Differential Leak
 

I have a slight leak on the right output seal of the rear differential housing. I noticed it before I installed my new springs and sway bars, but I cleaned it and just rechecked it. It isn't dripping, but the entire area around the output has a film of oil that extends about 2-3 inches (6-8 cm for our metric friends). It has only been about 100 miles since I wiped it down. Has anybody changed this seal, or know how big of a job it is? I could use warranty, but I am an avid do-it-yourself kinda guy. Plus, I want to go back with the same fluid I have in it now. If you've done it, please let me know how big of a pain it is.

If your car is stock height, I'd highly advise you to go to the dealer.

The last thing you want is premature failure of the diff from fluid loss, and for corporate to deny you coverage because it wasn't documented.

If it's lowered... well, only way to fix it is to drop the diff and replace the seal if you want to DIY. Otherwise, you'd need to find a friendly dealer as this is one of those gray area claims.

-alex

How does lowering affect the differential? It leaked before I lowered.

That's what I'm getting at...

1. Seal leak should've been fixed before you lowered the car.
2. For purposes of warranty claims (and to make sure you don't screw yourself over on this in the long run), you should've at least had a dealer look at the issue and put it in writing prior to lowering the car

As for how it affects the diff... it doesn't. But a lazy dealer will use this as an excuse to get out of giving you a free seal replacement, and make your life more difficult should you choose to have it replaced at no cost to you.

But if you have all the time in the world and don't mind doing it yourself, you should be able to swap it out in about 2-3 hours assuming you can bench press a diff easily with 2 extra hands.

-alex

I replaced the seals twice when I rebuilt my diff. The first was to replace old seals and the second time was to replace a leaking seal similar to how you describe it (That pink stuff is diff oil):

http://i.imgur.com/E2aFild.jpg?1

It's not that difficult to replace that seal if you are comfortable working on the car, but it will take a few hours if you've never done it before. By the time I was done doing diff work, I could completely swap diffs in about 2 hours, so it's not really that difficult.

Since the leaking seal is on the passenger side, you are in luck and you may only need to unbolt the diff, remove that one axle, and then replace the seal from under the car. Removing the axle is the most frustrating part. You have to compress the passenger side shock and drop the diff in order to maneuver it just right to get the axle out.

After the axle is out, you just pry out the seal with a screw driver. To put the new seals in, I used a hammer and a socket and lightly tapped around the perimeter till it fully seated. A little grease on the outer edge helps. When you are done, be sure to use a multipurpose grease on the seal as per the manual. The cir-clips on the axle are supposed to be replaced, but I just bent them out a bit and reused them for the install.

This DIY goes through the whole diff rebuild process, including removing the axles without touching suspension bits:
http://www.ft86club.com/forums/showthread.php?t=54054

If you go to the back half of the thread, I added some tips on the process (such as using a bearing splitter instead of a pry bar to remove the axle).

Bumping this thread.

Few days ago, I jacked up my car from the rear differential point to change my winter tires. I've been using that same jack point the past 3 years of car ownership and no issues. This time around, after I changed my winter tires and lowered down the floor jack, I noticed rear differential oil on my floor jack.

I can't pin point exactly where the oil is coming from, it seems like the silicon seal housing the rear differential needs to be replaced?

Summary:
Monday - Jacked rear diff, changed winter tires, rear diff oil on floor jack.
Friday - No oil leak for 4 days as I put a cardboard on the ground until today. Looks like a few drips and nothing excessive.