Rear Diff
 

Well guys, today looks like good weather and I am off tomorrow (I love federal holidays) so I was thinking about tackling my rear diff. I have noticed lately that it has a slight drip so I slid under there and it looks like it is coming from where the 3rd member housing meets the axle. Tons of gunk all over the axle and all over the breather. I cleaned it off but have a couple of questions.

What is going to be the best way to clean out the breather and make sure it still works correctly?

What's going to be the best way to replace that gasket? I haven't seen that specific gasket for sale around here. Would a tube of ultra black gasket maker do the job? If so lol, make the bead around all bolt holes and around the whole area, let it skin for 15 minutes or so. Put parts into place and barely tighten, let dry for 12 hours. Then tighten down how much? Or is my whole understanding of it off?

The vent just unscrews, remove it and clean it up, and replace. Toyota does make a paper gasket for the 3rd member, but when I replace mine, I use RTV or "HondaBond", and follow the directions on the container. The diff gets warm, but, its just keeping oil in there, there's no monster trying to get out.

If you wheel often the rocks will loosen the nuts on your bottom diff studs. I would recommend tightening them first and seeing if the leak stops.

Slid under the back and snugged down those bolts a little bit. There was right around a half turn on the bottom bolts before they were nice and tight.
About to go out and try and find a 24mm socket (only have a 21) so I can check the fluid level in there.

So I guess it does see some rocks, eh?

If this is a recurring problem you can replace the lower studs with buttonhead bolts or something like this http://trail-gear.com/images/diff-stud2-500.jpg

RTV is pretty hard to mess up.

I know I never go wheeling over rocks, you can't find rocks like that here in Ms. The most I have done is a little tiny bit of mud, nothing too big. I am guess just years of the PO not checking on things?

Did you check your breather? Mine got plugged up and forced the gear oil out the 3rd member/housing seal. Cleaned it out and snugged the bolts down, no more leaks :)

If you do however want to tackle replacing the seal, its VERY easy.
Took me an hour to change out my rear diff.

Short story that pertains to this.

A friends father used to take 3 or 4 hours to do an oil change on his truck and we used to give him crap about it. He'd crawl under the truck with a handful of rags, one plastic scraper, one can of WD-40 and a squirt bottle of CLP and clean the entire under carriage. He cleaned the motor, frame, springs, front and rear axles, tranny, t-case and every dang cross member under there. Then he'd drive it to warm everything up and while the oil was draining he scoot under there and check bolt specs with a torque wrench. He checked EVERY BOLT AND NUT! Then finish the oil change, grease everything and give it a complete wash. Now this wasn't some trailer queen. This is his Nissan work truck (I think it was a "Might Max") and to date he still has no leaks, original everything other than tires/belts/fluids and is sitting on almost a half a million miles. No joke.

Now I know this is extreme but given that your nuts were loose (no crude jokes please) it might be a good idea to crawl under there and check all the rest of them.

Just my couple of pennies.