i found leaking from my rear diff and without taking a second to check it out i automatically assumed cover gasket. so as you would expect i was a lil puzzled when i took a second to get under there and have a looksee. my 94 4bangin pu doesn't have the traditional cover i thought it did. so my question is, me being a newbster and the most complicated work i've done on my truck is replacing the front cv axles not with ease, would replacing the rear diff gasket be something i could figure out myself (given, i have to take the diff housing off from on the nose end instead of the traditional simple cover removal from the tail end). thanks in advance and add any tips you think would be helpfull.

 

Well..
You gotta pull the axles (8 bolts on both sides of the axle)
Andd then the 12 or however many nuts that hold on the 3rd member.
It's not hard, but the parts are heavy.

 

Where exactly is it leaking from? More common spot is the pinion seal..

Don't need to remove anything but the driveshaft and pinion flange for that one.

http://www.4crawler.com/4x4/CheapTri...eal/index.html

 

http://www.ncttora.com/fsm/1990-1995...f/assembly.pdf

http://www.ncttora.com/fsm/1990-1995...e/rearaxle.pdf

 

not really sure where it's coming from cuz the wind flow from driving has spread it everywhere. i'll have to clean it and let it sit for a while, but it could be leaking from both gasket and pinion seal. another question if you don't mind, could low gear oil in my rear diff cause my engine light to come on?

 

The diff fluid cannot trigger the CEL. No sensor back there for that. Here is how you can see what the light is on for though. The diagnostic connector is under the hood next to the fuse box, just need a paperclip.

http://www.troublecodes.net/Toyota/

Also, check the differential breather on the top of the diff. Stock it is just a small cap that closes from suction when needed. If this is clogged though, the pressure in the diff can build and cause leakage through the seals.

 

Link in my sig. There is a picture and step by step thread on removing the diff.

X2 on checking your diff breather.

Have you tracked down the leak to be sure it's the diff seal itself and not from the pinion or outer axles?

 

Its kind of rare to just thave the diff gasket start leaking, especially as bad as you are describing. I'd bet on the pinion seal, which can go bad if you have bad ujoints or a vibrating driveshaft.

 

Spread it everywhere? As in all all underneath the bed? If that's the case, it's the pinion seal. Leaks out and the driveline throws it off everywhere. Good for under the bed, but not great for the diff. If the mating gasket were leaking, it would be more noticeable all over the bottom half of the diff housing.

X3 on diff breathers. If that doesn't remedy it, then it's time for a new seal.

The only other way for a diff leak is through the axle shafts. Then, you'd have gear oil all inside the drums.

 

i got the pinion seal exposed now and can see that there is a thin reddish rubbery cover on the medal part of the seal that is torn to shreds. but i don't notice that same cover on the pics of yours or the new one so i'm kinda confused. btw the breather seams ok, and thanks for all your help.

 

I just replaced the pinion seal on mine...very easy fix, just check the flange to make sure its not scored anywhere...if it is, replace it or you will have another leak! Also, invest in a seal puller...$8...makes the job a lot easier.

 

picked up a new seal from kragen, tested the fit on the flange and could tell right away that it by comparison the old seal was too loose. followed AZ's, instructions from the link about changing the seal and presto. new seal is on and truck was taken for a test run. i cleaned most of the diff so i'll see tomorrow if it's leaking from anywhere else. thanks everyone for the help! this site rocks! what would us newbs do without you guys. thanks!

 

Go to a mechanic?? Buy a Honda??

 

Honda's don't break?

 

Glad the link helped. They aren't my pics, just one of the better write ups I've seen for the pinion seal.

How's it going, no leaks?