It’s a known issue; ……the Lionel Legacy K4 has an issue with the gear box going into self destruct mode…..the compound gear box has an idler gear arrangement that walks away from the worm gear on the motor……I’ve developed a fairly simple solution that’s non-invasive, and will have good longevity. The new fix requires no wheel pulling, no gear pressing, no harm to the chassis, …..one small hole must be drilled into the side of the gear tower,……the fix is a brass flat bar stock, with a U shaped bushing to cut down on parasitic drag of the flat bar up against the gear it’s guiding towards center……I believe we’re just touching the tip of the iceberg with issues like this on Legacy gear boxes that have a similar construction and compound gear arrangements…..this fix will apply to more models than just the K4, that I’m sure of,…..thanks to David Ross, for sending his K4 that had completely lost gear engagement and is now out of field testing and doing fine. Also, thanks to John Will sent a test sample that allowed me to have more than one chassis with the same problem….The fix can only be applied to those locomotives that have not totally destroyed the top worm wheel, or totally wallered out the intermediate shaft beyond repair ….it can however, be a preemptive first strike package, in other words, new or lightly used engines will benefit from the fix, as this part will keep the gear centered. Testing shows zero additional wear using Mobil 1 synthetic grease in the gear box…test was conducted 16 hours, two straight 8 hour runs, back to back,…as of this printing, I do not have an infield solution, as the parts will have to be custom made for each application, and the measured offset is different between examples, so as of this moment, chassis will have to come to my shop for fitment ……I think I covered everything I can think of, and I’m sure we’ll discuss this more on this thread,….
Pat
