Yeah, Dude, if yer gonna go brushless, there are a couple things you'll want to upgrade for reliability. First, the drive pins on the stub axles. The stock rolled spring pins break too often under brushless power. You have a hardware store nearby? See if they have K&S Precision Metals "Music Wire" stock #504, 0.062in (1.57mm). This is just solid metal rod and comes in 30in lengths, bundles of three. It's only a few bucks and will last you a lifetime. Just cut them to length. Note that they will not fit tightly and tend to fall out when you take the wheel off. But, they will never break.
The other thing has to do with the differential. You have a plastic gear diff, even tho the internals are metal. When you open the diff, you will find the small "planetary gears" in between two larger bevel gears. Behind the bevel gear is the end of the drive cup and it is held in place, and driven by, another pin. That pin may also fail. It can be replaced with stock #502 Music Wire 0.047in (1.19mm) and should never give you any more problem. If you cannot find the music wire locally, send me a PM and I'll arrange to send you some.
However, depending on how and where you drive, and how your slipper clutch is set, the plastic diff gear can get stripped. If that happens, get the Brushless Evader (now discontinued, but parts are available) all-metal differential:http://www3.towerhobbies.com/cgi-bin...?&I=LXBURC&P=7
Yeah, it's $17, but it will never strip. The diff gears inside need a good lube. Get some of this: http://www3.towerhobbies.com/cgi-bin...&I=LXBLNN&P=ML
(use it in YOUR diff NOW if you want to save your gears) Lube the tranny gears as well. The car comes from the factory practically dry. Pick up some silicone shock oil too. The stock 20wt is a little light, I use 35wt.