Was having trouble with the power antenna. Bought the new mast, took the broken piece out of the drive, the new one refused to engage. Oddly, the nylon gear strand on the new mast curls opposite the proper direction (teeth toward the outside of the arc) so I took the whole thing out, fed it in manually with the drive cover off until I was sure it would spool correctly, put it back together and put it back in the car. Of course the first thing it did was spit the gear strand back out again. Twisting the mast helped not at all. With my lovely assistant turning the radio off and on again many times, I finally gave it up and disconnected the motor. My guess is the drive gears must just be worn enough to slip past the strand teeth, though they didn't look it. Is there a magic trick to this? Is that drive gear available on its own or do I need to find a whole new drive unit?