I have Ten Factory fronts and yes it is a passenger side that is leaking.

 

Could be the seal but could also be this:

Axle on left is a 10 factory and the one on the right is the stock axle. Note how the Seal race goes all the way to the teeth on the stock axle but on the 10-Factory it is about 1 1/2 inches from them. The diameter of the stock axle was about 1/16" greater where the seal was riding on the factory axle. This caused mine to leak pretty bad. I spoke with 10factory and they sent out a new axle with the correct machining.

I guess they had a pretty big batch of the passenger rubicon d44 axles get out with this problem.

Anyways pull the axle, if it looks like the one on the left, call 10Factory, if it looks like the one on the right, your seal is bad.

 

Awesome! Thanks for the heads up on this. Pain in the ass if this is what caused my issue!

 

Did you have to replace the seal as well or did the new shaft fix the issue?

 

The new shaft fixed it for me.

 

Power washed it all out and drove for a good half hour. Parked and this is what I found

 

Like everyone has said it is probably the inner axle seal that has gone bad, problem that happens to many of us. Clean the lower C with brake cleaner and see if it continues. Like mentioned before the gear oil will probably be sprayed all over the wheel well. Mine went after I put HD ball joints in guess I wasnt careful enough putting the shafts back in. If that is the problem and the shop wont help you out with fixing it, it really isnt that bad of a job, $10 in parts but $400 labor if you have someone else do it. Here are a couple write ups to help.

POINTER: When you re-install the axle shaft, wrap the splines with plumbers tape before sliding back in. This will prevent damage to the new seals and will not damage your gears at all. Let me know if you have any questions as I just did this a couple weeks ago, hardest part was taking out the carrier. Hope this helps.

Replacing the Front Inner Axle Seals on a '99 XJ Dana 30 Axle. I made it at TechShop.?

D-30 Axle Shaft Seal Replacement - 1

 

Thanks for the advice. Ill look into it all

 

Will new axle tube seals fix this or no?

 

If you install axle tube seals it is only masking the real problem. After all the work it would take to install tube seals the only thing left at that point is to pull the diff cover and carrierm press the old seals out and the new ones in. Do it right the first time, you would kick youself in the a** if you let your housing run dry and tear up those expensive gears.