I have had this 360 PA AB set for over 20 years. When I bought it, it had a burned out armature on one of the motors. I eventually tracked down a replacement part and began the process of fixing the motor. But alas the armature was just a symptom on the actual problem. Both chassis needed new bushings. I bought the tools to do the job and practiced on a couple of spare chassis I had. It was a real struggle to get the axle out of the worm gear but eventually I got the chassis ready for milling. Again, alas, my drill press was not tight or precise enough to do the job. After checking the price to rebuild a 2 motor PA at various places I put this project aside for almost 15 years. Last week I was perusing the bay and found a Flyonel PA set for less than the price to rebuild my existing chassis. I bought the set and now my PAs run for the first time in 20 years. And I have a couple of spare A units to re-paint and run as dummys with my other Flyonel sets. A real win win win for me.