I have started rebuilding a tra 12d that had a blown head gasket and a broken governor gear. The only manual I have is for the 10d, it says there should be a ball and spring in the end of the cam. However when I tore the engine down there wasn't one..... It appears to me that someone has been in the engine previously, and I wonder if they lost it resulting in the governor gear to fail. Or does the 12d not have one from the factory and the governor gear is just coincidence?