Torsion said:I think that's a common mistake.
I too thought my '13 diff cover had a super-cool "fill hole" and "drain hole". But that's not correct... those holes are for a bolt-on diff oil cooler. Right guys?
The proper fill hole is on the main diff housing, not on the diff cover. Look for it above a "ledge" on the front, driver's side, upper half of the diff housing.
It's lower than the top hole on the diff cover.... so when you take it out you'll probably get some spillage.
You can fill the diff from wherever, but you need to check the level via the plug on the ledge on the front, top side of the diff. You should not use the top fill plug on the rear of the diff cover as your fluid level indicator. I usually fill it until it barely starts to run out of that front hole, with the axle fairly close to normal ride height