I found some CANON ballbrg shafted 12v motors at a surplus house ,turned some flywheels with the end bored for a press fit of the existing drive components , runs so smooth and really coasts . It fit like it was made for it . Even used the original motor clamp or hold down strap .On the truck mount , when you take the tower apart there is a U shaped metal piece in the top , I soldered a screw to it , reassembled , works like a dream . I used the NWSL wheelsets , but I have also repaired the gear that splits by honing out the inside where it slides over axle , then pinned the gear and there is a brass tube that will fit right over the shoulder of the drive gear , I did this as an experiment waiting on the NWSL wheelsets to arrive. These F-9's can be detailed very nicely and are a beautiful molded nose model . For 70's vintage model pretty hard to beat , I have some with LIONEL bodies to be installed on this power drive chassis. You may be able to find these little powerful motors , they were 3.95 , I only bought about 8 and when I saw how good they would work , went back to buy the rest maybe 20 or 30 and they were gone 3 days later .