RCM Pinion idea
 

i have been using rcm 14t and 15t pinions in my brushless mooge since its creation about three months ago.i have been breaking quite a few pinions.one was due to my motor mount being loose but the others have been a bit odd.nothing loose,nothing bent.after taking my trug away on holiday with me where i got to do alot of driving and tweaking the set up i noticed a possible issue with the smaller pinions. they are hollowed out in the center which makes them weak and the teeth prone to snapping off. i broke my last available 15t two weeks ago and put in a 17t which doesnt have the hollowed out center section.since installing the 17t it hasnt missed a beat.the trug has taken some mean hits(the 8 metre kicker at arccc is vicious:diablo:) and the pinion has held up far beyond what the smaller ones did.
maybe making the smaller pinions without this hollow area will make them alot more durable? just a thought:yes:

First I've heard of it, food for thought though. That said, I have a 11T I use from RCM and can't see any hollowed out bit to speak of except for the shaft bore and the set screw. It's served me well over the years :)

they are hollowed out about .25 of an inch from the gear end..

I also had a 15t mod 1 pinion broke a tooth off,same kind you speak of. I emailed mike he sent a new one. I never had it happen again. I have several of his pinions,no other problems with them.
phil

I have a dozen or so RCM pinions I use on 5 vehicles w/not a single problem

here is a pic of one of my bung pinions. the hollow section i mean is directly under the teeth.i know there is need for a hollow for the bore.

This type of failure is relatively uncommon, but it happens(and not just to my pinions). I replace these pinions when they fail like this. It is a simple matter of math, as there is no such thing as 100% success rate. I have easily sold 8,000+ hardened pinions over the last few years so a 1% failure rate would yield 80+ failed gears(haven't seen even half this many failure total). The weight reduction pocket doesn't span the entire width of the teeth(pocket depth), and is simply not a factor in this failure.
Every so often, a gear gets passed through production either without getting hardened enough, getting overhardened or otherwise out of spec. You were simply one of the few. Send it back and I will replace it. :)

So Mike, will all of your future pinions have this "weight reduction pocket"?