I guess when you say "leak at the torque tube' you mean a leak from the transmission into the rearend, correct? If you mean an external leak then it has nothing to do with the bushing or internal seal. Anyways, the leak into the rearend requires a new seal inside, not necessarily a new bushing. However to get there you have to remove the old bushings. The Oakie assembly does the job without having to take the whole rearend apart.
