Diff oil change after gear swap

Recently swapped out my 4.10's for 4.88's on my JKUR. At the same time I had the shop put AEV diff covers on, the ones that have fill holes that supposedly take all the guess work out. I was following Eddies write up on here to double check the fluid volumes and it's taking quite a bit less than what Eddies saying. Is it possible because of the different gears and and covers (thicker) that it could take less?

Front took right at 1 quart and rear took a little less than 1.5 quarts.

It could but you don't want to over do it because the gears will splash the extra out of the breather tub and can actually suck the fear oil out. So once it starts to overflow, you're good.

When in doubt, you can always use a zip tie as a dip stick and physically do a check. Your gear oil should be sitting at about the base of your axle tubes. Any more and it's too much and your gear oil will start pumping out the breather hoses. Any less and you will fry your axle bearings.

wayoflife said:

When in doubt, you can always use a zip tie as a dip stick and physically do a check. Your gear oil should be sitting at about the base of your axle tubes. Any more and it's too much and your gear oil will start pumping out the breather hoses. Any less and you will fry your axle bearings.

Click to expand...

I pulled the factory cover off the shelf and compared the fill hole to the AEV "level checks" and it's right on. And like you said, even with the base of the tubes. Just surprised at how different the volumes are. Breathing easy again. Thanks!