The 4* has an aluminum gear,
Problem with hardened Aluminum is once the original shape is lost, there is no way to get it back without retreating it.
You can get a 3rd party 3/16" thick gear for $45 from tntlandinggear.com.
My LT-40 is a tail dragger, and has a nylon gear with lots of spring to it. I don't think I have ever had a hard landing with it, except the one time I missed the runway and plowed into a plowed row of mud, ripped the gear right off. Good example of why nylon bolts are a must. Had new bolts in and flying 5 minutes later.