I do not come on here very often but I read this thread and this is what I bought for our turning point hitch.
AFF 2-1/4" 6 Point Wheel Bearing Locknut Socket, 3/4" Drive, 18520. I talked to Lippert and they told me to torque the castle nut to 50 ft lbs. I had to buy a 1/2 inch to 3/4 inch adapter to fit my torque wrench. Save the cotter pin and get a couple new ones in that size. Don't use the old one. I purchased the socket from Amazon. Good luck with it.