An engine at least uses cheap specialty tools half the time, the other half you can make do with something as simple as a long breaker bar instead of a chain wrench. Transmissions are something where cleanliness and absolute tolerances are a bit more critical. I simply do not have the space or finances to afford most of the tools a transmission requires to service them, plus you try not to regularly drop and open your transmission for service when your life isn't drag racing.
