Rear Differential

[hill_jack]

Hi Folks,
New member here with a problem, I have a 2001 Explorer Sport 4x4 that I purchased used at 64000mi. Original problem noticed was r/r wheel bearing seal leaking and slight bearing noise. Replaced both and new gear lube.Also installed new u joints on rear driveshaft as one was starting to go. Although it quieted down a lot still had a whine coming from the differential and I highly suspect it to be ring/pinion bearings. The unit has 98000mi on it now and is in great shape other than problem noted.
Was just wonder if any one else has experienced these problems, are these rear ends a weak link??? and any recomendations??? Have repaired or better to replace whole unit from a salvage yard???
Don't shoot me guys!!!! I am a GM person at heart, thats why I'm here looking for info from people who "know" their Fords...
Thanks in advance for any help or insight !!!
hill_jack

 

[JDraper]

Welcome!

The Ford 8" differential is definitely NOT a weak point in the vehicles. It's a pretty stout axle, capable of supporting a considerable amount of horsepower or large wheels. It's possible that you might have bad bearings or the ring & pinion going bad, but that would most likely be due to something that the previous owner did to the vehicle.

Pop the back cover off the differential and take a look at the wear pattern and check for slop. Only thing it will cost you is a tube of silicone and a couple of quarts of gear oil.

 

[CDW6212R]

Welcome, and no the Explorer rear ends are very tough. You likely had damage throughout when you bought it. It probably lost too much fluid, or bearing material circulated into everything and hurt other parts. It sounds like the right thing was done back then, but now it shall need more.

The parts are not expensive, you should locate someone who can properly install ring and pinion gears in the 8.8 and replace the gears and all bearings. The axle bearing surfaces don't always last more than 100k, look at those very carefully. If you need different axles, than a whole rearend may be cheaper in the end, but not better. I needed two axles(bent) for my 99 rebuild(rollover), and a whole 98 8.8 with 78k was $150 here. Good luck,

 

[CDW6212R]

Don't use silicone, ever, please. That crap is good for bathroom floors, nothing else. Use only RTV(Ultra Black), it is not silicone, it is vastly superior. Regards,

 

[JDraper]

Don't use silicone, ever, please. That crap is good for bathroom floors, nothing else. Use only RTV(Ultra Black), it is not silicone, it is vastly superior. Regards,

News flash....Ultra Black RTV is a silicone based gasket material..... And is what I was suggesting...never even considered bathroom caulk.......

 

[CDW6212R]

I know it's origins, but using the "silicone" term in the prescence of any unknowing person immediately sends them to Lowe's for silicone. Please do everyone a favor and use the term RTV, which is far more accurate and appropriate. Regards,

 

[BryanB]

RTV= Room Temprature Vulcanizing. It's silicone.

 

[CDW6212R]

Try using silicone to seal an intake gasket, exhaust gasket, or any high stress location. Junk silicone that you buy at Home Depot etc. deteriorates extremely fast compared to automotive grade RTV. It turns to dry stiff non useful brittle junk in a matter of months exposed to high heat etc. Try using silicone on the top of a fireplace to seal cracks, it's junk. I have Ultra Black on my fireplace now from three years ago, and it is relatively hard, but still pliable and sealed, unlike the black tar crap that is recommended for roofing etc.

Learn to identify poor products, and avoid them. Do not confuse them with extremely high quality products, and don't suggest to others that they are remotely close in quality. Plain silicone is junk, and using simply the term silicone suggests specifically clear silicone, which is junk, Period.

 

[hill_jack]

Thanks For the info guys and you opinions! I can pretty much guess what I'll find when I look into it. I priced rear ends from the salvage yards at $300.
Will have to check on prices to rebuild also, and not that the mileage scares me but at a 100000 have been contimplating trading it in, so just want to keep the repair cost down to a minimum.
Again thanks for your advice,
Hill_jack

 

[CDW6212R]

Good luck to you, when taken care of the whole truck can easily last over 200k with no major issues. The rearends are the strongest points, while your SOHC engine and 5R55E trans does have needs, before high mileage. If you keep it search on the forum for "timing cassette*" and "transmission valve body kit". Regards,