Humming Noise

[johnsa28]

I'm lost with the noise I have with my Explorer, there's a humming noise that starts at about 20 mph gets louder until about 40 mph and progressively gets quieter until it's almost unnoticeable at 70mph. The noise is also only noticeable under acceleration as soon as I start coasting it goes away. I think the noise is either coming from the middle or back of the vehicle but I'm not positive. So far I've changed the 2 rear wheel bearings, rebuilt the differential, and replaced the transfer case, I also changed the left front wheel bearing about a year ago, and from what I can tell I don't think it's either 2 of the front wheel bearings. It also has new tires so it's not from the tires cupping. Anyone have any ideas because at this point I'm lost.

 

[mikey4563]

its most likely your pinion on your rear diff. Sounds like you need to have your pinion replaced. are you getting a leak from the back as well from the pinion seals?

 

[johnsa28]

its most likely your pinion on your rear diff. Sounds like you need to have your pinion replaced. are you getting a leak from the back as well from the pinion seals?

I don't have a leak and I just had my rear diff rebuilt about 100mi ago and it didn't change anythingwwith the humming noise