Topping off rear diff through breather

Hey all,
I have a 2006 with a 3-inch lift, and is shimmed in the rear axle with 2.5 degree shims, I believe, but now the back end is tilted so I can't fit the 3qts of diff fluid. It begins to ebb out around 2.5qts. I tried jacking up the end and filling it that way but to no avail. I heard you can park on a steep hill and do it that way, but out of convenience I was wondering if it was possible to top off the fluid through the breather? Has anyone tried this before? Many thanks!

 

Way too thick, more would end up on the ground. You'll need the injection tool from a tool store.

 

Ah ok, so I could fill it from the breather if I get something like a gear oil fluid pump from Harbor Freight?

 

Honestly, its fine. I'd leave it. I was confused on your point.

The fluid capacity isnt exact, I've never known how much they take, I just bulk until it pukes out, and we do it on hoists where the axle is rotated upwards as well.

I think if you did jacked up, its good.

 

Don’t overthink it. You wouldn’t be able to tell the amount through the breather anyway even if it were an open line. Get it close enough and leave it. These aren’t an exact science. If the fill level is when it spills over, then consider it good like horseshoes and hand grenades.

 

You think so? I try and go by the book, but I was wondering the same thing because it definitely has "enough" oil to fling around in the housing, but I just want to be sure my baby is good, lol. I did do it jacked up and I even held a shop rag underneath the fill hole and tried to push/contain as much as I threaded the fill bolt. Thanks for the insight!

 

Put rear end up on ramps, let all the air out of the front tires. Fill, add air to front tires, drive off ramps.