and added friction modifier with good success.

 

thanks for the info big help

 

If you are sure it is coming from the rear, you could have a bad wheel bearing back there.

 

I noticed that if I turn the wheels to the right while driving the noise goes away is there something else I should look for? when I go straight or turn left its more noticable.
thanks

 

Your problem sounds like it is on the passenger side of the vehicle. When you turn the wheel to the right, you take the load off the right side of the vehicle so the noise gets quieter. When you turn the wheel to the left, you are putting more of a load on the right side of the vehicle so it makes more noise.