OK, first...I was going to search for this, but there is no search link??

I bought a used ORU aluminum diff cover for my 11.50AAM of ebay for $50. I only got the cover, no "instructions", no bolts, just the cover and plugs. Being I had no instructions, I can only assume they may have had the estimated fill capacities listed...

I know the cover is deeper and that the fill plug is nearly an inch higher than the one in the OE cover. Saturday I installed the cover and 6.5 quarts of RP 85w140. Drove it around 300 miles and had no leaks.

Yesterday I checked the level...I assume you fill till it runs out the fill plug because the boss that the plug is in is really too deep and too small to get anything in there. I added another 2 quarts of oil (roughly 8.5 quarts total now) to get it "full"...

I assume that some fluid ran out the axletubes into the hubs...does 8.5 quarts sound right? Seems excessive to me...I figured the initial 6.5 quart fill was about right and then got wondering about the additional two quarts...that's a lot of oil.

Anyone install one of these on an 11.5AAM before or have capacity of the 11.50AAM ORU cover?? Just double checking...doubt there's anything wrong, but just wondering if this is normal?

Thanks,
steved

I have one on a Ford 8.8 in an f-150 and a set on an 03 F-250 D60 and god knows what in the rear. All 3 hold a bunch more fluid than stock. The damn 8.8 holds over a gallon and has the oem filler in the casting.

Could be correct.

Thanks, it's just hard to imagine almost doubling the volume of the diff...the cover didn't look THAT big...and there is a lot of "stuff" taking up room in the diff itself...

One thing is for sure with that extra volume and the aluminum cover...temperatures are down...probably won't need to change fluid for 100k. Before, I couldn't lay my hand on the diff after a 50 mile run, now it is just very warm to the touch.

Thanks again,
steved