On the JX servos I've been running, it's the second gear that is stripping, but the first gear also starts to show signs of wear, the following is a sample gear that has seen 14+ months of racing in a 1/8 buggy when I started to notice some slop forming under the servo arm and this is what I found, though technically the gear hadn't stripped yet, you can see the sharp shark teeth toward the top:



I had noticed that the grease in the gears was all black and gritty, I almost wonder if it would've been a better preventative to regularly clean the gears and re-grease them, thinking that might allow them to last longer. The servo on the right is a brand new donor servo for a fresh set of gears and fresh grease.