Just an FYI, the 8 tooth pinion from Heli Max has been discontinued. They're making a 9 tooth now. I haven't tried them, but they should be workable...although the 8 was a very nice mod to a Tam. TU.

If you've got a Spektrum radio which is digital. One can adjust the travel (on a Spektrum it's the "Travel Adjust") to any percentage you want, but it doesn't work out too well in battle with lots of hits on the tank. At a high number of hits, it pretty much won't move. Not the greatest option, but good if the only one.

As to DaveBCool, I've had some success drilling out pinions with a small vise and a cordless drill. I too had ruined several pinions, but found that if I didn't drill the pinion all the way though from one side (i.e. drilling 1/2 of the way from one side, and then drilling the remainder from the other side), they worked pretty good. Kind of low tech, but it worked.