check your pinch bolt on top of the g/box selector shaft is tight,also if you look at the selector shaft going down into the top of the g/box cover under the oil seal is a needle roller bearing which seizes up,you have to remove the 10mm bolts holding the top cover onto the g/box for access and if you are careful and give it plenty of oil and release oil it can be freed off,if not I dont think you can get these bearings separately now and you have to take the whole top selector assy. unless you can get one from a good scrappy
cdc, February 2012