Rear control arm install: how the hell...

[Tailwind]

+1 what imhighlander said. I think I tried putting a short Torx bit on the shaft and counter holding it with a small crescent wrench. Then estimate the torque using an open end wrench. Otherwise, put a wood block on the jack and load the ball joint then wrench it. Be careful not to hit the backing plate. Any tweak of that will result in the rotor scraping it. Ask me how I know.

[steved0x]

Often times you can torque it just by pushing it from the bottom with your hard and tightening the nut. Once it draws the tapered shaft in there, it will stop turning. IF that doesn't work, otherwise I use my hockey puck on the jack and lift the control arm from under the ball joint to load it, and then crank down with a box wrench