Well my L979 finally stripped the spur gear. I think what happened was the screws on the motor came loose, and the motor shifted a bit and the pinion chewed off the edges of a few teeth on the spur gear. Interestingly, I noticed that the replacement pinion gears I had ordered were 14 tooth, while the original was 12 tooth. I tried one and it meshed with the replacement spur gear much better than the 12 tooth pinion had. Once I assembled it, the gearbox was smoother and quieter than it had ever been. I haven't checked to see if the car is any faster with the slightly taller gear ratio. I find it interesting that there are different size pinions and that people are finding differences in gear mesh, WL must have made some changes at some point? I do hope that this improved gear mesh will make the gears last much longer.
Also this is the battery I use, I just changed the connector to Deans. It fits almost perfectly and offers a noticeable improvement in battery life. https://www.hobbyking.com/hobbyking/...dProduct=37346
I'll also offer my opinion on upgrades, now that I've had mine about 5 months. I can't seem to find any 390 size motors that offer improved performance. There are some 390 size crawler motors, but that will just give more torque and less speed, that's just counter productive in this application. The gears are already delicate as it is, so more power is not really a good idea.
I think the best things to do are properly break in the motor, replace the bushings at the wheels with bearings, and install some 65mm oil filled shocks. The bearings make some difference in speed and efficiency, and they will last longer than the bushings. The shocks make a huge difference in handling, the car is much steadier over rough terrain. Unfortunately there aren't many options for front wheels and tires. You can get some Tamiya buggy front wheels that fit the front spindles, and get the correct bearings for those, and the Hobby King Sand Storm buggy front wheels will work too I think. There are of course plenty of options for 12mm hex rear wheels and tires. I think the L979 wheels and tires are decent enough for these cars, they don't have great traction but they do the job.
I just don't see the point in trying to upgrade these cars any further than that, it only becomes a waste. The brushless L202 is like an after thought, it wasn't designed from the start to be brushless, the gearbox is too weak so it won't last. I'm happy with my L979 the way it is now, when I want more power, I have other cars that were designed to be brushless.
If you want brushless speed and power, then buy a car that was meant to be brushless. I know I keep recommending HobbyKing stuff, but I haven't found better deals anywhere else. You can get the Hobby King Turnigy Brushless 1/16 4wd buggy ready to run for $90, and it blows the L9x9 cars out of the water in every way, yet costs less than an L959. Or the Quanum Vandal for $120. That's less expensive than an L202, yet it's 4wd, bigger, far more powerful, and very durable. I have the Vandal XL with 135mm tires on it, it's so much more powerful, durable, and upgradeable. Sometimes if you buy the almost ready to run car and the radio system separately, it's even cheaper.
I just don't see why anyone would spend money converting an L9x9 to brushless and then keep replacing parts, when that money could buy a way better car to begin with. I mean I love my L979 for driving around my front yard and in the street, and driving on the beach because I sealed the gearbox and it's fun in the sand. But beyond that, when I want a faster car I go to my rally car or Vandal buggy, they don't break constantly and are plenty fast, the rally car handles way better, and the buggy can crash and flip and land upside down without breaking.
Upgrade your bearings and shocks and enjoy what you have. If you want to go faster, buy a car that's brushless to begin with. The extra you spend on a new car instead of just the l202 kit, will end up being cheaper when you aren't buying new gears and parts every time you drive the car.