diff fluid level after shimming axel...

ok so i got done installing the proper shims over my rear axle (went from 2.5* to 4*). now as common sense would tell you i can no longer fit the same amount of gear oil in the diff as i once could... even if i jack the rear up as high as my jack can go it only makes like a .5* difference. i understand that the ring gear slings oil at the pinion so i know its not gonna blow up if i drive to work. should i address this? am i worrying about nothing?


BTW i have the c 8.25 with stock diff cover

All I know is mine has been fine for years I just fill it until its full and thats been fine so far.

Park it on a hill if you want to get a bit more it, or add more through the breather, but I think the oil gets slung around in there good enough as is.

The aftermarket covers have the hole a bit higher up to address this.

If you ever go 8.8 you can just remover the ford speed sensor, and pour it in through there.

dylan1650 said:

ok so i got done installing the proper shims over my rear axle (went from 2.5* to 4*). now as common sense would tell you i can no longer fit the same amount of gear oil in the diff as i once could... even if i jack the rear up as high as my jack can go it only makes like a .5* difference. i understand that the ring gear slings oil at the pinion so i know its not gonna blow up if i drive to work. should i address this? am i worrying about nothing?


BTW i have the c 8.25 with stock diff cover

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It won't matter. You haven't changed it enough to make a difference and everyone else who's ever done what you did is in the same situation. If you read the fluid volume specs on most rear ends the correct volume doesn't go to the edge of the fill plug anyway.

BTW, if you get an aftermarket diff cover for a rear application with a very high fill plug hole, for HP diffs, you don't want to fill it to the fill hole since the level will be way too high and you're likely to blow oil out the diff vent. Technically, you look up the diff fluid volume and put that much in and don't pay attention to the fill plug hole height, but I know most of us don't do that.