Don't know about the FJ tie rod, but 80 foot pounds of torque sounds like a bit too much my 85 FSM says it should be 67 foot pounds. The knuckle arm at the steering knuckle gets 80 foot pounds. As for the threadlock adding to the trouble I think you are on to something. I once found out as you have that using the threadlock when wet provides a bit of lubrication on the threads and makes it easier to turn. This really throws off the torque wrench reading. With castle nuts and cotter pins you shound not need the threadlock to keep it from loosening.

1985 Toyota Pickup
1994 Jeep Cherokee Sport