I have a huge problem. its finals week and my 81 gl wagon is stuck in 3rd gear. it would stick every once in a while in 4th for the past few weeks but now it wont come out of 3rd. the cable is still connected to the are on the bell housing. linkage pins seem there and cant see anything wrong with the linkage, other than it wont hardly budge.it still drives in 3rd, 2wd and 4 hi and lo work still. Is that a shift fork out of placement? is there anything I can do short of pulling the trans? also were can I get diagrams of the transmission internal R&R?