I have a r151f with the same problem, havent torn it down yet but the previous owner said no 1-2 but 3-4-5 was just fine. I can get the trans to go into all 5 gears shifting it, but 1-2 and r dont engage. (shifter spins around 360 degrees as well, doesnt make it any easier) but if I spin the input shaft it only wants to spin in one direction. Feels like its locked solid the other direction. definately needs new bearings too, but for $50 with t case and bell housing couldnt go wrong. think its junk?
