Plastic diff gear in losi conversion

[Rcrcrus]

Hi can any one give me advise on on the center plastic diff gear. I ran my losi 8t with a losi conversion kit for the first time this weekend and by the time i got half way through the final 3 laps ahead of everyone i striped all the teeth clean off the plastic gear. I've now fitted a metal center diff gear, lowered the braking and throttle on the speedo. Is this the right way to go. If not where can i get a new plastic gear before this weekend as i have 3 days of racing at stoneligh park and want to run the electric.
I am sure they must of supplied a plastic gear for some reason. And can anyone recommend how to fit a braking setup.
Cheers