Allison Transmission Questions icrman, I do not know if it is a transistor nor do i care since we do not repair the boxes, which by the way are called ECU's.The voltage required to run the solenoids is 9.6 volts. It is a Motorola. The planetaries are made of cast iron and the pinions are hardened steel.The clutches can be be what we call Dynax material and some graphite. There are brass plates even in some models. I know what you are trying to do but may I ask you why I would need to know this? I do not care what these are made of, my concern here is to ansewer operating questions to help people so they can save money and not get ripped off.If you read my first post, it says i enjoy answering these questions, but you are taking the fun out of it. I take a week sir because I work many hours and I do this on my spare time at home with no pay. What about it people, would you like me spending more time with this needless information, or answer your question. I hope it is answer questions and meet you. Please let me know hat you think. IC, I dont mind you answering but you are giving wrong answers in some cases. I work and deal with the allison engineers on a daily basis. Well sorry to all the other wonderful people and I look forward to answering your DIAGNOSTIC questions. Thank you. P.s. just say the word and i wont come back. Let IC and trans answer if you think they can which I do not think they are 100% correct and I would challenge them to see if ANY of my answers are wrong.