The aluminium idler(or whatever I would call it) in the rear gearbox was the first to go in my df-03. IMO the bevel gears do just fine as is.
TG
HI!... I must have a newer version then. I have no aluminum idler in mine. All gears are plastic except the main spur gear shaft gear which is steel on mine. There's guys on other RC sites that are destroying the bevel gears front and back and melting the large diff gear in the rear. I've been told to stay away from the front one way due to it destroys the front bevel gears.
HI!... Well some more parts came in today. I got the 3RACING front/rear composite shock towers, one piece inputs, driveshaft, front "A" arm support and rear gearbox support. I still have to get the higher voltage electric fan for my ESC and the CVD's.