Take everything loose you had apart, put the shifter in the normal 3 o'clock neutral position, put the shift levers on the transmission in neutral and put things together again and see what happens.
As for the jumping out of gear problem during engine braking, I would suspect a bad pilot bearing or no pilot bearing or a clutch housing not centered. I always use a dial indicator to check the circle as well as the flat part of the clutch housing.
Last edited by crenwelge; 09/23/2010 12:37 AM.