The bearings at the rear of the torque tube are lubed with the same oil as the differential. I use a light grease to protect them at first, splash will lube them right soon after the diff starts to spin. The bushing at the front is lubed with transmission oil..and yes, I lube that bushing with a light grease as well. It takes a bit of time to fill the "ball" and have the splash start working. Assembly grease seems to do the trick. Never let any thing run dry. Ever. Transmission gear oil will not stay on the bushing long enough(my opinion) so a bit of grease keeps my conscience happy.
