904 Transmission Stopped Going Into Gear

First timers might be overwhelmed by all those different parts. Rebuilding a 904 is a good experience for the first time, but that much disassembly is more than I would recommend for the first timer. I wouldn't remove the governor support or rear band anchor or even the tailshaft housing. And I wouldn't disassemble the valve body either. 9 out of 10 904 trans lose third gear and have a delayed reverse. Or they slip going forward. Those two drums are the first out after the pump. And for a /6 904, I would seriously consider installing V8 drums, or at least use lower ribbed forward pressure plates as top plates on both drums. And when you assemble the pump, use a giant adjustable hose clamp to align the two sections.