I have several friends that do not own Corvairs. Imagine that!
Anyway, one has a 968 Porsche. The engine is in the front and the transmission is in the rear. They are connected together by a solid member; the torque tube. This tube has the driveshaft which is supported on 4 ball bearing assy's. After a while the bearings wear out but the factory only supplies a new tube unit for the replacement. At a modest price of $3100.00. So I made a fixture to disassemble the tube. I replace the bearings, fabricate new delrin bearing sleeves and re-assemble. All for the inexpensive price of $600.00. I don't have any pictures yet but I'll take some on the next tube rebuild.
This repair is also the same on the 944 and 951 Porsches.