Can't engage reverse gear

[Buddahman]

I have a suzuki Jimny and I'm finding it more and more difficult to get into reverse gear. It started about a month ago, at first it was only reverse gear but now I have noticed that the difficulty is whenever I push the gear lever backwards - in other words into gears 2, 4 and reverse. When I push the gear stick forward into 1st or 3rd it seems to be ok - crunchy but ok. First thing in the morning they're all ok - all crunchy but ok - but after about 5 minutes driving, first reverse gear becomes difficult and then 2nd and 4th gears become difficult. When I haven't driven for a while then it becomes easier once again. Have checked gear oil level.
Does anyone have any inkling as to what that might be?
Thanks,
Buddahman.

[Doggy Doo]

Could be something as simple as the gear linkage as moved, had this before on a car and noticed it had only moved about 5mm but that was enough to cause problems.

[Mender]

Another possibility is that the clutch friction plate is stuck to either the flywheel or the pressure plate. I had this on a Fiat 900 years ago, and had exactly the same symptoms as you have.

Also, it may be that the clutch isn't releasing properly when you push the pedal down, so it may need adjusting.