Anyone know the thread size on the grease zerk fittings on a 2004 Duramax?

Thanks http://www.dieselplace.com/forum/smileys/Big Smile.gif
Jim

I believe they are 1/4" 28. Thats the most common. could be metric, but I doubt it. Standard zerks are either press in, 1/4 28, or 1/8" pipe. You can re-thread the metric sizes to standard they are real close.

I think they are 4mm....Edited by: SaguaroKid