Leaky rear differential. Big problem?

[4x4only]

I have a 2001 explorer sport and my rear diff is leaking right at the pinnon seal. I don't know how long it has been like this but it is pretty bad. It is all over the bottom, gas tank, diff, and drive shaft. When I park it for more than a few days, a puddle forms. Is it serious or should I get it fixed? There is no abnormal sounds from it. It is limited slip. I am worried I may damage it if it getts too low.
Thanks for reading please help

 

[imp]

I have a 2001 explorer sport and my rear diff is leaking right at the pinnon seal. I don't know how long it has been like this but it is pretty bad. It is all over the bottom, gas tank, diff, and drive shaft. When I park it for more than a few days, a puddle forms. Is it serious or should I get it fixed? There is no abnormal sounds from it. It is limited slip. I am worried I may damage it if it getts too low.
Thanks for reading please help

First be certain the leak is originating at the pinion seal. If you are, then as the leak continues, and gets worse, the diff. will be getting low on oil. Plus, the stuff stinks terrible, to get all over the place, UGH!

A guy who knows what he's doing can replace that seal in a relatively short time. Most important consideration is that the pinion bearing preload be properly determined to prevent noise, bearing, possible gear failure. imp

 

[crunchie_frog]

I have a 2001 explorer sport and my rear diff is leaking right at the pinnon seal. I don't know how long it has been like this but it is pretty bad. It is all over the bottom, gas tank, diff, and drive shaft. When I park it for more than a few days, a puddle forms. Is it serious or should I get it fixed? There is no abnormal sounds from it. It is limited slip. I am worried I may damage it if it getts too low.
Thanks for reading please help

At some point, if the leak is bad enough it will stop leaking since it will run out of fluid. If a puddle is forming, you need to repair it ASAP.

 

[white_shadow]

i did mine last fall, diff fluid STINKS!! not a bad job. i also replaced the front pinion bearing while i was there. as far as preload, i just counted the number of turns it took to take the nut off, and put it back on with the same number of turns. been 12k miles, no problems yet. also, make sure you use the correct diff fluid with the friction modifier. i got the modifier from the stealership, ~12$ iirc

 

[DjDom]

Err, I'm surprised no one mentioned topping off the fluid.

I would fill it up with more dif fluid so it doesn't run dry. Cause then you're causing extreme wear on the internals.
There's a filler plug near the top. See if you can get it off, it'll take a bit of power. Once it's off, fill it up with the right fluid.

 

[white_shadow]

Err, I'm surprised no one mentioned topping off the fluid.

I would fill it up with more dif fluid so it doesn't run dry. Cause then you're causing extreme wear on the internals.
There's a filler plug near the top. See if you can get it off, it'll take a bit of power. Once it's off, fill it up with the right fluid.

because what you said is just plain stupid and makes as much sense as putting more air into a tire that has a hole in it. fix the problem, be done with it.

 

[imp]

because what you said is just plain stupid and makes as much sense as putting more air into a tire that has a hole in it. fix the problem, be done with it.

You reveal that basically, everyone is a bit stupid. imp

 

[4x4only]

I could probably do it myself, thanks for teh advice

 

[1996BLKBauer]

Mine does the same thing, just top it off every 2 weeks, and you will be fine, heck I even waited a month, and it only took like one pump, so even though the puddle looks huge, you are not really leaving that much fluid. I am waiting to replace mine in my Manual Trans, and drive train class, for the convenience of a lift.

 

[Carguy3J]

i did mine last fall, diff fluid STINKS!! not a bad job. i also replaced the front pinion bearing while i was there. as far as preload, i just counted the number of turns it took to take the nut off, and put it back on with the same number of turns. been 12k miles, no problems yet. also, make sure you use the correct diff fluid with the friction modifier. i got the modifier from the stealership, ~12$ iirc

Conventional gear oil stinks. One of the benefits of switching to synthetic is far less odor. Plus, Ford specs synthetic fluid anyway, at least for factory limited slip diffs (75w140, with LS additive) I use synthetic gear oil now, in everything, partly because of the lack of stink.

Your "method" above is very much wrong. Yes, if you re-installed the old bearing, then the same number of turns of the nut would get you fairly close to the previous pre-load. Of course, that's assuming the pre-load was set correctly prior to you taking it apart. You don't know that. Also, a new bearing changes everything, as does the new race that you should have also installed to go with the new bearing. You may have gotten lucky, and it may hold up. Or, 12k isn't enough for any problems to have become obvious just yet. Assuming you haven't opened the diff since, for all you know, the gear teeth could be in the process of getting chewed apart, and just aren't making any noise yet. Bottom line, that's not the right way to do it.

 

[4x4only]

Yea I thought it was weird that the oil didn't stink, I will have to use synthetic. I will get it done by a shop, just cuz I'm scared of over/under torquing the nut, but it costs $150 just for a compression test