Drone sound in rear

[MDmounty]

I've got a drone sound coming from the rear of my mountaineer. It happens when I get going about 55 mph and higher, so I hear it daily because I go to and from work on the highway every day. I took it to the shop today so they could look at my exhaust but that didn't fix the problem. I did some research and people are saying rear wheel bearings mostly. I'd like to get some more help before diving into wheel bearings. Thanks for any input

 

[Houlador]

The bearings are a good idea. First thing that came to mind are worn differential, ring and pinion gears. If they are not set up correctly when put in they can "howl".
Good luck and let us know what you find. Semper Fi Bro!

 

[XLTrunner]

Explorers are well known for their rearend howl. Mine had 150K miles on it last summer when I took it to the shop...where they confirmed the pinion gears & brgs were worn. Couldn't believe how quiet the truck ran after those were replaced.

 

[1998Exp]

Unfair to Explorers! 'Whining' that starts at 100K-150K is typical of the Ford 8.8" differential, which was used in dozens of different Ford models over 30 years or so. My 1985 LTD did that, and now my Explorer is heading the same way.
Incidentally, how much they charged you for the rebuild?

Explorers are well known for their rearend howl. Mine had 150K miles on it last summer when I took it to the shop...where they confirmed the pinion gears & brgs were worn. Couldn't believe how quiet the truck ran after those were replaced.

 

[XLTrunner]

I've never owned any other rear wheel drive Fords other than Explorers. Wasn't aware it has been a problem over such a long period of time and with so many models. Shame on Ford for not addressing this issue...

As for cost to repair...it ran me about $800. Hard for a D.I.Y'er to swallow, but I had no experience working on rear diffs and performing proper lash adjustment that is required.

 

[MDmounty]

That sounds like me I have about 180k on mine I'll have to look into it. Has anyone here done those gears before? I'm trying to see how difficult it is to do on your own

 

[Houlador]

It's fairly difficult . It takes micrometers (?) to measure clearances. Once everything is put into the rearend a yellow dye is put on the carrier gear. Turn the axles and the dye will leave a mark on the carrier gear. Or a pattern. This checks the pinion depth. To make adjustments more shims are added to put the pinion gear further into the ring gear, or remove bushings which pulls the pinion gear out, or not set as deep into the ring gear.
Google is your friend. Look up some videos or tech manuals to get a more complete idea than I described.

 

[lobo411]

Unless it's really bad, I'd leave well enough alone. My '96 has had a slight whine/drone since 105000 miles/12 years ago. Just crossed 170000 a few days ago. Still whining/droning, but no real problems.

 

[Flash]

Tyres can make a drone noise too.

 

[XLTrunner]

Not fully understanding how all that gearing/bearings work together inside the diff, I didn't want to push my luck by risking a much more expensive complete rebuild by ignoring it. Mine was pretty noisy, though...and, new tires didn't do anything to quiet it.

 

[SWIGIN]

My Ex has a very noisy howl in the rear. Mine never really goes away but really kicks in at 45mph.

If it makes noise all the time it's bearings, If it makes noise under light throttle most mechanics say this is a worn ring and pinion.

This tells me that my bearings are shot and I probably have worn gears.

I will just replace the bearings in mine and of course set the gears up as far as back lash and pinion depth.

I have done over 20 8.8 rears and some slight noise is possible even when everything is new especially with the lower ratios.

 

[Robman]

I had a 3.73 Limited Slip with excessive whining, in fact I bought the truck that way.
It felt like it was holding the truck back also.

I replaced the whole rear axle from a donor truck.
The new axle had a bit of a clunk going from forward to reverse though.