just puled my 36 ton Shay out of storage...

[bremner]

    

The top of the trucks crumbled apart! I don't see any replacement parts to correct this issue, and since I bought this 25 years ago from a defunct hobby shop, do I have any options on fixing this unit?

[Stokerman]

Yep, you can still get the upgraded replacement trucks for these Two-Truck Shays, though they are pricey to say the least, but worth it if you want to run your Shay!

[Greg Elmassian]

Unfortunately not unusual, sorry!

[wraujr]

Out of curiousity, was the cause ever narrowed down.  Was it the type of plastic or maybe a lubricant that attacked the plastic?

[genei123]

I feel your pain. A little over a year ago I bought a "New" Shay and it ran about 40 feet and the rear truck fell apart. You can get the die cast trucks here: 

https://www.ebay.com/itm/144707130062?hash=item21b13792ce:g:h4wAAOSw0plioVNz&amdata=enc%3AAQAHAAAAoKRbF02r7hEdj8j4uHLm7C5hNvpFPAosu9r8ebbRu0iQedBjvii%2BnRA36Nct6OewRUDL2ub9EwmQdfEtJTJrsoCFScXDJFvhNP7WG%2F5A4r%2BVlhLueq8tR%2BoY9hAj3i%2BdW6oV1INO9byNB6PwoMiNkgh4lyt3rY5SwTKgB6WVUTBfJEZBMXYP%2FYRlPrILnfj5z89JQXgxHVOffB%2FKY0M3xSg%3D%7Ctkp%3ABk9SR7DRt_W_YQ

I think he has the lowest prices.

[Greg Elmassian]

Poor quality run of plastic, it happens from time to time... pretty consistently bad on the first run.

[Waikiki968]

I have one that you're welcome to.  The replacement trucks are the right solution tho...