I went out and bought 3 bottles of the Mobil 1 75W-140 gear oil for my non LSD 06' 1500 Hemi. The auto parts store said they cannot even order a gasket for it (12 bolt) and that it's a dealer only item. They aslo said a gasket was not nessecary. They sold me a tube of Grey Permatex and said that would be all i would need. But i can see a gasket between the cover and the housing.

Before i attempt this, should i wait and buy the gasket from the dealer? or will the Grey Permatex be fine? I just do not want to have leaking issues.

 

You don't need the dealer gasket. Just use the Permatex RTV, and you'll be fine. When I replaced my stock diff cover with a Trans-dapt cover after doing my fluid change, It came with a gasket, but i chose not to use it and used the Black Permatex RTV instead. No issues with leaking.

 

Just did it. Used the Grey Permatex. Crossing my fingers their will not be any leaks!

 

I don't know why the dealer even offers the gasket, all they do is RTV it as well...

 

My dealer didn't have gaskets. Just told me to use the RTV stuff. Well I hate cleaning that RTV stuff off when I take things apart so I went to NAPA and they ordered me a gasket for the front and back. So now the next time I do a diff oil change, I no longer have to spend forever taking the old stuff off.