Update - Called Customer Service to report my problem. They are not aware of any production problem related to the GP30 run. Since I can repair it myself, they're sending me 2 - new trucks. I still think that these specific engines may have a "production" problem in which the plastic knuckle is simply not pressed onto the truck work gear shaft as tightly as necessary for reliability.

I own 2 - GP30's (Santa Fe) purchased approximately 3 - months ago. I've had 2 - plastic knuckles come loose from the small shaft on the truck tower (worm gear). I ordered and replaced the first one but now I'm getting worried that this is a production problem. Is anyone else having this problem? Anyone know a way to reliably glue the plastic knuckle back on the metal shaft? I know Gorilla Super Glue doesn't hold.