I just looked at a torque tube 3 speed transmission that I've got stashed away. There's a HUGE drain channel at the bottom of the ball socket area that allows lube to drain back into the main transmission case, so less than 1/2 inch of lubricant can accumulate at the very bottom of that area. If you want to drain that tiny amount for some reason, drill and tap a hole in the bottom of the transmission case fora small pipe plug- - - - -maybe a 1/4" NPT. PM me an email address, and I'll be glad to send pictures.
Jerry