I did put a drain plug in! I'm not sure why all trans pans don't have plugs My Daughter has a 99 GMC 1500 (new style) It came with a trans drain plug, the problem is, FROM THE FACTORY<WITH ONLY 30.000 miles, You can't get the DRAINPLUG OUT!!! I had to weld a large nut to the drain plug just to get the org plug out!! When you get these trucks serviced under warrentee, mark the plug before You take it inforservice. You might be suprised!!