Front axle leaking gear oil

My front dana 30 is leaking from behind the 3rd member housing, I think that us what it is called. Anyways it is where the driveshaft comes out the rear and it is leaking really bad. Any ideas what it could be.....maybe a bad seal??? Is this something I could fix myself or should I enlist the help of a shop? I am comfortable with major wrenching, but I know absolutely nothing when it comes to the ring and pinion and all the internal workings of the axle. Anyways what do you guys think.  
I am awesome at breaking stuff....fixing it is another story!

may be a pinion seal, their pretty easy to change, also check and make sure the vent hose isnt clogged, this will cause pressure to build up and it has to go somewhere, wich usually means out the seals  
"WHEN IN DOUBT TACH IT OUT!"

Even a lot of the magazine editors don't know what that is called. The gears and differential are located inside the "center section". The third member is the entire axle housing. The first member is the engine. The second member is the transmission.

Anyway, you're talking about your pinion seal. A couple other things could also be happening.

First, it could be over-full. Pull the fill plug out of the differential cover. The fluid should be right at the bottom of the fill hole, but not running out when sitting on level ground. If it is over-full, somebody did it, or it's taken on water. Not good.

Second, it could be a bad seal. Maybe the seal is just worn out. But it could also be damaged because of some other issues. Grab hold of the pinion yoke and try to move it around. It shouldn't move at all. Look at the front drive shaft for any damage. If it's not running true, it can wear out bearings and seals.

If everything looks ok, you can try replacing the seal. But it takes a couple of special tools.

You need to be able to hold the pinion while torqueing the pinion nut. That requires a yoke holding tool. You'll also need an inch-pound torque wrench and a foot-pound torque wrench. If you have access to these tools, it's easy to do. But there are some procedures that must be followed.

The seal is located behind the pinion yoke. There is a crush sleeve that sets the pinion bearing pre-load. Anytime you remove the pinion yoke, a new crush sleeve and a new pinion nut must be used. It is critical that the pre-load be measured with an inch-pound wrench before you remove the pinion nut. The pre-load must be reset to the same amount.

If you want the procedures, I'll forward them to you.  

Ya know, I never thought about the breather hose. A few weeks back the little plastic piece broke broke off and I replaced it with a cheap vacuum hose connector. I clamped this to the hose and put it back into the hole with a hella bunch of black gasket maker. Maybe I routed the hose wrong....wasn't quite sure where it went so I ran it straight up and it is zip-tied to brake fluid resevior. Now today, it doesn't seem to be leaking. Not sure what's up, But just in case it is the pinion seal, I can rent the tools at the on-post auto center and a bay for less than $10/hour. I'll perform the noted checks and get back to ya's later. Thanks!  
I am awesome at breaking stuff....fixing it is another story!

Ftgiles, I have a slow leak on the front and rear. Can you foward the procedures?  
2001 TJ Sport
- 4.0L I6
- Sport Wheels w/ 30 x 9.50
- Half Steel Doors
- Soft Top
- Daily Driver
- Standard Tranny
- 3:73 Gears

This is for the Dana 35 rear. The Dana 30 front is the same, but the initial torque on the pinion nut should be 150 ftlb not 200. The Dana 44 does not have a crush sleeve, so you can just replace the seal and torque the NEW nut to 175 ftlbs.




 

I have an 89 YJ and it's leaking there too. Do the same instructions apply? Do I have a crush sleeve? Any idea where to buy the tools needed? I saw on a website that they sell pinion bearings, do I need to get those? Sorry about all the questions, I've never done work on the axles or differentials before. Thank you.