I powder coated my torque tube and diff. housing. It must be disassembled BUT there is NO grinding involved if you are doing a standard rebuild.
The torque tube stays attached to the differential carrier that holds the pinion gear and bearings. This is the cast part that bolts to the FRONT of the differential housing.
Good powder coat does not chip easily, at least mine doesn't. Before it is coated they heat it up to about 600 degrees to burn off paint and grease. This temp will destroy any seals or lubricants still in it. After spraying the coating on it is baked again to liquify the powder and bond it to the metal.
I have pictures if you want.
Paul Wisner
