Thanks guys, problem solved. I can't believe how I can spend 2 hours doing a 5 minute job. I tried a 5/8 bolt with2 nuts jammed on it but could not break it loose. The torque spec is only 22 lbs but it was really tight. Finally went to town and bought a 17mm allen/socket and thanks "InThinAir" that is the correct size. I just wanted to check the oil level as the truck only has 2K on it but I am leaving for Alaska in a couple of days. The fluid level was perfect. Thanks again for the help.