Aloha mates.
I want to install a HL turret gear in my Mato Sherman. It's turret turning speed is garbage, and so is Derek's & Franks. I suspect something inside the stock Mato gearbox is crappy.. 

I'll probably just swap one out from another tank, but eventually I'd like a new one. If anyone has a spare, let me know!

I'm sure I can help out here. Your not referring to the ring gear, but the motor, correct?

Either way, I can help.

Stinger

Yep! The motor gearbox thingy contraption gigamajig.

I'll be interested to seeing how this turns out. 

Don't forget to take pictures Strato!  

If just the electric motor itself is not working, I've had good luck replacing it with the turret rotation motor from Tamiya - just open up the gearbox and swap them out, (the worm gear on both motors is the same).  It comes in handy if you're using Tamiya electronics (like in a Mato Sherman conversion) because then you then have the correct traverse plug to fit the new electronics.  I've gotten them from jr-rc by themselves; but also taken them from stock Tamiya turret traverse units.

If Stinger can't help you out; I know I have a spare Mato turret gearbox you can have. -Mike