Peugeot 107 - Gearbox Problem??

[jimmyV8]

I have been using my girlfriends 2005 107 this week as I am inbetween cars, however this morning half way into my commute it became a real challenge to engage gears 2 - 5. It will go into gear with some effort but there is some resistance and almost a slight crunch. If I match the revs when changing down to 4th it will not engage without grinding. The car has done nearly 40k miles mostly round town use until now. Could it be a worn clutch? Or maybe a synchro/selector issue? Gearboxes are always something I have taken a wide berth of, so I know very little about them. Any advice would be great.