rear diff leak

I have 98 z71 that i changed the rear diff lube in. since then it has a very slow leak that i cannot fix, although i have tried to redo it 3 times but it still leaks. i have tried using rtv, cork gaskets and both, with the same result. has any one solved this problem? what did you do?

Thanks in advance

Is it possible that you have a blocked/plugged vent?

i can tell its leaking from between the cover and the case.

That can be deceptive - a leak at the vent can cause the oil to wick down the gasket, leading you to believe that it might be a gasket leak.

thanks, ill take anothes look at the vent line tomorrow

I also need to look into my leak. I haven't looked for a vent & might find it if I look but where is it & can I service it myself if leaking? I wanted to put synthetic in it then I saw a tech bulletin saying not to use synthetic if RTV was used as seal & there is a kit to replace RTV with gasket but there is more to the kit than just the cover gasket & i'm not sure if I can handle the other part of the gasket replacement. I forget exactly what the other gasket(s) were for. Any advice is appreciated. Thanks

The vent isn't necessarily leaking,BUT,if it is plugged,it can cause any and all seals/gaskets to leak.

Are you cleaning the gasket surfaces enough and soaking them in brake clean to get the messy oil off of it? RTV can't seal to oil... Try using stuff called "Right Stuff" Its fantastic for doing that kind of work.. I'll never crack another diff without a tube beside me :D