i have A15 with 60A 5 speed box and standard cable clutch.
Normally the clutch and gear change action is fine, but after a period in traffic or engine idling for a while and the electric fans are working to keep it cool it gets difficult to get in gear, grinds the teeth to get into reverse.
Why is this ? and can i just adjust it out ?

Sounds like it needs adjustment. In a B310, there should be only 1 inch (25 mm) play at the clutch pedal

Definately sounds like adjustment. I had the same problem with mine. It seemed fine when it was cold, but when I jacked up the back wheels, they still slightly rotated when in gear and clutch fully depressed.

ok, thanks for responses, i'll have a look at the slack and try adjusting it.
be nice to have a simple problem for a change