I just finished with an upgrade to improve the performance of my MDC/Roundhouse Shay. The trucks were pretty noisy, making a growling sound at all speeds, and I found that the main cause is slop in the worm shafts. The stock design, which is square plastic slots and a brass shaft using the bottom plate as a retainer, allowed free up and down movement of the shafts. That's a bad thing. So, I decided to upgrade each truck with a steel shaft and NWSL bronze bushings.
The difference between the two trucks is pretty obvious. I removed most of the original shaft stands from each truck, opened holes in the appropriate locations for the new bushings, pressed the original worms onto new shafts, and glued the bushings to the truck with the worm shaft permanently in place. This new design eliminates all up and down slop and allows the shaft to rotate more freely. The result is a quieter and smoother running Shay, which now gets almost all its noise from the central gearbox. This is a fairly difficult upgrade, so I wouldn't recommend doing it to your own Shays unless you have the skill and tools to do so (if you do, it's worth it).
All that's left now is the very cheap, slightly off-center wheels which cause the engine to wobble. Best I can do there is counter rotate them.
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Great idea Darth, hats off to you. I have a 2T that literally rose up in the rear when moving forward. the usual NWSL upgrades corrected most that, but this takes in a step further.
Thanks for this.
"The true sign of intelligence is not knowledge but imagination."-Albert Einstein
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