I recently purchased a never run 6-11319 Legacy K4 4-6-2 Tuscan red engine from a seller. After searching the web for any issues I found this: https://ogrforum.com/topic/159096765274967339
and proceeded to inspect my gearbox finding of course this very issue where the gearbox idle gear moves away from the motor worm gear leaving only a small edge of contact. I decided to use a teflon washer to prevent the idle gear from moving sideways. I sanded down the washer until the right thickness was achieved to allow only slight clearance with the gearbox. Then I cut a 45Deg. Section out of the side of the washer to allow it to snap over the axle and remain in place. This worked great but I made one more change ( not shown in pictures). I cut slots in the motor bracket screw holes and mounted the motor left of centerline to better line up the motor worm gear with the brass idle gear. This also worked great. I believe that if I had not taken these actions the gearbox may have destroyed itself in short order. Upon reassembly I used a generous amount of Marine grade Teflon grease. ( I have a boat 🚤 😉 so I think this grease will work great. )
body of engine
engine chassis
Brass idle gear pushed all the way up (in picture) where it will stay once the washer is added
brass idle gear pushed all the way down (in picture) showing how far it can move leaving only a little engagement with the motor worm gear
Teflon washer used to prevent idle gear sideways motion
Teflon washer installed
