The threaded collar at the rear of the torque tube ball collar (see link to picture below) keeps backing out, resulting in a transmission leak. Any suggestions on how to make this thing stay put?

http://lymanhall.smugmug.com/Trucks/1953-Chevrolet-3100-Truck/i-PHq3jZm/0/L/Ball%20Collar-L.jpg

I can't find a torque value for tightening the collar, and have been using a pair of soft-jaw (curved-jaw) channel-locks. It gets loose after only a few miles' driving.

Thanks


1953 Chevrolet 3104 1/2-Ton
In the Stovebolt Gallery
More pix