I would not do it that way .If you have ever seen whats in the auto box in way of this pawl its not that strong . Anyway i would not do it this way ,the torque is so great on the flange nut ,.Its up to you ,,so if the gearbox plays up after you will know why. The manual wont tell you to do it this way .I would make a fixture from a scafold pole and a good clamp . And another factor is your flexi joints will take all the force ,,so it will do these a world of good .