Let me shed a tiny bit of light on the subject.
The torque rod does exactly what is said below.
Ha Ha, it is not so much for axle rap as it is to keep the diff located the same distance from the steering box so when you brake it dosen't steer.
A couple of Moab trips ago the bolt on the frame end kept working its way out and it really made a difference in handling. The problem is if you lift the truck the arm is too short. AOR had a kit for a longer torque arm with a heim joint to increase articulation, but they are now seemingly out of business.
To solve this problem, I cut a short piece, about 3/4 inch, out of a Honda Accord tie rod, I think, because it was a similar diameter and then welded into the torque arm. Now it doesn't allow the axle to move and it doesn't pull the axle back.
Is it possible that the reason that I have not broken my J-arm is because I still have the torque rod?