I am having difficulty changing gear. The gear changing seems to be okay at the start but after a while of driving I start having problems. The gear stick just wont go into the gear. It can take several attempts before I can get it to go in yet the next time I try to change gear it may be okay. It seems to have happened after I changed the clutch cable, I did it myself. There can also be a grinding/rumbling noise when I press down on the clutch pedal. Also last yeah oil came out of the transmission box when the drive shaft was being replaced. As far as im aware that wasnt replaced. Also should I have lubricated the clutch cable