Originally Posted by RealGambler
A long time ago, I did order a 9T pinion from HK and it didn't work (still using old pinions from burned motors). It may have been another one, but I think it was this one. Just telling you because you may want to have a "plan B", just in case.
Thanks for the heads up. My prior plan A is actually my plan B
mCPX 9t pinions should fit too, but they cost like 5x more.