Originally Posted by yjb63
What's the difference between a piston with full teeth and a piston with half teeth?
Ok dude, seriously, you need to start doing some of your own research. Even a simple google picture search would answer that for you... unless your question was what are they used for, because that's actually a good newbie question. Half-teeth pistons are used with helical gearsets. Full teeth pistons are used with normal gears.
There is literally TONS of information on different mechbox components scattered throughout the internet. If you don't know any of this stuff, stick around for a while and READ.
Some suggested sites: