I tried to find an exploded view of the trans (using my phone) but couldn't find one that clearly shows where the input clutch/piston is. If I could easily get to it while replacing 4th hub maybe I'd do it, but I'm certain so many other things are worn it wouldn't be worth the effort. I wish I had the time and means to completely rebuild, more for learning than anything since the vehicle is pretty rusted. I'm just trying to make it fully functional so I can sell it.