[srode]

New 2004 2500HD with a leaking rear differential fill plug, oil all over the spare tire. Will take it in to the dealer to top off and figure out why it's leaking. I snugged it up for now, but it felt like it already had about 25 ft/lbs on it which is the torque spec I think. Is the plug supposed to have a gasket on it? Probably not much more than 500 miles on it, so don't think it would damage anything yet, at least I hope not! Edited by: srode

 

[Wiseman]

My 2003 2500HD has a nylon gasket on the rear differential fill plug.

 

[sixfoot]

Mine has a nylon washer on it too. It leaked after I changed the oil in it. I had to go back and tighten it up some more to make it stop leaking. I was a little surprised too at how tight I had to have it to get it to stop leaking.

 

[srode]

Checked the level, was 2" below the fill hole at 600 miles, called the dealer, they let me get two free quarts of grape juice to fill it up before I drove it to them to check what the deal is. Found it had the washer. After filling torqued to the 25lb spec, then about an 1/8 turn past, to the dealer Friday for inspection. Hope it didn't hurt anything, probably won't know till I change the fluid and see how much metal comes out.