You better pray it's not a pinion seal . Sounds like it's just venting but odd that you notice it at 80k miles. Mine vents for awhile after a fluid change and then stops. Heavy g's on a track will also cause it to vent more fluid than normal. If you have to swap the cover get one of these once you have all the rtv scraped off. I love these things. http://lubelocker.com/products/products/view/3/6

 

I use the lube locker gasket too. However, I did notice a small amount of oil leaking so I re-torqued the lower bolts a few weeks ago. So far it's holding.

 

I think its a pinion seal... How bad is it? How expensive to fix? It does not look too hard but really inconvenient without a lift, doing it on the street under the car... I took the vent off, and I was able to blow the air through it. I think there is some mechanism inside that takes some pressure at the beginning but then the valve opens and the air flows easy... I am sure its not the vent leak though...

 

Pinion seal is not easy if you have never done it before. First you have to take the pinion bolt out and then slide the flange off. Then pry the old seal out. Then take the old crush sleeve off the pinion and replace it with a new one. Put the new seal in and be careful to put it in flush and straight. Then comes the hard part...... you have to put the pinion flange back on and adjust the preload to Ford specs. Basically you adjust the preload so that it takes so many in-lb of torque to turn the pinion shaft with the differential unloaded. I don't know what the preload is on this pinion, but if you have never done it before, you will want to take it to a pro. Getting the preload wrong will cause all kinds of problems and it is a little tricky. I have done it before and it can be done, but it is not "easy". The car I rebuilt the differential in had a 17 in-lb of preload on used bearings, but that was on a 65 Muscle car.

Depends on how mechanically inclined you are and how much car work you feel comfortable doing. Doing it yourself will be cheap, probably $25-40 in parts (seal and crush sleeve), but doing it yourself and getting it wrong will be expensive.

Some people will suggest just re-using the old crush sleeve.... please don't do that.

 

What about the TSB?? 10-3-7
• REAR DRIVE AXLE VENT - OIL LEAK

 

Just called the local dealer, its 260$ labor and the seal...

 

Just my $0.02, but it would have to leak pretty bad before I dropped $260 to fix it. If it is just "wet" and not dripping, check the level once in a while and leave it alone.

 

Wow, that's not bad. I would think it required a full removal of the carrier/pinion and all the work that entailed.

IMO, get it fixed. Pulling the fill plug and sticking your pinky in there to check the level every few weeks will be a pita ;-). And you really don't want to take any chances with your rear differential.

 

I agree with 90Stang5.0 - however, I cant get the fill plug to turn, and really tight and I cant get any big wrench in there, not much clearance under. I will try to get some bigger wrench tomorrow... I wish I had some pipe to extend the handle or something...

 

1/2'' drive ratchet extension, Put it on jackstands and lower the axle if you need more clearance. who was that guy that used red locktite on his fill plugs, posted to the site?? lol maybe you got his old car.