rear end roar

[justinf89]

I have a roar coming from the rear end, that really doesn't get louder with speed. I jacked up the rear end and turned the tires by hand, and on each, I can feel a bump when it rotates. Both rear tires do this. I tried the 9-3 oclock rock but really couldn't tell if they rocked or not. I'm about to change the rear diff fluid and I heard that to change the rear bearings, you have to access the inside of the diff and that fluid isn't cheap. Anyway, any ideas?

 

[BK_89iX]

I had some noise from back there, so like you I changed the fluid as a first step. Did not solve anything. Found some gold metallic particles. Went back in again after learning more, and what to look for, and found the carrier bearings to be totally shot - that explained the gold particles - overheated bearing material. Check out my threads in the tranny/diff section. My axle bearing surfaces looked OK, but I replaced them anyway (axle shafts and axle bearings) for good measure. If the tag on your diff calls for 75W140 SYNTH it'll be about $18/quart, so it's best to go in just once to minimize expenses.

To answer your question, yes in order to inspect or remove the rear axle shafts and rear axle shaft bearings you need to first drain the differential, remove the cover and remove the C-clips.

BK

--> link to my differential project: http://www.explorerforum.com/forums/showthread.php?t=272694

 

[my pos mounty]

I have a roar coming from the rear end, that really doesn't get louder with speed. I jacked up the rear end and turned the tires by hand, and on each, I can feel a bump when it rotates. Both rear tires do this. I tried the 9-3 oclock rock but really couldn't tell if they rocked or not. I'm about to change the rear diff fluid and I heard that to change the rear bearings, you have to access the inside of the diff and that fluid isn't cheap. Anyway, any ideas?

It isn't all that difficult to change the axle bearings in your differential, if that is the source of your "roar". A little time, some elbow grease and a rental slide hammer would be all that is needed.
Diff fluid is diff fluid, nothing extraordinary and if your going to change it anyway, why not address the problem at the same time?
There is only one true way to find out if you need axle bearings, other than if they are so gone that they create "slop" or movement. That is to take the axles out of the differential and check them out.
I suppose that the axle bearings could be the source of your roar, but I think it is more likely the carrier bearings or the pinion bearings because those are a much more common problem with the Ford 8.8

 

[groundhogeez]

options

I have a 2000 AWD 5.0
The rear end is roaring as well. I have already changed the fluid and a pinion seal a few years ago. I think I over-crushed the pinion washer in the process.

So: I probably screwed up everything and with 145,000 miles what should I do next ?
1. Take it apart and fix it.
2. Get a re-built 3rd member.
3. Take it to a shop.
4. None of the above.

Thanks for any advise offered.