We had an extremely similar problem this season. We competed at two Regionals for the first time this year and used the new AndyMark14U KOP chassis. We used the standard Mini-Cims with 2 CIMs on each side of the drive train.
2 gears stripped
During our last Regional, in the semifinals and finals, we basically could not drive on the right side. During the finals, we investigated and found that the 14-tooth gears that are attached to the Cims were stripped bare. Unfortunately, we had no replacements so we had to just roll with it.
Here is a link to the specific gear that we had such trouble with.
CIM gear, 14 tooth
We were planning on emailing AndyMark in the future to let them know about the situation.
We attribute it to poor lubrication. We accept some responsibility on this. We should have greased them during both Regionals. We have played a combined about 45 matches in 2 Regionals (finals reached in both). However, there was a very small amount of grease provided in the package initially. So even from the start, we believe they were poorly lubricated.
Anyway, we have bought replacements for Champs and will put them in there.