So it’s time to do my 500 mile diff oil change since I had my re-gear done. I have a 4 inch lift, so my pinion angle is turned up. Should I jack up the rear of the jeep to fill the rear diff, or just fill it on the ground and call it good? I searched on the forum and all over google and didn’t find a definite answer.
Diff oil level pinion angle
- Thread starter Pugaroo
- Start date
Through the breather is also an option.
How ever you do it, as long as proper amount gets in, not more or less. I typically begin through the plug and finish through the breather. Sometimes i undo lower control arms, this is the easiest and fastest way.
How ever you do it, as long as proper amount gets in, not more or less. I typically begin through the plug and finish through the breather. Sometimes i undo lower control arms, this is the easiest and fastest way.
Here’s how I did it. Found a longer piece of tubing for my pump and went straight to the vent fitting. Stretched the tube with needle nose pliers so it would go over it. I filled the diff until it started to leak out and put in the plug. About 1.25 quarts. Hooked up the hose to the vent fitting and put in the other 1/2 quart. Watching for any leaks but nothing yet 
There's a YouTube video taken through a clear plexiglass differential cover that shows the absolutely massive curtain of gear lube the ring gear throws throughout the housing and toward the pinion gear bearings. Once you see that video you will never worry again about the gear lube level again due to the pinion angle having been raised.
Here's the video you speak of where Gale Banks explains the ring gear moving the oil with clear cover.