Front differential puking fluid
 

I'm having a strange problem with my front differential. I damaged my stock cover a few years ago and replaced it with a Solid cover. Added too much fluid the first time and dealt with it puking out the breather tube for a while. No big deal. Fast forward a year and it starts puking fluid out the breather again for no apparent reason. I made a dipstick to measure the fluid at roughly the bottom of the axle tube and found it was low. Added some fluid, saw a little additional puking and then it settled down. Now, all of the sudden it started puking again. Once again, the fluid seems to be below the bottom of the axle tube.

I'm at a loss as to what the heck is going on. Can anyone offer any suggestions?

Thanks!

Complete guess but could it be that the fluid is the wrong viscosity? Did you use the recommended fluid when you changed it? Or maybe the fluid needs to be changed since as the additives wear out the viscosity when cold changes.
Can hurt to try changing the fluid and see if that fixes the problem.

Good point. I'm running Mobil 1 synthetic 75W-90 front and rear. The manual calls for 80W-90 (or 75W-140 in the rear for towing). The viscosity I'm running should not cause a problem versus the recommended factory fill and is pretty much considered a direct replacement. It's also worth noting that I've had no problems with the rear diff, just the front.

The gear oil is less than two years and old (and the front has leaked a lot and been refilled) so it should still be in fine shape.

Any other thoughts?

Sounds to me like there's pressure building up in the diff some how.and then it releases I would inspect the
Breather hose for kinks or plugage. The little one way valve on end of hose...

Don't think this the problem, but are you running air lockers. Have seen this when an air leak into diff forcing up the breather.

Nope, no air lockers. The plastic piece on the end of my breather tube us just a tube. No check valve. I'm guessing a part has gone missing.

What about water getting in ? How are the seals doing ?

I would remove the cover to see if there is water in there and fill with correct amount of fresh lube.
Cheap piece of mind....

Seals seem to be good. Besides, we don't get much water here in Southern California!

Have you taken it anywhere for service , they might have filled it without telling you