I replaced my Dana cover gasket 2 times and it's still leaking. I cleaned all surfaces with brake cleaner then used permatex black/gasket/permatex black.

Not sure if this makes a difference but it seems like the GM additive (clear) is leaking first. I'd expect to see brown gear oil (85/140) but both times there's a light film of almost clear fluid dripping from bottom.

Thx

is it a steel cover? or a chrome cover? if it is chrome, take a soft grinding wheel to the sealing edge and take the plating off, you will know its good when you see the copper color underneath. then use some ultra black and put it on. never had one leak after that.

Is it a sheet metal cover?
If so, maybe the bolts have been overtightened and dimpled the cover just like on an oil pan.

It is an aftermarket chrome cover. It has pretty heavy ribbing, i'd be surprised if it's warped. I'd think the 2 layers of permatex would fill any gaps?

Maybe the permatex isn't bonding to the chrome? I did allow 2 days cure time before filling.

http://www.summitracing.com/parts/SUM-730310/?image=large

Any other ideas?

Thx

I have had Danas that leaked from the axle tube and the oil ran down making it look like the cover was leaking... Something to check out

I had the same problem with a new Mopar chrome cover on my Dana, it recleaned the axle gasket surface and then took a flat file and dressed the gasket surface on the cover. just put some tooth in the surface and removed some high spots.
Used a new felpro gasket and sealer...
Now it is good.
I had the same issue with the Posi lube leaking out first...

There was a post a while ago about gear lube and silicone sealers. Apparantly OE service shops have stopped using black as it doesn't hold up to additives in newer gear lubes. I believe the "ultra grey" is considered better. May help (in addition to removing chrome).