Rear Dana 44 Leaking Gear Oil Near Pinion Seal

I re-geared to 4.88 and had front and rear lockers done at the same time about 3 months ago. After the 500 miles of breaking in I changed the diff fluid on my own and since then there has been several times when traveling on the express way only that the gear oil blew out the breather tube of my rear Dana 44. Yesterday I was changing my diff fluid again (and there was some metal present from the gears breaking in, wasn't brown though). I ended up getting a little over 2 quarts out when I drained, so I suspect that I over filled the axle when I did the initial change. I assume that the gear oil was heating up at high speeds and because it was over filled caused it to come out of the breather tube. Again, this only happened when doing long trips on the expressway at 70-75mph.

So now the kicker, yesterday I notice that there is some moisture near the pinion seal on the underside of rear axle. It doesn't look like there is excessive loss, but enough to see noticeable discoloration on the metal. My question is this, is it possible that the gear oil go so hot and thinned out causing the leak from the pinion seal and breather tube due to over filling? Any other experiences that might answer why I developed a slow leak in this location? I don't think that it's constant as there wasn't any fresh oil, just the discoloration.

First off, I personally would recommend that you NOT over fill your diff - just fill it to what is recommended or to the base of your axle tubes. Anything more than that and you will get gear oil pumping out of the breather. As far as your pinion goes, you should not be getting any leaking there unless you seal is bad. You said you just got new gears installed - did you get new seals installed at the same time?

Yeah, I didn't mean to overfill the diff, it was done by accident as I was using a 1 quart bottle and didn't take into account that they probably weren't full to the top :doh: Going to look into a hand pump and plastic hose for the 4 quart bottle so I can be more precise on how much I put in.

Yes, new seals were installed at the time of my gears and lockers.

Can anyone verify that this is the correct part #JEP68004072AA for the pinion seal?

I'm having one helluva time trying to find the part locally and suspect I will have to go to a stealership. Also, how difficult is the repair? From what I've gathered it's removing the drive shaft, slinger, flange and nut. I'm running the stock drive shafts. Is there anything I should be aware of, like grease the new seal prior to installing the new one? Any advice would be most appreciated as I'm supposed to be leaving to go wheeling for the next 5 days starting tomorrow and I'm a little bit nervous :thinking:

i picked up pinion seals for my 2010 from NAPA - they were the only place I found that had them in stock