I filled my 8.5 diff tonight. I put just under 3 quarts of 80 / 90 w gear oil with GM limited slip additive. Does putting in almost 3 quarts of oil sound about right? I have an after market diff cover and was wondering if maybe the cover lets it hold more gear oil. Also, no gear oil ran out the filler hole.

http://i155.photobucket.com/albums/s319/jcgc_photos/100_2035.jpg

Man, can someone move this to the transmission and driveline section. :boring: when I posted this.

Don't know about the capacity...
But that garage floor is WAY TOO CLEAN! :) :) :)

Jim

John, friendly reminder, site policy asks that you size your photos to around 880 x 660 or less, this way folks dont have to scroll side to side and up and down to see the pics, AND alot of members are on dial up modems, the larger pics take forever for them to download, Thanks for understanding. :thumbsup:

Sorry, I thought I did resize before I posted it, but I guess not. Last night was a bad night.

WOW!....That's amazing that you were able to cram just under 3 quarts of that stinky, smelly gear lube in your 10 bolt!!.....You must have one big fat capacity aftermarket rear end cover!.....The normal capacity for the 10 bolt is 3.5 pints and 4 pints for the 12 bolt.

So, I need to add more? or is 3 quarts enough?

The capacities Ron listed are right, although the 69 GM service manual lists capacity of the 10-bolt as 4.5 pints; are you sure you added 3 quarts (6 pints)? The aftermarket cover is supposed to add about 1/2 pint more capacity, so you'd be in the neighborhood of 5 pints (2.5 quarts).

Regardless, it should be just at the bottom of the fill plug for proper lubrication, with the axle warm.

I know this is an old thread but I thought I'd chime in with what I just found out when I filled mine up. I have an 8.5 10 bolt from a 74 Nova out of the car. It has 3.73 posi and factory cover. I put it on saw horses and leveled it from all directions (front to back by leveling the flat rib on each side). I measured 3 1/2 pints (7 cups) into a bucket, put a 4 oz bottle of GM posi additive in and mixed it up real good. Poured all that in then added a cup at a time until it just reached the overflow. It took 3 more cups so 10 cups or 5 pints altogether. I'll check it again when it's bolted in the car permanently. If it's over filled I'll let it run out. I doubt if it will be low.
I started with 3 1/2 pints because I saw that earlier in this thread but that may have been for an 8.2 10 bolt whch appears to be considerably smaller..