Yup, it worked! I put the bike in 1st gear and left it on the lift. Gave the wrench a good snap and it loosened the jam nut. I don't have an impact wrench but my long Craftsman torque wrench did the trick. Oh and I bought a 11/16" deep socket at ACE Hardware for the job. 5 bucks well spent.
I was expecting the service manual to tell me what tools were needed but there no such thing in it. Oh well .........
Thanks to all for your help. My clutch used to jerk/lurch in low gears after the bike was already in motion. The clutch adjustment solved the problem. I have 9,600 miles and never touched the clutch basket until today.