I noticed my front differential was wet so I degreased it and the next day saw it was wet again only around the filler plug. The fill plug is as tight as possible so the obvious problem is I need a new fill plug gasket. Two questions: If I remove the plug do I lose diff oil or is the fill point just below the plug? And second, I can't seem to find a gasket online and don't know if it's only available as a plug/gasket assembly (which I can't find either). 2008 Alpha

 

Remove the fill plug to check fluid level, parked on level ground. You should be able to get a new gasket at any auto parts store. The oem part>>>> 14042602
Found here at a lower cost with shipping included: GM OEM Front Axle-Washers 14042602

 

Thanks....I figured if Rock Auto didn't have it nobody would.

 

Every shop I worked at, had multiple gasket/seal assortments for drain/fill plugs. When damaged, match&replace. Take your plug to an auto parts store, they should have an assortment to match the gasket (should be 20mm nylon). Don't forget to check/top the fluid before install.